CMOSTEK CMT2157AW Manual
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CMT2157AW CMT2157AW 240 – 960 MHz (G)FSK/OOK Stand-Alone Transmitter with Encoder Features Applications Low-Cost Consumer Electronics Applications Very Easy Development with RFPDK Home and Building Automation All Features Programmable Remote Fan Controllers Embedded EEPROM Frequency Range: 240 to 960 MHz Infrared Transmitter Replacements FSK, GFSK and OOK Modulation Industrial Monitoring and Controls Symbol Rate: Remote Lighting Control 0.5 to 100 ksps (FSK/GFSK) Wireless Alarm and Security Systems 0.5 to 40 ksps (OOK) Remote Keyless Entry (RKE) Deviation: 1.0 to 200 kHz Output Power: -10 to +13 dBm Sleep Current: < 20 nA Stand-Alone, No External MCU Control Required Embedded 1920, 1527 and 2262 Data Encoder Part Number Frequency Package MOQ Up to 7 Configurable Data Pins for Push Buttons CMT2157AW-ESR 868.35 MHz T&R 2,500 pcs LED Indicator for Low Battery Detection and Transmission CMT2157AW-ESB 868.35 MHz Tube 1,000 pcs Sync ID Auto-Study with CMOSTEK Receiver FCC / ETSI Compliant RoHS Compliant 14-pin SOP Package Ordering Information More Ordering Info: See Page 26 Descriptions The CMT2157AW is a true single-chip, highly flexible, high performance, (G)FSK/OOK RF transmitter with embedded data encoder ideally for 240 to 960 MHz wireless applications. The device integrates a data encoder that is not only compatible with the most common used encoding SOP14 format of 1527 and 2262, but also a more efficient, flexible and powerful format of 1920 designed by CMOSTEK. Up to 7 configurable push buttons are supported in multiple button modes. When pairing the device to CMOSTEK LED 1 14 XTAL VDD 2 13 CLK GND 3 12 DATA transmitter remotely by end customers. An embedded RFO 4 11 K1 EEPROM allows the RF and encoder parameters to be K7 5 10 K2 K6 6 9 K3 K5 7 8 K4 receiver, the synchronization ID can be programmed into both of the transmitter and receiver during the manufacturing phase, or studied by the receiver from the programmed into the chip using the CMOSTEK USB Programmer and the RFPDK. Alternatively, in stock product of 868.35 MHz is available for immediate demands without the need of EEPROM programming. The CMT2157AW is part of the CMOSTEK NextGenRFTM CMT2157AW family, together with CMT225x series receivers, they enable ultra low cost, low power consumption RF links. Copyright © By CMOSTEK Rev 0.8 | Page 1/31 www.hoperf.com CMT2157AW Typical Application CMT2157AW X1 D1 VDD 1 ANT XTAL LED 2 L1 L2 C2 C0 C1 3 4 SW7 5 SW6 6 SW5 7 VDD CLK GND DATA RFO U1 K1 K7 K2 K6 K3 K5 K4 14 J1 1 VDD 13 CLK 12 DATA CLK 2 DATA 11 SW1 3 10 SW2 4 9 SW3 8 SW4 Note: Connector J1 is for EEPROM Programming Figure 1. CMT2157AW Typical Application Schematic Table 1. BOM of 433.92/868.35 MHz Typical Application Value Designator Unit Manufacturer - - CMOSTEK 26 MHz EPSON Descriptions 433.92 MHz U1 CMT2157AW, 240 – 960 MHz (G)FSK/OOK stand-alone transmitter with encoder 868.35 MHz X1 ±20 ppm, SMD32*25 mm crystal C0 ±20%, 0402 X7R, 25 V uF Murata GRM15 C1 ±5%, 0402 NP0, 50 V 82 82 pF Murata GRM15 C2 ±5%, 0402 NP0, 50 V 9.1 3.9 pF Murata GRM15 L1 ±5%, 0603 multi-layer chip inductor 180 100 nH Murata LQG18 L2 ±5%, 0603 multi-layer chip inductor 22 5.1 nH Murata LQG18 D1 D0603, red LED - - - Push buttons - - - SW[7:1] 0.1 Rev 0.8 | Page 2/31 www.hoperf.com CMT2157AW Abbreviations Abbreviations used in this data sheet are described below AN Application Notes OBW Occupied Bandwidth BOM Bill of Materials OOK On-Off Keying BSC Basic Spacing between Centers PA Power Amplifier BW Bandwidth PC Personal Computer DC Direct Current PCB Printed Circuit Board EEPROM Electrically Erasable Programmable Read-Only PLL Phase Lock Loop Memory PN Phase Noise ESD Electro-Static Discharge RBW Resolution Bandwidth ESR Equivalent Series Resistance RCLK Reference Clock FSK Frequency Shift Keying RF Radio Frequency GFSK Gauss Frequency Shift Keying RFPDK RF Product Development Kit GUI Graphical User Interface RoHS Restriction of Hazardous Substances IC Integrated Circuit Rx Receiving, Receiver LDO Low Drop-Out SOT Small-Outline Transistor Max Maximum TBD To Be Determined MCU Microcontroller Unit Tx Transmission, Transmitter Min Minimum Typ Typical MOQ Minimum Order Quantity XO/XOSC Crystal Oscillator NP0 Negative-Positive-Zero XTAL Crystal Rev 0.8 | Page 3/31 www.hoperf.com CMT2157AW Table of Contents 1. Electrical Characteristics ............................................................................................................................................ 5 1.1 Recommended Operating Conditions ................................................................................................................... 5 1.2 Absolute Maximum Ratings................................................................................................................................... 5 1.3 Transmitter Specifications ..................................................................................................................................... 6 1.4 Crystal Oscillator ................................................................................................................................................... 7 2. Pin Descriptions .......................................................................................................................................................... 8 3. Typical Performance Characteristics ......................................................................................................................... 9 4. Typical Application Schematics ............................................................................................................................... 10 4.1 Low-Cost Application Schematic ......................................................................................................................... 10 4.2 FCC/ETSI Compliant Application Schematic....................................................................................................... 11 5. Functional Descriptions ............................................................................................................................................ 12 5.1 Overview ............................................................................................................................................................. 12 5.2 Modulation, Frequency, Deviation and Symbol Rate .......................................................................................... 12 5.3 Embedded EEPROM and RFPDK ...................................................................................................................... 13 5.4 Power Amplifier ................................................................................................................................................... 