LP3994 50mA CMOS Voltage Regulator with Enable Control General Description Key Specifications The LP3994 regulator provides 1.5V and 1.8V outputs options at up to 50mA load current. The LP3994 provides an accurate output voltage with low quiescent current at full current. Good noise performance is obtained without a noise bypass capacitor. The low quiescent current in operation can be reduced to virtually zero when the device is disabled via a logic signal to the enable input. In conjuction with small space saving capacitors, the small package size of the microSMD devices results in a regulator solution with a very small footprint for any given application. The LP3994 is suitable for general use within the range of portable, battery-powered equipment and voltage options other than 1.5V and 1.8V can be made available. The LP3994 also features short-circuit and thermalshutdown protection. Performance is specified for a -40˚C to 125˚C temperature range. This device is available with output voltages of 1.5V and 1.8V in both microSMD and LLP packages. Other voltages and alternative packages may be made available, please contact your local NSC sales office. n n n n n n n n Input Voltage Range Output Voltage Range Output Current Noise Figure PSRR Fast Startup Output Capacitor Virtually Zero IQ(Disabled) 2.5 to 5.5V 1.5 to 3.3V 50mA 95µVRMS 70dB 10µs 1µF Low ESR 0.001µA Package Tiny 4 Pin micro SMD 1mm by 1mm by 0.6m 6 pin LLP SOT23 footprint Applications n Bluetooth Devices n Battery Powered Devices n Portable Information Appliances Features n n n n n n 4 Pin MicroSMD Package/ 6 Pin LLP No Noise Bypass Capacitor Required Logic Controlled Enable Stable with Low ESR Ceramic Capacitors Fast turn on time Thermal-Overload and Short Circuit Protection Typical Application Circuit 20046501 © 2004 National Semiconductor Corporation DS200465 www.national.com LP3994 50mA CMOS Voltage Regulator with Enable Control August 2004 LP3994 Pin Descriptions Packages micro SMD-4 and LLP-6 Pin No micro SMD Pin No LLP A1 5 B1 B2 A2 Symbol Name and Function VEN Enable Input; Enables the Regulator when ≥ 1.2V Disables the Regulator when ≤ 0.4V 2 GND Common Ground 1 VOUT Voltage output. A 1.0µF Low ESR Capacitor should be connected to this Pin. Connect this output to the load circuit. 6 VIN Voltage Supply Input. A 1.0µF capacitor should be connected at this input. 3 No Connection. Do not connect to any other device pins. 4 No Connection. Do not connect to any other device pins. pad Connect to ground for good thermal operation. Connection Diagrams 20046502 micro SMD-4 Package See NS package number TLA04 20046507 LLP- 6 Package (SOT23 footprint) See NS Package Number LDE06A www.national.com 2 LP3994 Ordering Information For micro SMD Package Output Voltage (V) Grade LP3994 Supplied as 1000 Units, Tape and Reel LP3994 Supplied as 3000 Units, Tape and Reel 1.5 STD LP3994TL-1.5 LP3994TLX-1.5 1.8 STD LP3994TL-1.8 LP3994TLX-1.8 For microSMD Package (Lead Free) Output Voltage (V) Grade LP3994 Supplied as 1000 Units, Tape and Reel LP3994 Supplied as 3000 Units, Tape and Reel 1.5 STD LP3994TL-1.5NOPB LP3994TLX-1.5NOPB 1.8 STD LP3994TL-1.8NOPB LP3994TLX-1.8NOPB For LLP Package Output Voltage (V) Grade LP3994 Supplied as 1000 Units, Tape and Reel LP3994 Supplied as 3000 Units, Tape and Reel Package Marking 1.5 STD LP3994LD-1.5 LP3994LDX-1.5 L028B 1.8 STD LP3994LD-1.8 LP3994LDX-1.8 L029B 3 www.national.com LP3994 Absolute Maximum Ratings ESD Rating (Note 4) (Notes 1, 2) Human Body Model 2KV Machine Model 200V If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Input Voltage Operating Conditions(Notes 1, 2) -0.3 to 6.5V Output Voltage -0.3 to (VIN + 0.3V) to 6.5V (max) Enable Input Voltage Input Voltage 2.5 to 5.5V Enable Input Voltage 0 to (VIN + 0.3V) -0.3 to (VIN + 0.3V) to 6.5V (max) Junction Temperature (TJ) Range -40˚C to 125˚C 150˚C Ambient Temperature (TA) Range (Note 5) -40 to 85oC Junction Temperature Lead Temp. microSMD 260˚C LLP 235oC Storage Temperature Thermal Properties -65 to 150˚C Junction to Ambient Thermal Resistance(Note 6) Continuous Power Dissipation(Note 3) θJA microSMD package Internally Limited 220oC/W θJA LLP package 88oC/W Electrical Characteristics(Notes 2, 7) Unless otherwise noted, VEN = 1.2, VIN = VOUT + 1.0V, CIN = 1 µF, IOUT = 1 mA, COUT = 1 