MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators General Description The MAX8891/MAX8892 low-dropout (LDO) linear regulators are designed to deliver up to 150mA continuous output current. These regulators achieve a low 120mV dropout for 120mA load current. The MAX8891 only requires an input/output capacitor, hence achieving the smallest PCB area. The MAX8892’s output voltage can be adjusted with an external divider. The MAX8891 is preset to a variety of voltages in the 1.5V to 4.5V range. Designed with a p-channel MOSFET series pass transistor, the MAX8891/MAX8892 maintain very low ground current (40µA). The regulators are designed and optimized to work with low-value, low-cost ceramic capacitors. The MAX8891/ MAX8892 require only 1µF (typ) of output capacitance for stability with any load. When disabled, current consumption drops to below 1µA. These regulators are available in a tiny 5-pin SC70 package. Applications Cellular and Cordless Phones PDA and Palmtop Computers Base Stations Bluetooth Portable Radios and Accessories Wireless LANs Digital Cameras Personal Stereos Portable and Battery-Powered Equipment Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ Space-Saving SC70 Package 65dB PSRR at 10kHz 120mV Dropout at 120mA Load Stable with 1µF Ceramic Capacitor for Any Load Guaranteed 150mA Output Only Need Input and Output Capacitors (MAX8891) Output Voltages: 1.5V, 1.8V, 2.5V, 2.6V, 2.7V, 2.8V, 2.85V, 3V, 3.3V, 4.5V (MAX8891) and Adjustable (MAX8892) ♦ Low 40µA Ground Current ♦ Excellent Load/Line Transient ♦ Overcurrent and Thermal Protection Ordering Information TEMP RANGE PIN-PACKAGE MAX8891EXKxy+T PART* -40°C to +85°C 5 SC70 MAX8891EXKxy/V+T -40°C to +85°C 5 SC70 MAX8892EXK+T -40°C to +85°C 5 SC70 *xy is the output voltage code (see Output Voltage Selector Guide). Other versions between 1.5V and 4.5V are available in 100mV increments. Contact factory for other versions. +Denotes a lead(Pb)-free/RoHS-compliant package. /V denotes an automotive qualified part. Typical Operating Circuits INPUT 2V TO 6V IN ON OFF OUTPUT PRESET 1.5V TO 4.5V MAX8891 CIN = 1μF Output Voltage Selector Guide appears at end of data sheet. OUT SHDN COUT = 1μF GND Pin Configuration TOP VIEW + GND 2 INPUT 2V TO 6V 5 OUT IN 1 MAX8891/ MAX8892 CIN = 1μF ON OFF 4 N.C. (MAX8891) FB (MAX8892) SHDN 3 IN OUT MAX8892 OUTPUT ADJUSTABLE 1.5V TO 4.5V R1 FB SHDN GND COUT = 1μF R2 SC70 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. 19-4537; Rev 1; 12/11 MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators ABSOLUTE MAXIMUM RATINGS IN to GND .................................................................-0.3V to +7V Output Short-Circuit Duration.....................................Continuous OUT, SHDN to GND ....................................-0.3V to (VIN + 0.3V) FB, BP, N.C. to GND ................................-0.3V to (VOUT + 0.3V) Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............0.247W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. PACKAGE THERMAL CHARACTERISTICS (Note 1) SC70 Junction-to-Ambient Thermal Resistance (θJA) .........324°C/W Junction-to-Case Thermal Resistance (θJC) ..............115°C/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. ELECTRICAL CHARACTERISTICS (VIN = VOUT + 0.5V, TA = -40°C to +85°C, unless otherwise noted. CIN = 1µF, COUT = 1µF. Typical values are at TA = +25°C; the MAX8892 is tested with 2.45V output, unless otherwise noted.) (Note 2) PARAMETER Input Voltage Range SYMBOL CONDITIONS VIN Output Voltage Accuracy I OUT Current Limit ILIM TYP 2 I OUT = 100μA to 80mA Maximum Output Current MIN -3 MAX UNITS 6 V +3 % 150 mA I OUT = 90% of nominal value 200 mA VOUT 3V, I OUT = 120mA 120 Dropout Voltage (Note 3) 2.5V VOUT < 3V, I OUT = 120mA 135 180 Ground Current IQ 2V VOUT < 2.5V, I OUT = 120mA I OUT = 0.05mA 40 μA Line Regulation