15 5.5 PA Ramping ........................................................................................................................................................ 15 5.6 Working States .................................................................................................................................................... 16 5.7 The Encoder........................................................................................................................................................ 17 5.7.1 1920 Packet Structure............................................................................................................................................17 5.7.2 1527 Packet Structure............................................................................................................................................18 5.7.3 2262 Packet Structure............................................................................................................................................19 5.8 ID Study .............................................................................................................................................................. 20 5.9 Button Modes ...................................................................................................................................................... 21 5.9.1 Normal ......................................................................................................................................................................21 5.9.2 Matrix ........................................................................................................................................................................22 5.9.3 Toggle .......................................................................................................................................................................23 5.9.4 PWM .........................................................................................................................................................................23 5.10 LED Driving Capability ........................................................................................................................................ 24 5.11 Low Battery Detection (LBD) ............................................................................................................................... 24 5.12 Crystal Oscillator and RCLK................................................................................................................................ 24 6. Ordering Information ................................................................................................................................................. 26 7. Package Outline......................................................................................................................................................... 27 8. Top Marking ............................................................................................................................................................... 28 8.1 CMT2157AW Top Marking .................................................................................................................................. 28 9. Other Documentations .............................................................................................................................................. 29 10. Document Change List.............................................................................................................................................. 30 11. Contact Information .................................................................................................................................................. 31 Rev 0.8 | Page 4/31 www.hoperf.com CMT2157AW 1. Electrical Characteristics VDD = 3.3 V, TOP = 25 ℃, FRF = 433.92 MHz, output power is +10 dBm terminated in a matched 50 Ω impedance, unless otherwise noted. 1.1 Recommended Operating Conditions Table 2. Recommended Operation Conditions Parameter Symbol Conditions Min Typ Max Unit Operation Voltage Supply VDD 1.8 3.6 V Operation Temperature TOP -40 85 ℃ Supply Voltage Slew Rate 1 mV/us 1.2 Absolute Maximum Ratings Table 3. Absolute Maximum Ratings Parameter Symbol Conditions [1] Min Max Unit Supply Voltage VDD -0.3 3.6 V Interface Voltage VIN -0.3 VDD + 0.3 V Junction Temperature TJ -40 125 ℃ Storage Temperature TSTG -50 150 ℃ Soldering Temperature TSDR 255 ℃ Lasts at least 30 seconds ESD Rating Human Body Model (HBM) Latch-up Current @ 85 ℃ -2 2 kV -100 100 mA Note: [1]. Stresses above those listed as “absolute maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Caution! ESD sensitive device. Precaution should be used when handling the device in order to prevent permanent damage. Rev 0.8 | Page 5/31 www.hoperf.com CMT2157AW 1.3 Transmitter Specifications Table 4. Transmitter Specifications Parameter Symbol [1] Frequency Range Conditions FRF Synthesizer Frequency Resolution Symbol Rate FRES SR (G)FSK Modulation Typ 240 Max Unit 960 MHz FRF ≤ 480 MHz 198 Hz FRF > 480 MHz 397 Hz FSK/GFSK 0.5 100 ksps OOK 0.5 40 ksps 1 200 kHz FDEV Deviation Range Min Bandwidth-Time Product BT Maximum Output Power POUT(Max) GFSK modulation +13 dBm Minimum Output Power POUT(Min) -10 dBm Output Power Step Size PSTEP PA Ramping Time[2] tRAMP Current Consumption @ 433.92 MHz Current Consumption[3] @ 868.35 MHz IDD-433.92 IDD-868.35 Sleep Current ISLEEP Frequency Tune Time tTUNE Phase Noise @ 433.92 MHz Phase Noise @ 868.35 MHz Harmonics Output for [4] 433.92 MHz PN433.92 PN868.35 H2433.92 H3433.92 0.5 - 1 0 OOK, 0 dBm [3] - - dB 1024 us 6 mA OOK, +10 dBm 8.5 mA OOK, +13 dBm 10.2 mA FSK, 0 dBm 10.8 mA FSK, +10 dBm 23.8 mA FSK, +13 dBm 32 mA OOK, 0 dBm 6.1 mA OOK, +10 dBm 9.3 mA OOK, +13 dBm 11.2 mA FSK, 0 dBm 12.3 mA FSK, +10 dBm 26.7 mA FSK, +13 dBm 35.3 mA 20 nA 370 us 100 kHz offset from FRF -80 dBc/Hz 600 kHz offset from FRF -96 dBc/Hz 1.2 MHz offset from FRF -108 dBc/Hz 100 kHz offset from FRF -74 dBc/Hz 600 kHz offset from FRF -90 dBc/Hz 1.2 MHz offset from FRF -102 dBc/Hz 2nd harm @ 867.84 MHz, +13 dBm POUT -52 dBm -57 dBm -68 dBm -52 dBm 60 dB rd 3 harm @ 1301.76 MHz, +13 dBm POUT nd Harmonics Output for H2868.35 2 868.35 MHz [4] H3868.35 3rd harm @ 2605.05 MHz, +13 dBm POUT harm @ 1736.7 MHz, +13 dBm POUT OOK Extinction Ration Notes: [1]. The frequency range is continuous over the specified range. [2]. 