µF. Typical values and limits appearing in normal type apply for TJ = 25˚C. Limits appearing in boldface type apply over the full temperature range for operation, −40 to +125˚C. (Notes 13, 14) Symbol Parameter Conditions Min Typ Max Units Device Output: VOUT ≤ 1.8V VIN ∆VOUT IQ Input Voltage 2.5 5.5 V -60 +60 mV 0.005 0.07 %/V IOUT = 1mA to 50mA 100 400 µV/mA microSMD: Output Voltage Tolerance Over full line and load regulation. Line Regulation Error VIN = (VOUT(NOM) + 1.0V) to 5.5V, IOUT = 1mA Load Regulation Error Quiescent Current LLP: IOUT = 0mA 15 35 IOUT = 50mA 22 50 IOUT = 0mA 15 40 IOUT = 50mA Quiescent Current(Disabled) VEN = 0.4V 25 65 0.001 1.5 µA Device Output: VOUT > 1.8V VIN ∆VOUT IQ Input Voltage 2.5 5.5 V -90 +90 mV 0.005 0.1 %/V 500 µV/mA Output Voltage Tolerance Over full line and load regulation. Line Regulation Error VIN = (VOUT(NOM) + 1.0V) to 5.5V, IOUT = 1mA Load Regulation Error IOUT = 1mA to 50mA 100 Dropout Voltage (where applicable) IOUT = 1mA 1.5 4.5 IOUT = 50mA 75 140 Quiescent Current microSMD: LLP: Quiescent Current(Disabled) IOUT = 0mA 18 50 IOUT = 50mA 22 60 IOUT = 0mA 20 55 IOUT = 50mA 22 65 0.001 1.5 VEN = 0.4V mV µA Full VOUT RANGE ILOAD Load Current (Notes 8, 9) ISC Short Circuit Current Limit (Note 12) www.national.com 0 µA 235 4 mA (Continued) Unless otherwise noted, VEN = 1.2, VIN = VOUT + 1.0V, CIN = 1 µF, IOUT = 1 mA, COUT = 1 µF. Typical values and limits appearing in normal type apply for TJ = 25˚C. Limits appearing in boldface type apply over the full temperature range for operation, −40 to +125˚C. (Notes 13, 14) Symbol PSRR En Parameter Power Supply Rejection Ratio Output noise Voltage (Note 9) Conditions Min Typ f = 100Hz, IOUT = 1mA to 50mA 70 f = 50kHz, IOUT = 1mA to 50mA 30 f = 1MHz, IOUT = 1mA 50 f = 1MHz, IOUT = 50mA 40 BW = 100Hz to 100kHz, VIN = 4.2V, IOUT = 1mA 95 TSHUTDOWN Thermal Shutdown Temperature Max dB µVRMS 160 Thermal Shutdown Hysteresis Units ˚C 20 Enable Control Characteristics IEN Maximum Input Current at VEN Input VEN = 0.0V and VIN = 5.5V VIL Low Input Threshold VIN = 2.5V to 5.5V VIH High Input Threshold VIN = 2.5V to 5.5V 0.015 µA 0.4 1.2 V V Timing Characteristics TON1 Turn On Time (Note 9) TON2 Transient Response 10 to 90% of VOUT(NOM) (Note 10) 10 20 To 95% Level (Note 11) 35 100 Line Transient Response |δVOUT| Figure 1 (Note 9) Load Transient Response |δVOUT| µS 20 Figure 2 (Note 9) 70 mV Note 1: Absolute Maximum Ratings are limits beyond which damage can occur. Operating Ratings are conditions under which operation of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics tables. Note 2: All Voltages are with respect to the potential at the GND pin. Note 3: Internal thermal shutdown circuitry protects the device from permanent damage Note 4: The human body is 100pF discharge through 1.5kW resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each pin. Note 5: In applications where high power dissipation and/or poor thermal resistance is present, the maximum ambient temperature may have to be derated. Maximum ambient temperature (TA(max)) is dependant on the maximum operating junction temperature (TJ(max-op)), the maximum power dissipation (PD(max)), and the junction to ambient thermal resistance in the application (θJA). This relationship is given by :- TA(max) = TJ(max-op) − (PD(max) x θJA) See Applications section. Note 6: Junction to ambient thermal resistance is highly application and board layout dependent. In applications where high maximum power dissipation exists, the thermal dissipation issues should be addressed in the board layout design. Note 7: Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm. Note 8: The device maintains the regulated output voltage without the load. Note 9: This electrical specification is guaranteed by design. Note 10: Time for VOUT to rise from 10 to 90% of VOUT(nom). Note 11: Time from VEN = 1.2V to VOUT = 95%(VOUT(nom)). Note 12: Short circuit current is measured on the input supply line at the point when the short circuit condition reduces the output voltage to 95% of its nominal value. Note 13: CIN, and COUT: Low ESR surface mont devices used in setting electrical characteristics. Note 14: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production at TJ = 25˚C or correlated using Statistical Quality Control