VLNR VIN = (VOUT + 0.5V) to 6V, I OUT = 0.1mA 0.001 %/V Load Regulation VLDR I OUT = 1mA to 80mA 0.003 %/mA Shutdown Supply Current I SHDN VSHDN = 0V Ripple Rejection PSRR Output Noise Voltage (RMS) f = 10kHz, I OUT = 10mA f = 100Hz to 100kHz, ILOAD = 80mA SHDN Logic-Low Level VIN = 2V to 6V SHDN Logic-High Level VIN = 2V to 6V SHDN Input Bias Current VIN = 6V, VSHDN = 0V or 6V TA = +25°C TA = +85°C 0.01 FB Input Bias Current (MAX8892) VIN = 6V, VFB = 1.3V TA = +25°C 0.006 TA = +85°C 0.01 Thermal Shutdown Thermal-Shutdown Hysteresis TA = +25°C 0.003 TA = +85°C 0.05 mV 1 μA dB 65 μV 230 0.4 1.5 V V μA 0.1 μA 160 °C 10 °C Note 2: Limits are 100% tested at TA = +25°C. Limits over operating temperature range are guaranteed by design. Note 3: Dropout is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V. 2 Maxim Integrated MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Typical Operating Characteristics (VIN = VOUT + 0.5V, CIN = 1µF, COUT = 1µF, TA = +25°C, unless otherwise noted.) 1.5 IOUT = 120mA 0.2 0 -0.2 0.5 -0.4 0.0 -0.6 MAX8891/2 toc03 IOUT = 1mA 0.8 0.6 % DEVIATION (%) 2.0 1.0 0.4 % DEVIATION (%) IOUT = 0mA 1.0 MAX8891/2 toc02 2.5 OUTPUT VOLTAGE (V) 0.6 MAX8891/2 toc01 3.0 OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE OUTPUT VOLTAGE ACCURACY vs. LOAD CURRENT OUTPUT VOLTAGE vs. INPUT VOLTAGE 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 3 4 5 6 0 25 140 120 100 80 TA = -40°C 60 100 125 10 35 GROUND PIN CURRENT vs. INPUT VOLTAGE 200 150 100 300 250 200 150 100 IOUT = 0mA 50 20 0 25 50 75 100 125 0 2.0 150 2.2 2.8 3.0 3.2 0 VIN = 3.8V 150 100 75 100 Maxim Integrated 125 150 1000 70 60 40 50 40 30 35 20 ILOAD = 10mA 0 30 50 100 80 10 LOAD CURRENT (mA) 5 PSRR vs. FREQUENCY MAX8891/2 toc08 45 50 0 4 3 90 PSRR (dB) 250 25 2 INPUT VOLTAGE (V) 50 GROUND PIN CURRENT (μA) MAX8891/2 toc07 VIN = 5.5V 0 1 GROUND PIN CURRENT vs. TEMPERATURE GROUND PIN CURRENT vs. LOAD CURRENT 350 200 2.6 OUTPUT (V) LOAD CURRENT (mA) 300 2.4 MAX8891/2 toc09 0 85 350 50 0 60 TEMPERATURE (°C) IOUT = 80mA 40 GROUND PIN CURRENT (μA) -15 -40 150 250 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV)) TA = +85°C MAX8891/2 toc04 TA = +25°C 160 75 DROPOUT VOLTAGE vs. OUTPUT VOLTAGE DROPOUT VOLTAGE vs. LOAD CURRENT 200 180 50 LOAD CURRENT (mA) MAX8891/2 toc06 2 INPUT VOLTAGE (V) GROUND PIN CURRENT (μA) 1 MAX8891/2 toc05 0 -1.0 -40 -15 10 35 TEMPERATURE (°C) 60 85 0.01 0.1 1 10 FREQUENCY (kHz) 3 MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Typical Operating Characteristics (continued) (VIN = VOUT + 0.5V, CIN = 1µF, COUT = 1µF, TA = +25°C, unless otherwise noted.) LOAD TRANSIENT RESPONSE dl/dt = 0.5mA/μs LOAD TRANSIENT RESPONSE dl/dt = 5mA/μs MAX8891/2 toc10 50mA 10mA MAX8891/2 toc11 50mA VIN = 3.5V ILOAD 25mA/div 10mA dl/dt = 0.5mA/μs LOAD TRANSIENT RESPONSE dl/dt = 20mA/μs 10mA MAX8891/2 toc12 50mA VIN = 3.5V ILOAD 25mA/div 10mA dl/dt = 0.5mA/μs VIN = 3.5V 10mA 10mA dl/dt = 20mA/μs VIN 10mV/div VIN 10mV/div VIN 10mV/div VOUT 10mV/div VOUT 10mV/div VOUT 10mV/div 200μs/div 20μs/div 4μs/div STARTUP WAVEFORM SHUTDOWN WAVEFORM LINE TRANSIENT RESPONSE dv/dt = 500mV/μs MAX8891/2 toc13 VIN = 3.5V RLOAD = 30Ω ILOAD 25mA/div MAX8891/2 toc15 MAX8891/2 toc14 VIN = 3.5V RLOAD = 30Ω ON ON VSHDN 2V/div OFF RLOAD = 30Ω 4V VSHDN 2V/div OFF dv/dt = 500mV/μs 4V VIN 500mV/div 3.5V VOUT 500mV/div VOUT 10mV/div VOUT 500mV/div 10μs/div 40μs/div 40μs/div REGION OF STABLE COUT ESR vs. LOAD CURRENT LINE TRANSIENT RESPONSE dv/dt = 200mV/μs MAX8891/2 toc16 MAX8891/2 to17 100 RLOAD = 30Ω 5V dv/dt = 200mV/μs 5V VIN 1V/div VOUT 10mV/div COUT ESR (Ω) 3.5V 10 1 0.1 STABLE REGION 0.01 40μs/div 0 25 50 75 100 125 150 LOAD CURRENT (mA) 4 Maxim Integrated MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Pin Description PIN NAME MAX8891 MAX8892 1 1 IN 2 2 GND FUNCTION Unregulated Input Supply Ground 3 3 SHDN — 4 FB 