0 and 2n us, n = 0 to 10, when set to “0”, the PA output power will ramp to its configured value in the shortest possible time. [3]. The working currents are tested with: 1527 packet format/Normal button mode/ 4 push buttons/Sync ID = 0/No LED. [4]. The harmonics output is measured with the application shown as Figure 10. Rev 0.8 | Page 6/31 www.hoperf.com CMT2157AW 1.4 Crystal Oscillator Table 5. Crystal Oscillator Specifications Parameter [1] Crystal Frequency Symbol Conditions FXTAL Min 26 Crystal Tolerance[2] [3] Load Capacitance Crystal ESR Typ Max Unit 26 26 MHz ±20 CLOAD 12 Rm [4] XTAL Startup Time tXTAL ppm 20 pF 60 Ω 400 us Notes: [1]. The CMT2157AW can directly work with external 26 MHz reference clock input to XTAL pin (a coupling capacitor is required) with amplitude 0.3 to 0.7 Vpp. [2]. This is the total tolerance including (1) initial tolerance, (2) crystal loading, (3) aging, and (4) temperature dependence. The acceptable crystal tolerance depends on RF frequency and channel spacing/bandwidth. [3]. The required crystal load capacitance is integrated on-chip to minimize the number of external components. [4]. This parameter is to a large degree crystal dependent. Rev 0.8 | Page 7/31 www.hoperf.com CMT2157AW 2. Pin Descriptions LED 1 14 XTAL VDD 2 13 CLK GND 3 12 DATA RFO 4 11 K1 K7 5 10 K2 K6 6 9 K3 K5 7 8 K4 Figure 2. CMT2157AW Pin Assignments Table 6. CMT2157AW Pin Descriptions Pin Number Name I/O Descriptions 1 LED O LED driver, active low 2 VDD I Power supply input 3 GND I Ground 4 RFO O Power amplifier output 5 - 11 K[7:1] I Push button 7 to 1 12 DATA IO 13 CLK I 14 XTAL I Data pin to access the embedded EEPROM, internally pulled up to VDD Clock pin to access the embedded EEPROM, internally pulled up to VDD 26 MHz single-ended crystal oscillator input or External 26 MHz reference clock input Rev 0.8 | Page 8/31 www.hoperf.com CMT2157AW 3. Typical Performance Characteristics Phase Noise @ 868.35 MHz Phase Noise @ 433.92 MHz 15 20 13.4dBm @ 433.92 MHz 10 -5 Power (dBm) 0 Power (dBm) 13.0 dBm @ 868.35 MHz 5 -10 -20 -30 -15 -25 -35 -55.9 dBm @ 869.55 MHz -45 -40 -56.8 dBm @ 435.12 MHz -50 -55 -60 -65 432.42 432.72 433.02 433.32 433.62 433.92 434.22 434.52 434.82 435.12 435.42 866.85 867.1 867.35 867.6 867.85 868.1 868.35 868.6 868.85 869.1 869.35 869.6 869.85 Frequency (MHz) Frequency (MHz) Figure 4. Phase Noise, FRF = 433.92 MHz, Figure 3. Phase Noise, FRF = 868.35 MHz, POUT = +13 dBm, RBW = 10 kHz, Un-encoded POUT = +13 dBm, RBW = 10 kHz, Un-encoded FSK vs. GFSK OOK Spectrum 20 20 10 10 0 0 Power (dBm) Power (dBm) FSK -10 -20 -10 GFSK -20 -30 -30 -40 -40 -50 -50 -60 433.62 433.72 433.82 432.92 433.12 433.32 433.52 433.72 433.92 434.12 434.32 434.52 434.72 434.92 433.92 434.02 434.12 434.22 Frequency (MHz) Frequency (MHz) Figure 5. OOK Spectrum, Figure 6. FSK/GFSK Spectrum, POUT = +10 dBm, tRAMP = 32 us SR = 9.6 ksps, FDEV = 15 kHz Spectrum of Various PA Ramping Options POUT vs. VDD 10 16 Power (dBm) -10 14 12 SR = 1.2 ksps Power (dBm) 1024 us 512 us 256 us 128 us 64 us 32 us 0 -20 10 8 13 dBm 6 10 dBm 4 -30 0 dBm 2 -40 0 -2 -50 433.17 433.37 433.57 433.77 433.97 434.17 Frequency (MHz) 434.37 434.57 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 Supply Voltage (V) Figure 7. Spectrum of PA Ramping, Figure 8. Output Power vs. Supply SR = 1.2 ksps, POUT = +10 dBm Voltages, FRF = 433.92 MHz Rev 0.8 | Page 9/31 www.hoperf.com CMT2157AW 4. Typical Application Schematics 4.1 Low-Cost Application Schematic CMT2157AW X1 D1 VDD 1 ANT 2 L1 L2 C2 C0 C1 3 4 SW7 5 SW6 6 SW5 7 VDD CLK GND DATA RFO 14 XTAL LED U1 K1 K7 K2 K6 K3 K5 K4 J1 1 VDD 13 CLK 12 DATA CLK 2 DATA 11 SW1 3 10 SW2 4 9 SW3 8 SW4 Note: Connector J1 is for EEPROM Programming Figure 9. Low-Cost Application Schematic Notes: 1. Connector J1 is a must for the CMT2157AW EEPROM access during development or manufacture phase. 2. The general layout guidelines are listed below. For more design details, please refer to “AN111 CMT215x Schematic and PCB Layout Design Guideline” Use as much continuous ground plane metallization as possible. Use as many grounding vias (especially near to the GND pins) as possible to minimize series parasitic inductance between the ground pour and the GND pins. 3. Avoid using long and/or thin transmission lines to connect the components. Avoid placing the nearby inductors in the same orientation to reduce the coupling between them. Place C0 as close to the CMT2157AW as possible for better filtering. The table below shows the BOM of 433.92/868.35 MHz Low-Cost Application. For the BOM of more applications, please refer to “AN111 CMT215x Schematic and PCB Layout Design Guideline”. Table 7. BOM of 433.92/868.35 MHz Low-Cost Application Value Designator Unit Manufacturer - - CMOSTEK 26 MHz EPSON Descriptions 433.92 MHz U1 CMT2157AW, 240 – 960 MHz (G)FSK/OOK stand-alone transmitter with encoder 868.35 MHz X1 ±20 ppm, SMD32*25 mm crystal C0 ±20%, 0402 X7R, 25 V uF Murata GRM15 C1 ±5%, 0402 NP0, 50 V 82 82 pF Murata GRM15 C2 ±5%, 0402 NP0, 50 V 9.1 3.9 pF Murata GRM15 L1 ±5%, 0603 multi-layer chip inductor 180 100 nH Murata LQG18 L2 ±5%, 0603 multi-layer chip inductor 22 5.1 nH Murata LQG18 D1 D0603, red LED - - - Push buttons - - - SW[7:1] 0.1 Rev 0.8 | Page 10/31 www.hoperf.com CMT2157AW 4.2 FCC/ETSI Compliant Application Schematic CMT2157AW X1 D1 VDD 1 ANT 2 L1 L2 L3 C3 C0 C1 3 4 C2 SW7 5 SW6 6 SW5 7 LED XTAL VDD CLK DATA GND RFO U1 K1 K7 K2 K6 K3 K4 K5 J1 1 VDD 14 13 CLK CLK 12 DATA DATA 11 SW1 10 SW2 9 SW3 8 SW4 2 3 4 Note: Connector J1 is for EEPROM Programming Figure 10. FCC/ETSI Compliant Application Schematic Notes: 1. Connector J1 is a must for the CMT2157AW EEPROM access during development or manufacture phase. 2. The general layout guidelines are listed below. For more design details, please refer to “AN111 CMT215x Schematic and PCB Layout Design Guideline”. Use as much continuous ground plane metallization as possible. Use as many grounding vias (especially near to the GND pins) as possible to minimize series parasitic inductance between the ground pour and the GND pins. 3. Avoid using long and/or thin transmission lines to connect the components. Avoid placing the nearby inductors in the same orientation to reduce the coupling between them. Place C0 as close to the CMT2157AW as possible for better filtering. The table below shows the BOM of 433.92/868.35 MHz FCC/ETSI Compliant Application. For the BOM of more application, please refer to “AN111 CMT215x Schematic and PCB Layout Design Guideline”. Table 8. BOM of 433.92/868.35 MHz FCC/ETSI Compliant Application Value Designator Descriptions Unit 433.92 MHz U1 CMT2157AW, 240 – 960 MHz (G)FSK/OOK stand-alone transmitter with encoder Manufacturer 868.35 MHz - - CMOSTEK 26 MHz EPSON X1 ±20 ppm, SMD32*25 mm crystal C0 ±20%, 0402 X7R, 25 V uF Murata GRM15 C1 ±5%, 0402 NP0, 50 V 68 68 pF Murata GRM15 C2 ±5%, 0402 NP0, 50 V 15 10 pF Murata GRM15 C3 ±5%, 0402 NP0, 50 V 15 6.8 pF Murata GRM15 L1 ±5%, 0603 multi-layer chip inductor 180 100 nH Murata LQG18 L2 ±5%, 0603 multi-layer chip inductor 36 5.6 nH Murata LQG18 L3 ±5%, 0603 multi-layer chip inductor 18 6.8 nH Murata LQG18 D1 D0603, red LED - - - Push buttons - - - SW[7:0] 0.1 Rev 0.8 | Page 11/31 www.hoperf.com CMT2157AW 5. Functional Descriptions VDD LDOs GND POR Bandgap XOSC XTAL LED Driver LED PA RFO VCO PFD/CP Loop Filter Frac-N DIV Encoder K[7:1] Modulator EEPROM Ramp-control