methods. Operation over the temperature specification is guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control. Output Capacitor, Recommended Specifications Symbol Co Parameter Output Capacitor Conditions Capacitance(Note 15) ESR Min Typ 0.7 1.0 5 Max Units 500 mΩ µF Note 15: The capacitor tolerance should be ± 30% or better over the full temperature range. The full range of operating conditions for the capacitor in the application should be considered during device selection to ensure this minimum capacitance specification is met. X7R capacitor types are recommended to meet the full device temperature range, however X5R, Y5V, and Z5U types may be used with careful consideration of the application and its operating conditions. (See Capacitor Sections in Application Hints.) 5 www.national.com LP3994 Electrical Characteristics(Notes 2, 7) LP3994 Transient Test Conditions 20046504 FIGURE 1. Line Transient Response Requirement. 20046505 FIGURE 2. Load Transient Response Requirement. www.national.com 6 Unless otherwise specified, CIN = COUT = 1.0 µF Ceramic, Output Voltage Change vs Temperature Ground Current vs Load Current 20046510 20046511 Ground Current vs VIN, ILOAD = 1mA Short Circuit Current 20046513 20046512 Line Transient Response Load Transient Response 20046514 20046515 7 www.national.com LP3994 Typical Performance Characteristics. VIN = VOUT + 1.0V, TA = 25˚C, VEN pin is tied to VIN. LP3994 Typical Performance Characteristics. Unless otherwise specified, CIN = COUT = 1.0 µF Ceramic, VIN = VOUT + 1.0V, TA = 25˚C, VEN pin is tied to VIN. (Continued) Enable Start Up Timing, (VOUT = 1.8V) Enable Start Up Timing, (VOUT = 1.5V) 20046516 20046517 Ripple Rejection Noise Density (VIN = 4.2V) 20046519 20046518 www.national.com 8 NO-LOAD STABILITY EXTERNAL CAPACITORS The LP3994 will remain stable and in regulation with no external load. This is an important consideration in some circuits, for example CMOS RAM keep-alive applications. In common with most regulators, the LP3994 requires external capacitors for regulator stability. The LP3994 is specifically designed for portable applications requiring minimum board space and smallest components. These capacitors must be correctly selected for good performance and to ensure that their value remains within specification over the full operating range. CAPACITOR CHARACTERISTICS The LP3994 is designed to work with ceramic capacitors on the input and output to take advantage of the benefits they offer. For capacitance values around the 1µF value, ceramic capacitors give the circuit designer the best design options in terms of low cost and minimal area. Ceramic capacitors have the lowest ESR values, thus making them best for eliminating high frequency noise. The ESR of a typical 1µF ceramic capacitor is in the range of 20mΩ to 40mΩ, which easily meets the ESR requirement for stability for the LP3994. INPUT CAPACITOR An input capacitor is required for optimum operation and to ensure stability within the range of specified transient conditions. It is recommended that a 1.0µF capacitor be connected between the LP3994 input pin and ground (this capacitance value may be increased without limit). This capacitor must be located a distance of not more than 1cm from the input pin and returned to a clean analogue ground. Any good quality ceramic, tantalum, or film capacitor may be used at the input. For both input and output capacitors careful interpretation of the capacitor specification is required to ensure correct device operation. The capacitor value can change greatly dependant on the conditions of operation and capacitor type. In particular the output capacitor selection should take account of all the capacitor parameters to ensure that the specification is met within the application. Capacitance value can vary with DC bias conditions as well as temperature and frequency of operation. Capacitor values will also show some decrease over time due to aging. The capacitor parameters are also dependant on the particular case size with smaller sizes giving poorer performance figures in general. A study of manufacturers data on 0402 case size capacitors shows that these devices may drop below the minimum specified capacitance due to DC-Bias conditions in conjunction with other parameters such as