4 — N.C. Not Internally Connected 5 5 OUT Regulated Output Voltage. Bypass with a capacitor to GND. See the Capacitor Selection and Regulator Stability section for more details. Shutdown. Pull low to disable the regulator. Adjustable Output Feedback Point Detailed Description The MAX8891/MAX8892 are low-dropout, low-quiescent current linear regulators designed for spacerestricted applications. The parts are available with preset output voltages ranging from 1.5V to 4.5V in 100mV increments. These devices can supply loads up to 150mA. As shown in the Functional Diagram, the MAX8891 consists of an innovative bandgap core, error amplifier, p-channel pass transistor, and internal feedback voltage-divider. The MAX8892 allows for adjustable output with an external feedback network. Additional blocks include a current limiter, thermal sensor, and shutdown logic. The 1.225V bandgap reference is connected to the error amplifier’s inverting input. The error amplifier compares this reference with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled low. This allows more current to pass to the output and increases the output voltage. If the feedback voltage is too high, the pass transistor gate is pulled high, allowing less current to pass to the output. The output voltage is fed back through an internal (external for the MAX8892) resistor voltage-divider connected to the OUT pin. Internal P-Channel Pass Transistor The MAX8891/MAX8892 feature a 1Ω (typ) p-channel MOSFET pass transistor. This provides several advantages over similar designs using a PNP pass transistor, including longer battery life. The p-channel MOSFET requires no base drive, which considerably reduces quiescent current. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They also use high base-drive current under Maxim Integrated heavy loads. The MAX8891/MAX8892 do not suffer from these problems and consume only 40µA of quiescent current in light load and 220µA in dropout (see the Typical Operating Characteristics). Output Voltage Selection The MAX8891 is supplied with factory-set output voltages from 1.5V to 4.5V, in 100mV increments (see the Ordering Information). The MAX8892 features a useradjustable output through an external feedback network (see the Typical Operating Circuits). To set the output of the MAX8892, use the following equation: ⎛ VOUT ⎞ R1 = R2 × ⎜ -1 ⎝ VREF ⎟⎠ where R2 is chosen to be less than 240kΩ and VREF = 1.225V. Use 1% or better resistors. Shutdown The MAX8891/MAX8892 feature a low-power shutdown mode that reduces quiescent current less than 1µA. Driving SHDN low disables the voltage reference, error amplifier, gate-drive circuitry, and pass transistor (see the Functional Diagram), and the device output enters a high-impedance state. Connect SHDN to IN for normal operation. Current Limit The MAX8891/MAX8892 include a current limiter, which monitors and controls the pass transistor’s gate voltage, limiting the output current to 200mA. The output can be continuously shorted to ground without damaging the part. 5 MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Thermal-Overload Protection Thermal-overload protection limits total power dissipation in the MAX8891/MAX8892. When the junction temperature exceeds TJ = +160°C, the thermal sensor signals the shutdown logic, turning off the pass transistor and allowing the IC to cool down. The thermal sensor turns the pass transistor on again after the IC’s junction temperature drops by 10°C, resulting in a pulsed output during continuous thermal-overload conditions. Thermal-overload protection is designed to protect the MAX8891/MAX8892 in the event of a fault condition. For continual operation, do not exceed the absolute maximum junction temperature rating of TJ = +150°C. Operating Region and Power Dissipation The MAX8891/MAX8892 maximum power dissipation