K0 K0/DATA CLK Interface & Control Logics Figure 11. CMT2157AW Functional Block Diagram 5.1 Overview The CMT2157AW is a true single-chip, highly flexible, high performance, OOK RF transmitter with embedded data encoder ideal for 240 to 960 MHz wireless applications. It is part of the CMOSTEK NextGenRFTM family, which includes a complete line of transmitters, receivers and transceivers. The device integrates a data encoder that is not only compatible with the most common used encoding format of 1527 and 2262, but also a more efficient, flexible and powerful format of 1920 designed by CMOSTEK. Up to 7 configurable push buttons are supported in multiple button modes. The device is optimized for the low system cost, low power consumption, battery powered application with its highly integrated and low power design. The functional block diagram of the CMT2157AW is shown in figure above. The CMT2157AW is based on direct synthesis of the RF frequency by means of a fully integrated low-noise fractional-N frequency synthesizer. It uses a 1-pin crystal oscillator circuit with the required crystal load capacitance integrated on-chip to minimize the number of external components. Every analog block is calibrated on each Power-on Reset (POR) to an internal reference voltage source. The calibration can help the chip to finely work under different temperatures and supply voltages. The transmission is triggered by pressing the push button(s). The data is modulated and sent out by a highly efficient PA which output power can be configured from -10 to +13 dBm in 1 dB step size. RF Frequency, PA output power and other product features can be programmed into the embedded EEPROM by the RFPDK and USB Programmer. This saves the cost and simplifies the product development and manufacturing effort. Alternatively, in stock product of 868.35 MHz is available for immediate demands with no need of EEPROM programming. The CMT2157AW operates from 1.8 to 3.6 V so that it can finely work with most batteries to their useful power limits. It only consumes 26.7 mA when transmitting +10 dBm FSK signal at 868.35 MHz under 3.3 V supply voltage. 5.2 Modulation, Frequency, Deviation and Symbol Rate The CMT2157AW supports GFSK/FSK modulation with the symbol rate up to 100 ksps, as well as OOK modulation with the symbol rate up to 40 ksps. The supported deviation of the (G)FSK modulation ranges from 1 to 200 kHz. It continuously covers the frequency range from 240 to 960 MHz, including the license free ISM frequency band around 315 MHz, 433.92 MHz, 868.35 MHz and 915 MHz. The device contains a high spectrum purity low power fractional-N frequency synthesizer with output frequency resolution better than 198 Hz when the frequency is less than 480 MHz, and is about 397 Hz when the frequency is larger than 480 MHz. See Table 9 for the modulation, frequency, deviation and symbol rate specifications. Rev 0.8 | Page 12/31 www.hoperf.com CMT2157AW Table 9. Modulation, Frequency, Deviation and Symbol Rate Parameter Value Unit Modulation (G)FSK/OOK - Frequency 240 to 960 MHz Deviation 1 to 200 kHz 198 Hz Frequency Resolution (FRF ≤ 480 MHz) Frequency Resolution (FRF > 480 MHz) 397 Hz Symbol Rate (FSK/GFSK) 0.5 to 100 ksps Symbol Rate (OOK) 0.5 to 40 ksps 5.3 Embedded EEPROM and RFPDK The RFPDK (RF Products Development Kit) is a very user-friendly software tool delivered for the user configuring the CMT2157AW in the most intuitional way. The user only needs to fill in/select the proper value of each parameter and click the “Burn” button to complete the chip configuration. No register access and control is required in the application program. See figure below for the accessing of the EEPROM and Table 10 for the summary of all the configurable parameters of the CMT2157AW on the RFPDK. CMT2157AW RFPDK EEPROM CLK Interface DATA CMOSTEK USB Programmer Figure 12. Accessing Embedded EEPROM For more details of the CMOSTEK USB Programmer and the RFPDK, please refer to “AN113 CMT2150A/2250(1)A One-Way RF Link Development Kits User’s Guide”. For the detail of CMT2157AW configurations with the RFPDK, please refer to “AN142 CMT2157A Configuration Guideline”. Table 10. Configurable Parameters in RFPDK Category Parameters Descriptions Default To input a desired transmitting radio frequency in Frequency the range from 240 to 960 MHz. The step size is 868.35 MHz 0.001 MHz. Modulation The option is FSK or GFSK and OOK. FSK To select a proper transmitting output power from RF Settings Tx Power -10 dBm to +14 dBm, 1 dBm margin is given +13 dBm above +13 dBm. Xtal Cload On-chip XOSC load capacitance options: from 10 to 22 pF. 15.00 pF To determines the symbol rate of the transmitted Symbol Rate data: from 0.5 to 100 ksps in (G)FSK mode and 0.5 to 40 ksps in OOK mode. Rev 0.8 | Page 13/31 2.4 Mode Basic Advanced Basic Advanced Basic Advanced Basic Advanced Basic Advanced www.hoperf.com CMT2157AW Category Parameters Deviation PA Ramping LED Driving Capability Descriptions The FSK frequency deviation. The range is from 1 to 200 kHz. To control PA output power ramp up/down time, options are 0 and 2n us (n from 0 to 10). This defines the driving current of the LED pin. The options are: Disable, 5, 10, 15 or 20 mA. Default 35 kHz Mode Basic Advanced 0 us Advanced 5 mA Advanced 2.4 V Advanced This defines the Low Battery Detection threshold. LBD Threshold The options are: Disable, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7 or 2.8 V. To select whether the frequency “Fo + Fdev” Data Representation represent data 0 or 1. The options are: 0: F-low 0: F-high 1: F-low, or 1: F-high Advanced 0: F-low 1: F-high. Select the packet encoding format, the options Encoder are: 1920, 1527 and 2262. See Table 13, Table 14 and Table 15 for the configurable parameters 1527 Basic Advanced in each packet. This tells the device how many symbols are used to construct a single bit in the 1920 mode. The Bit Format options are: 3, 4, 5 or 6 sym/bit. The Bit Format is 3 fixed at 4 sym/bit in 1527 mode and 8 sym/bit in Encoder 2262 mode. It is only available in 1920 mode. Settings This defines the minimum number of packet(s) Number of Packets Basic Advanced being transmitted during each button pressing action. It also defines the number of packet(s) 1 Advanced consecutive transmitted packets. The unit is in 0 symbols of Basic symbol, the range is from 0 to 255 symbols of zero Advanced being transmitted during each periodic transmission. The range is from 1 to 256. This defines the time interval amount two Packet Interval zero. Select the button encoding mode, the options are: Normal, Matrix, Toggle and PWM. For 1920 Button Mode and 1527 format, all these button modes are Normal supported; For 2262 format, only Normal button Basic Advanced mode is supported. On/Off Button(s) Push Button Settings Select the numbers of on/off button for Toggle and PWM button modes, the options are: Single Single or Separated. Basic Advanced This option is only available in Normal Button Number of Mode, and Encoder is set to 1920 and 1527. It Button(s) defines the number of activated button(s) to be 4 Basic Advanced used in the application. The range is from 1 to 7. Allow the user to select whether or not to inverse Data Inversion the transmitted data bits values in the Normal and No Advanced Off Advanced Toggle Button Mode. The options are: No or Yes. Periodic Transmission Turn on/off the periodic transmission mode of the device. The options are: On or Off. Rev 0.8 | Page 14/31 www.hoperf.com CMT2157AW Category Parameters Descriptions Default Mode 1.000 s Advanced Off Advanced 5s Advanced Pin 11 (K1) Advanced This parameter is only available when Periodic Transmission is turned on. It defines the periodic Periodic Time time for transmitting a fixed set of data. The range is from 2 to 7683.512 s, accurate to 3 decimal points. It is only available when Periodic Transmission is on. Turn on/off the Sync ID study function, the ID Study options are: On or Off. The ID Study is only supported in 1920 and 1527 mode. This parameter is only available when ID Study is Study Trigger Time turned on. It defines the time from the instance of pressing the study button to the instance at which the device starts to transmit the study packets. The range is from 1 to 15 second(s). Study Settings This parameter is only available when ID Study is turned on. It defines which button is used to Study Button trigger the transmission of the study packets. The options are the current buttons used in the Push Button Settings. This parameter is only available when ID Study is Study Power turned on. It defines the PA power when the device is transmitting the study packets. The -6 dBm Basic Advanced range is from –10 to +14 dBm. 5.4 Power Amplifier A highly efficient single-ended Power Amplifier (PA) is integrated in the CMT2157AW to transmit the modulated signal out. Depending on the application, the user can design a matching network for the PA to exhibit optimum efficiency at the desired output power for a wide range of antennas, such as loop or monopole antenna. Typical application schematics and the required BOM are shown in “Chapter 4 Typical Application Schematic”. For the schematic, layout guideline and the other detailed information please refer to “AN111 CMT215x Schematic and PCB Layout Design Guideline”. The output power of the PA can be configured by the user within the range from -10 dBm to +13 dBm in 1 dB step size using the CMOSTEK USB Programmer and RFPDK. 5.5 PA Ramping When the PA is switched on or off quickly, its changing input impedance momentarily disturbs the VCO output frequency. This phenomenon is called VCO pulling, and it manifests as spectral splatter or spurs in the output spectrum around the desired carrier frequency. By gradually ramping the PA on and off, PA transient spurs are minimized. The CMT2157AW has built-in PA ramping configurability with options of 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 and 1024 us, as shown in Figure 13. When the option is set to “0”, the PA output power will ramp up to its configured value in the shortest possible time. The ramp down time is identical to the ramp up time in the same configuration. CMOSTEK recommends that the maximum symbol rate should be no higher than 1/2 of the PA ramping “rate”, as shown in the formula below: SRMax ≤ 0.5 * ( 1 tRAMP Rev 0.8 | Page 15/31 ) www.hoperf.com CMT2157AW In which the PA ramping “rate” is given by (1/tRAMP). In other words, by knowing the maximum symbol rate in the application, the PA ramping time can be calculated by: tRAMP ≤ 0.5 * ( 1 ) SRMAX The user can select one of the values of the tRAMP in the available options that meet the above requirement. If somehow the tRAMP is set to be longer than “0.5 * (1/SRMax)”, it will possibly bring additional challenges to the OOK demodulation of the Rx RFO Amplitude device. For more detail of calculating tRAMP, please refer to “AN142 CMT2157A Configuration Guideline”. 0 us 1 us 2 us 4 us 8 us 512 us 1024 us Data Time Logic 1 Logic 0 Time Figure 13. PA Ramping Time 5.6 Working States The CMT2157AW has following 4 different working states: SLEEP, XO-STARTUP, TUNE and TRANSMIT. The device stays in the SLEEP state when no transmission is performed. Once the button(s) is/are pressed, the device goes through the sequence of SLEEP XO-STARTUP TUNE TRANSMIT to transmit the data. After the transmission the device goes back to the SLEEP state. When the device works in the periodic transmission mode, the device periodically wakes up from the SLEEP state, goes the same sequence, performs the transmission and goes back to the SLEEP state. All the details of push button(s) function and periodic transmission can be referred to “AN142 CMT2157A Configuration Guideline”. SLEEP When the CMT2157AW is in the SLEEP state, all the internal blocks are turned off and the current consumption is minimized to 20 nA typically. XO-STARTUP Once the CMT2157AW received the valid control signal, it will go into the XO-STARTUP state, and the internal XO starts to work. The user has to wait for the tXTAL to allow the XO to get stable. The tXTAL is to a large degree crystal dependent. A typical value of tXTAL is provided in the Table 11. TUNE The frequency synthesizer will tune the CMT2157AW to the desired frequency in the time tTUNE. The PA can be turned on to transmit the data generated by the embedded encoder only after the TUNE state is done. TRANSMIT The CMT2157AW starts to modulate and transmit the data. The data packets being transmitted are generated by the embedded encoder, and they are determined by the encoder selected, the button mode and the button being pressed. Rev 0.8 | Page 16/31 www.hoperf.com CMT2157AW Table 11. Main Timing Spec in Different Working States Parameter XTAL Startup Time Symbol [1] Time to Tune to Desired Frequency[2] Min Typ Max Unit tXTAL 400 us tTUNE 370 us Notes: [1]. This parameter is to a large degree crystal dependent. [2]. From XO stable to ready to transmit. 5.7 The Encoder The device supports 3 types of encoding formats: 1920, 1527 and 2262. The packets of these 3 modes have different structures which will be introduced in the below sub-sections. The table below summarizes the major features of the 3 encoding formats. Table 12. Feature Summary of the 3 Encoding Formats Bit Format Sync ID Length Data Length (sym/bit) (bits) (bits) 1920 3/4/5/6 1 – 32 1–7 Support Support All 1527 4 20 1–7 NA Support All 2262 8 6 – 11 1–6 NA Not Support Normal Mode Format CRC ID Study Button Modes[1] Note: [1]. Button Modes include Normal Mode, Matrix Mode, Toggle Mode and PWM Mode. All the details of these 3 types of encoding formats are given in the document “AN142 CMT2157A Configuration Guideline”. The following sections only give the abstracts of these formats. In the below explanations, some elements in the packet are measured in the unit of “symbol”, while some of them are measured in the unit of “bit”. For those which have the unit of “bit”, one “bit” is constructed (encoded) by several “symbols”. In the figures, “SYM” represents the word “symbol”. 