depends on the thermal resistance of the case and circuit board, the temperature difference between the die junction and ambient, and the rate of airflow. The power dissipation across the device is: P = IOUT (VIN - VOUT) The maximum power dissipation is: PMAX = (TJ - TA)/(θJC + θCA) where TJ - TA is the temperature difference between the MAX8891/MAX8892 die junction and the surrounding air, θJC is the thermal resistance of the package, and θCA is the thermal resistance through the PCB, copper traces, and other materials to the surrounding air. The GND pin of the MAX8891/MAX8892 performs the dual function of providing an electrical connection to ground and channeling heat away. Connect the GND pin to ground using a large pad or ground plane. 6 Applications Information Capacitor Selection and Regulator Stability Use a 1µF capacitor on the MAX8891/MAX8892 input and a 1µF capacitor on the output. Larger input capacitor values and lower ESRs provide better noise rejection and line-transient response. Reduce output noise and improve load-transient response, stability, and powersupply rejection by using large output capacitors. Note that some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. With dielectrics such as Z5U and Y5V, it may be necessary to use a 2.2µF or larger output capacitor to ensure stability at temperatures below -10°C. With X7R or X5R dielectrics, 1µF is sufficient at all operating temperatures. A graph of the region of stable COUT ESR vs. load current is shown in the Typical Operating Characteristics. PSRR and Transient Response The MAX8891/MAX8892 are designed to deliver high PSRR as well as low dropout and low quiescent currents in battery-powered systems. The MAX8891/MAX8892 power-supply rejection is 65dB at 10kHz. When operating from sources other than batteries, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors, and through passive filtering techniques. The Typical Operating Characteristics show the MAX8891/MAX8892 line- and load-transient responses. Dropout Voltage A regulator’s minimum dropout voltage determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the MAX8891/MAX8892 use a p-channel MOSFET pass transistor, their dropout voltage is a function of drain-to-source on-resistance (RDS(ON)) multiplied by the load current (see the Typical Operating Characteristics). Maxim Integrated MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Functional Diagram IN SHDN SHUTDOWN AND POWER-ON CONTROL ERROR AMP MAX8891/ MAX8892 MOS DRIVER WITH ILIMIT P OUT * THERMAL SENSOR FB** 1.225V REFERENCE * GND *MAX8891 ONLY **MAX8892 ONLY Chip Information Output Voltage Selector Guide PART V OUT (V) TOP MARK PROCESS: BiCMOS MAX8891EXK15+T 1.5 ATI Package Information MAX8891EXK18+T 1.8 ATJ MAX8891EXK25+T 2.5 ATL MAX8891EXK26+T 2.6 ATM MAX8891EXK28+T 2.8 ATO For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MAX8891EXK29+T 2.85 ATP MAX8891EXK89+T 2.9 ATV PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. MAX8891EXK30+T 3.0 ATQ 5 SC70 X5+1 21-0076 90-0188 MAX8891EXK31+T 3.1 ATR MAX8891EXK33+T 3.3 ATS MAX8891EXK33/V+T 3.3 AUR MAX8891EXK45+T 4.5 ATU Adjustable ATW MAX8892EXK+T Note: Standard output voltage options, shown in bold, are available. Contact the factory for other output voltages between 1.5V and 4.5V. Minimum order quantity is 15,000 units. Maxim Integrated 7 MAX8891/MAX8892 High PSRR, Low-Dropout, 150mA Linear Regulators Revision History REVISION NUMBER REVISION DATE 0 3/09 1 12/11 DESCRIPTION Initial release PAGES CHANGED — Added the /V option to the Ordering Information table and the Output Voltage Selector Guide; updated the Package Information table 1, 7 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 8 © 2011 Maxim Integrated Products, Inc. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
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