5.7.1 1920 Packet Structure Two types of packet structures are supported for 1920 format: Normal Packet and Study Packet. The following configurable parameters are shared by the two structures. Table 13. Configurable Parameters in 1920 Packet Parameter Preamble Address (Sync ID) Length Address (Sync ID) Value Descriptions Default The size of the valid preamble, the options are: None or 16-symbol. The range of the Sync ID Length is from 1 to 32 bits. The value of the Sync ID has the range from 0 to 2Length-1. Mode Basic None Advanced Basic 32-bit Advanced Basic 0 Advanced Normal Packet The normal packet is used to control the data pins of the CMOSTEK receiver CMT2250AW or PWM output of the CMT2251AW. It contains a 16-symbol Preamble, a 32-symbol Head_N (which indicates that the current packet is a normal packet rather than a study packet), a Sync ID, a Configurable Data Field and an 8-symbol CRC. Rev 0.8 | Page 17/31 www.hoperf.com CMT2157AW Head_N 32 symbols Preamble 16 symbols D0 1 bit Address (Sync ID) configurable 1-32 bits D1 1 bit D2 1 bit D3 1 bit CRC 8 symbols Figure 14. 1920 Normal Packet Structure Study Packet The study packet is used for the receiver to learn the Sync ID from the CMT2157AW in order to pair the two devices. It contains an optional Preamble, a 32-symbol Head_S, a Sync ID and an 8-symbol CRC. Preamble (Optional) 16-symbol Address (Sync ID) configurable 1-32 bits Head_S 32-symbol CRC 8-symbol Figure 15. 1920 Study Packet Structure Bit Format In 1920 packet, a single bit can be constructed (encoded) by 3, 4, 5 or 6 symbols. The user can select the desired value of the “Bit Format” parameter on the RFPDK. Please note that only the Sync ID field and the D0, D1, D2, D3, D4, D5, D6 have the unit of “bit”. 1 SYM 2 SYM 2 SYM 1 SYM 3 Symbols/Bit Bit 1 Bit 0 3 SYM 1 SYM 1 SYM 3 SYM 4 Symbols/Bit Bit 1 Bit 0 2 SYM 3 SYM 3 SYM 2 SYM 5 Symbols/Bit Bit 1 1 SYM 1 SYM Bit 0 2 SYM 2 SYM 1 SYM 1 SYM 1 SYM 3 SYM 6 Symbols/Bit Bit 1 Bit 0 Figure 16. 1920 Bit Format Options 5.7.2 1527 Packet Structure Two types of packet structures are supported for 1527 format: Normal Packet and Study Packet. The following configurable parameter is shared by the two structures. Table 14. Configurable Parameters in 1527 Packet Parameter Address (Sync ID) Value Descriptions Default 20 The range of the Sync ID value is from 0 to 2 -1. This is because the Sync ID Length is fixed at 20 for 1527. 0 Mode Basic Advanced In the traditional 1527 format, 8 OSC clocks are equal to 1 LCK, 4 LCK are equal to 1 symbol. By using the CMT2250AW pairing with CMT2157AW, the user does not need to adjust the OSC to determine the symbol rate, because the symbol rate is directly programmed. The Bit Format is fixed at 4 symbols (16 LCK) per bit. Rev 0.8 | Page 18/31 www.hoperf.com CMT2157AW Normal Packet The traditional 1527 packet contains a 32-symbol Sync, a 20-bit Address (Sync ID) and 4-bit Data. CMOSTEK has defined a 1527 Study Packet to support the ID study in 1527 mode. The traditional packet introduced here is called the “Normal Packet”. Sync 32 symbols D1 1 bit D0 1 bit Address (Sync ID) configurable 20 bits D2 1 bit D3 1 bit Figure 17. 1527 Normal Packet Structure Study Packet The 1527 Study packet contains a 32-symbol Head_S and a 20-bit Address (Sync ID), as shown below. Head_S 32-symbol Address (Sync ID) 20 bits Figure 18. 1527 Study Packet Structure Bit Format In 1527 packet, a single bit is constructed by 4 symbols, as shown below. The user can select the desired value of the “Bit Format” parameter on the RFPDK. Please note that only the Sync ID field and the D0, D1, D2, D3, D4, D5, D6 field have the unit of “bit”. 3 SYM 1 SYM 1 SYM 3 SYM Bit 0 Bit 1 Figure 19. 1527 Bit Format Options 5.7.3 2262 Packet Structure ID Study is not supported in 2262 mode. Only one packet structure is supported. Table 15. Configurable Parameters in 2262 Packet Parameter Descriptions Default Mode This is the range of the Sync ID Length. The range is from Address (Sync ID) 6 to 11 bits. This parameter also defines the number of Length data bits, because the total number of Sync ID and Data 8-bit Basic Advanced bits is fixed at 12. Address (Sync ID) Value The value of each bit of the Sync ID can only be represented by 0, 1 or f. 00000000 Basic Advanced In the traditional 2262 format, 4 OSC clocks (1 OSC clock cycle is notated as 1 α) are equal to 1 symbol. By using the CMOSTEK products, the user does not need to adjust the OSC to define the symbol rate, because the symbol rate is directly programmed. The Bit Format is fixed at 8 symbols per bit. Normal Packet The traditional 2262 packet contains an Address (Sync ID), a Data, and a 32-symbol Sync. Rev 0.8 | Page 19/31 www.hoperf.com CMT2157AW Address (Sync ID) configurable 8-11 bits Sync 32 symbols Data 4-1 bit(s) Figure 20. 2262 Packet Structure Bit Format In 2262 packet, a single bit is constructed by 8 symbols, as shown below. Please note that only the Address (Sync ID) field and the Data field have the unit of “bit”. In the below diagram, 1 OSC clock cycle is notated as 1 α referring to the original 2262 timing descriptions. 1 SYM (4 α) 3 SYM (12 α) 3 SYM (12 α) 1 SYM (4 α) 3 SYM (12 α) 1 SYM (4 α) Bit 1 1 SYM (4 α) 3 SYM (12 α) 1 SYM (4 α) Bit 0 3 SYM (12 α) 3 SYM (12 α) 1 SYM (4 α) Bit f Figure 21. 2262 Bit Format Options 5.8 ID Study The ID Study function, which is supported in 1920 and 1527 modes, allows the receiver to study the Sync ID sent by the CMT2157AW. Since then, the receivers Sync ID is identical to that of the CMT2157AW and therefore two devices are paired. The lengths of the Sync ID are different in the different packet formats. In 1920 format, it is from 1 to 32 bits. In 1527 format, it is fixed at 20 bits. The ID Study is initialized by the CMT2157AW. It is done by executing the following steps. An example of CMT2157AW paring with CMT2250/51AW is given below. 1. Press the Study Button on the CMT2157AW and hold it over the time defined by the “Study Trigger Time”. 2. CMT2157AW starts to transmit the Study Packets, wait 1-2 seconds then release the Study Button. 3. Try to press a certain button on the CMT2157AW to check if the CMT2250/51AW react correctly. The figure below shows the timing characteristic after pressing down a study button. The Study Power is always independently configure from the TX Power. In this example, the Study Power is set smaller than the TX Power. One Normal Packet Packet Interval TX Power = 0 dBm One Study Packet Packet Interval Study Power = -6 dBm time Study Time (Default is 5 s) Study Button Pressed Study Button Released Figure 22. Timing of Study Button Pressing Event More information about the ID Study can be found in the document “AN142 CMT2157A Configuration Guideline”. Rev 0.8 | Page 20/31 www.hoperf.com CMT2157AW 5.9 Button Modes The button modes define the functions of the input pins K1 – K7. The CMT2157AW supports 4 different button modes: Normal, Matrix, Toggle and PWM, which are configured on the RFPDK. The following sections give the abstract of each button mode. All the details of the button modes are given in the document “AN142 CMT2157A Configuration Guideline”. 5.9.1 Normal The Normal Button Mode is supported in 1920, 1527 and 2262 format. In this mode, the buttons are directly mapped to the data field of the packet. Multiple buttons can be pressed at the same time. For 1920 and 1527, the largest number of buttons is 7 which are defined by the parameter “Number of Button(s)”. For 2262, the largest number of buttons is 6, which is determined by the Sync ID Length. The figure below gives an example which 4 push button keys are selected. LED 1 14 XTAL √ XTAL VDD √ VDD 2 13 CLK √ CLK GND √ GND 3 12 K0 × NC RFO √ RFO 4 11 K1 √ D0 LED √ NC × K7 5 10 K2 √ D1 NC × K6 6 9 K3 √ D2 NC × K5 7 8 K4 √ D3 Figure 23. Normal Button Mode In normal button mode, the number of button(s) is used to determines the number of data bits in a packet. The table below shows when 4 buttons are used and the pins K1 – K4 are mapped to the data D0 – D3, “1” in the Push Buttons section means the corresponding button(s) is/are pressed, while the “1” in the Data Bits section means logic “1” to be transmitted. Table 16. Mapping from K1-K4 to D0-D3 in Normal Button Mode Push Buttons The Data Bits K1 K2 K3 K4 D0 D1 D2 D3 1 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 1 1 0 0 1 1 0 0 0 0 1 0 0 0 1 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 1 1 0 1 1 1 0 0 0 0 1 0 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 1 1 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 1 1 1 0 1 1 0 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 Rev 0.8 | Page 21/31 www.hoperf.com CMT2157AW 5.9.2 Matrix The Matrix Button Mode is supported in 1920 and 1527 format. In the Matrix Button Mode, the number of buttons is fixed at 5. On the RFPDK, it can be seen that the 5 buttons are assigned to pin 11 (K1) – pin 7 (K5). In this mode, at most two buttons can be pressed at the same time. The figure below gives an example of Matrix mode push button arrangement. LED 1 14 XTAL √ XTAL VDD √ VDD 2 13 CLK √ CLK GND √ GND 3 12 K0 × NC RFO √ RFO 4 11 K1 √ B0 LED √ NC × K7 5 10 K2 √ B1 NC × K6 6 9 K3 √ B2 B4 √ K5 7 8 K4 √ B3 Figure 24. Matrix Button Mode The user is able to use the 5 buttons K1(B0) – K5(B4) to generate different combinations of the data D0 – D3 to be transmitted. The number of data bits to be transmitted is fixed at 4. The table below shows the matrix. For the K1 – K5 buttons, “1” in the Push Buttons section means the corresponding button(s) is/are pressed down, while the “1” in the Data Bits section means a logic “1” to be transmitted.. Table 17. Mapping from K1-K5 to D0-D3 in Matrix Button Mode Push Buttons K1 K2 K3 The Data Bits K4 K5 D0 D1 D2 D3 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 1 0 1 0 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 1 1 0 1 0 0 1 0 0 0 0 1 1 0 0 0 1 1 0 0 1 0 1 1 0 0 0 1 0 1 0 1 0 1 0 1 1 0 1 0 1 0 0 1 0 0 1 1 0 0 1 1 0 1 0 1 1 0 0 1 0 1 0 1 1 1 0 0 0 1 1 1 1 1 1 Rev 0.8 | Page 22/31 www.hoperf.com CMT2157AW 5.9.3 Toggle The Toggle Button Mode is supported in 1920 and 1527. In this mode, 5 or 6 buttons are used. Four buttons directly mapped to the data D0 – D3 are used to control the data. Besides, a single button or two separated buttons used to turn on/off the data can be chosen by the parameter “On/Off Button(s)”. In this mode, only one button can be pressed at the same time. Pin 12 (K0) and Pin 5 (K7) are never used in this mode. The figure below gives examples of the pin functions in Toggle mode. LED 1 14 XTAL √ XTAL VDD √ VDD 2 13 CLK GND √ GND 3 12 RFO √ RFO 4 LED √ LED 1 14 XTAL √ XTAL √ CLK VDD √ VDD 2 13 CLK √ CLK K0 × NC GND √ GND 3 12 K0 × NC 11 K1 √ ON/OFF RFO √ RFO 4 11 K1 √ ON LED √ NC × K7 5 10 K2 × NC NC × K7 5 10 K2 √ OFF D3 √ K6 6 9 K3 √ D0 D3 √ K6 6 9 K3 √ D0 D2 √ K5 7 8 K4 √ D1 D2 √ K5 7 8 K4 √ D1 Figure 25. Toggle Button Mode with Single (left) and Separated (right) ON/OFF Button(s) For the 4 data buttons mapped to D0 – D3, every time a button is pressed, the generated data bit toggles. For example, if the default value of D1 is 0, press K4 down, the D1 is set to 1 in the current transmission, release the K4 and press it down again, the D1 is set to 0 in the current transmission, and so on. This is what it means by “Toggle”. See the table below for the examples of toggle button mode Table 18. Examples of the Toggle Button Mode On/Off Button(s) Pressed Button (Times) D0 D1 D2 D3 Press K4 (D1) – 1 Time 0 1 0 0 Press K4 (D1) – 2nd Time 0 0 0 0 0 1 0 0 Press K1 – 1 Time (On) 1 1 1 1 Press K1 – 2nd Time (Off) 0 0 0 0 Press K1 – 3rd Time (On) 1 1 1 1 Press K4 (D1) – 1 Time 0 1 0 0 Press K4 (D1) – 2nd Time 0 0 0 0 Press K4 (D1) – 3 Time 0 1 0 0 Press K1 (On) 1 1 1 1 Press K2 (Off) 0 0 0 0 Press K1 (On) 1 1 1 1 st Single (K1 is On/Off) rd Press K4 (D1) – 3 Time st st Separated (K1 is On K2 is Off) rd 5.9.4 PWM The PWM Button Mode is only supported for 1920 and 1527 encoding format. In this mode, 2 buttons are used to send out commands to increase or decrease the duty ratio of the PWM output of the CMT2251AW. A single on/off button, or two separated on/off buttons can be chosen by the parameter “On/Off Button(s)”. The “On” command sets the PWM output of the CMT2251AW to 100% of duty ratio, while the “Off” command sets the PWM output to 0% of duty ratio. In this mode, only one button can be pressed at the same time. Pin 12 (K0), Pin 9 (K3), Pin 6 (K6) and Pin 5 (K7) are never used in this mode. The commands of On, Off, Increase and Decrease are represented by D0 – D3. The figure below gives examples of the pin Rev 0.8 | Page 23/31 www.hoperf.com CMT2157AW functions in PWM mode. LED 1 14 XTAL √ XTAL √ CLK VDD √ VDD 2 13 CLK √ CLK K0 × NC GND √ GND 3 12 K0 × NC 11 K1 √ ON/OFF RFO √ RFO 4 11 K1 √ ON/OFF LED 1 14 XTAL √ XTAL VDD √ VDD 2 13 CLK GND √ GND 3 12 RFO √ RFO 4 LED √ LED √ NC × K7 5 10 K2 × NC NC × K7 5 10 K2 √ OFF NC × K6 6 9 K3 × NC NC × K6 6 9 K3 × NC DEC √ K5 7 8 K4 √ INC DEC √ K5 7 8 K4 √ INC Figure 26. PWM Button Mode with Single (left) and Separated (right) ON/OFF Button(s) If K1 is used as the On/Off Button, press it down once, the “On” command is transmitted, release and press it down again, the “Off” command is transmitted, and so on. In this case, K1 is a “Toggle” button. If the K1 is used as the On Button and K2 is used as the Off Button, pressing K1, the “On” command is transmitted; pressing K2, the “Off” command is transmitted. 5.10 LED Driving Capability This defines the maximum current driving capacity on the LED pin. Once the LED pin is enabled, it will light up or flash to indicate two events: When the chip is transmitting data, the LED will light up until the transmission is finished to notify the user the chip is working, when the LBD is disabled, or LBD is enabled but there is no low battery detected. When the LBD is enabled and there is valid low battery detection on the button(s) pressing, the LED will flash at least 5 times at the frequency of 6 Hz to notify the user the battery is running out. 5.11 Low Battery Detection (LBD) This defines the Low Battery Detection threshold. Once the LBD is enabled, the chip will automatically check the battery status before each transmission. Once the chip finds that the battery output is less than the detection threshold, the LED will flash at least 5 times at the frequency of 6 Hz to notify the user. Once the LED flashes, the performance of the transmission is not guaranteed. The user should change the batteries to new ones. 5.12 Crystal Oscillator and RCLK The CMT2157AW uses a 1-pin crystal oscillator circuit with the required crystal load capacitance integrated on-chip. Figure 27 shows the configuration of the XTAL circuitry and the crystal model. The recommended specification for the crystal is 26 MHz with ±20 ppm, ESR (Rm) < 60 Ω, load capacitance CLOAD ranging from 12 to 20 pF. To save the external load capacitors, a set of variable load capacitors CL is built inside the CMT2157AW to support the oscillation of the crystal. The value of load capacitors is configurable with the CMOSTEK USB Programmer and RFPDK. To achieve the best performance, the user only needs to input the desired value of the XTAL load capacitance CLOAD of the crystal (can be found in the datasheet of the crystal) to the RFPDK, then finely tune the required XO load capacitance according to the actual XO frequency. Please refer to “AN113 CMT2157A/2250(1)A One-Way RF Link Development Kits User’s Guide” for the method of choosing the right value of CL. Rev 0.8 | Page 24/31 www.hoperf.com CMT2157AW Crystal Model CMT2157AW CMT2157AW Cc XTAL RCLK 26 MHz 0. 3 – 0. 7 Vpp Rm Cm XTAL C0 CL CL Lm Figure 27. XTAL Circuitry and Crystal Model Figure 28. RCLK Circuitry If a 26 MHz RCLK (reference clock) is available in the system, the user can directly use it to drive the CMT2157AW by feeding the clock into the chip via the XTAL pin. This further saves the system cost due to the removal of the crystal. A coupling capacitor is required if the RCLK is used. The recommended amplitude of the RCLK is 0.3 to 0.7 Vpp on the XTAL pin. Also, the user should set the internal load capacitor CL to its minimum value. See Figure 28 for the RCLK circuitry. Rev 0.8 | Page 25/31 www.hoperf.com CMT2157AW 6. Ordering Information Table 19. CMT2157AW Ordering Information Part Number Descriptions Package Package Operating MOQ / Type Option Condition Multiple SOP14 Tape & Reel SOP14 Tube 240 – 960 MHz CMT2157AW-ESR[1] (G)FSK/OOK Stand-Alone Transmitter with Encoder 240 – 960 MHz [1] CMT2157AW-ESB (G)FSK/OOK Stand-Alone Transmitter with Encoder 1.8 to 3.6 V, 2,500 -40 to 85 ℃ 1.8 to 3.6 V, 1,000 -40 to 85 ℃ Note: [1]. “E” stands for extended industrial product grade, which supports the temperature range from -40 to +85 ℃. “S” stands for the package type of SOP14. “R” stands for the tape and reel package option, the minimum order quantity (MOQ) for this option is 2,500 pcs. “B” stands for the tube package option, with the MOQ of 1,000 pcs. The default frequency for CMT2157AW is 868.35 MHz, for the other settings, please refer to the Table 10 of Page 13. Visit www.cmostek.com/products to know more about the product and product line. Contact [email protected] or your local sales representatives for more information. Rev 0.8 | Page 26/31 www.hoperf.com CMT2157AW 7. Package Outline D A3 h A2 A 0.25 c θ A1 L L1 E1 b E e Figure 29. 14-Pin SOP Package Table 20. 14-Pin SOP Package Dimensions Size (millimeters) Symbol Min Typ Max A - - 1.75 A1 0.05 - 0.225 A2 1.30 1.40 1.50 A3 0.60 0.65 0.70 b 0.39 - 0.48 C 0.21 - 0.26 D 8.45 8.65 8.85 E 5.80 6.00 6.20 E1 3.70 3.90 4.10 e 1.27 BSC h 0.25 - 0.50 L 0.30 - 0.60 L1 θ 1.05 BSC 0 - Rev 0.8 | Page 27/31 8° www.hoperf.com CMT2157AW 8. Top Marking 8.1 CMT2157AW Top Marking CMT 2 1 5 7 A Y Y W W ①②③④⑤⑥ Figure 30. CMT2157AW Top Marking Table 21. CMT2157AW Top Marking Explanation Mark Method : Laser Pin 1 Mark : Circle’s diameter = 1 mm Font Size : 0.35 mm, right-justified Line 1 Marking : CMT2157A, represents part number CMT2157AW YYWW is the Date code assigned by the assembly house. YY represents the last two digits of Line 2 Marking : the mold year and WW represents the workweek ①②③④⑤⑥ is the internal tracking number Rev 0.8 | Page 28/31 www.hoperf.com CMT2157AW 9. Other Documentations Table 22. Other Documentations for CMT2157AW Brief AN111 AN142 AN113 AN115 Name Descriptions CMT215x Schematic and PCB Layout Design Guideline CMT2157A/2250(1)A One-Way RF Link Pairing CMT215x and CMT225x design rules, RF matching network and other application layout design related issues. CMT2157A Configuration Guideline Development Kits User’s Guide Details of CMT2150/57AW PCB schematic and layout Details of configuring CMT2157AW features on the RFPDK. User’s Guides for CMT2157AW/2250(1)AW Development Kits, including Evaluation Board and Evaluation Module, CMOSTEK USB Programmer and RFPDK. Provide quick guideline in how to pair the CMT2150/57AW with CMT2250/51AW. Rev 0.8 | Page 29/31 www.hoperf.com CMT2157AW 10. Document Change List Table 23. Document Change List Rev. No. Chapter 0.8 All Description of Changes Initial released version Rev 0.8 | Page 30/31 Date 2015-02-11 www.hoperf.com CMT2157AW 11. Contact Information Hope Microelectronics Co., Ltd Address: 2/F,Building3,Pingshan Private Enterprise science and Technology Park,Xili Town,Nanshan District,Shenzhen,China Tel: +86-755-82973805 Fax: +86-755-82973550 Email: [email protected] [email protected] Website: http://www.hoperf.com http://www.hoperf.cn Copyright. CMOSTEK Microelectronics Co., Ltd. All rights are reserved. The information furnished by CMOSTEK is believed to be accurate and reliable. However, no responsibility is assumed for inaccuracies and specifications within this document are subject to change without notice. The material contained herein is the exclusive property of CMOSTEK and shall not be distributed, reproduced, or disclosed in whole or in part without prior written permission of CMOSTEK. CMOSTEK products are not authorized for use as critical components in life support devices or systems without express written approval of CMOSTEK. The CMOSTEK logo is a registered trademark of CMOSTEK Microelectronics Co., Ltd. All other names are the property of their respective owners. Rev 0.8 | Page 31/31 www.hoperf.com ">
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