temperature and are thus not recommended for use. Important: Tantalum capacitors can suffer catastrophic failures due to surge current when connected to a lowimpedance source of power (like a battery or a very large capacitor). If a tantalum capacitor is used at the input, it must be guaranteed by the manufacturer to have a surge current rating sufficient for the application. There are no requirements for the ESR (Equivalent Series Resistance) on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will remain ) 1.0µF over the entire operating temperature range. The temperature performance of ceramic capacitors varies by type. Capacitor type X7R is specified with a tolerance of ± 15% over the temperature range -55oC to +125oC. The X5R has a similar tolerance over the reduced temperature range of -55oC to +85oC. Most large value ceramic capacitors ( ≥ 2.2µF) are manufactured with Z5U or Y5V temperature characteristics, which results in the capacitance dropping by more than 50% as the temperature goes from 25˚C to 85˚C. Therefore X7R is recommended over these other capacitor types in applications where the temperature will change significantly above or below 25oC. Tantalum capacitors are less desirable than ceramic for use as output capacitors because they are more expensive when comparing equivalent capacitance and voltage ratings in the 1µF to 4.7µF range. Another important consideration is that tantalum capacitors have higher ESR values than equivalent size ceramics. This means that while it may be possible to find a tantalum capacitor with an ESR value within the stable range, it would have to be larger in capacitance (which means bigger and more costly) than a ceramic capacitor with the same ESR value. It should also be noted that the ESR of a typical tantalum will increase about 2:1 as the temperature goes from 25˚C down to -40˚C, so some guard band must be allowed. OUTPUT CAPACITOR Correct selection of the output capacitor is essential to ensure stable operation in the intended application. The output capacitor must meet all the requirements specified in the recommended capacitor table over all conditions in the application. These conditions include DC-Bias, frequency and temperature. Unstable operation may result if the capacitance drops below the minimum specified value. (See the Capacitor Characteristics section). The LP3994 is designed specifically to work with very small ceramic output capacitors. A 1.0µF ceramic capacitor (type X7R) with ESR between 5mΩ to 500mΩ, is suitable in the LP3994 application circuit. X5R type capacitors may be used but have a narrower temperature range. With these capacitors and others types (Y5V, Z6U) that may be used, selection of the capacitor for any application is dependant on the range of operating conditions and temperature range for that application. (see section on Capacitor Characteristics). It may also be possible to use tantalum or film capacitors at the device output, COUT (or VOUT), but these are not as attractive for reasons of size and cost (see the section Capacitor Characteristics). It is also recommended that the output capacitor be placed within 1cm from the output pin and returned to a clean ground line. 9 www.national.com LP3994 Application Hints LP3994 Application Hints ENABLE If the application does not require the Enable switching feature, the VEN pin should be tied to VIN to keep the regulator output permanently on. The LP3994 features an active high Enable pin, VEN, which turns the device on when pulled high. When not enabled the regulator output is off and the device typically consumes 1nA. To ensure proper operation, the signal source used to drive the VEN input must be able to swing above and below the specified turn-on/off voltage thresholds listed in the Electrical Characteristics section under VIL and VIH. www.national.com (Continued) 10 LP3994 Physical Dimensions inches (millimeters) unless otherwise noted micro SMD, 4 Bump, Package (TLA04) NS Package Number TLA04AAA The dimensions for X1, X2 and X3 are given as: X1 = 1.014 +/− 0.03mm X2 = 1.014 +/− 0.03mm X3 = 0.600 +/− 0.075mm 11 www.national.com LP3994 50mA CMOS Voltage Regulator with Enable Control Physical Dimensions inches (millimeters) unless otherwise noted (Continued) LLP, 6 Lead, Package (SOT23 Land) NS Package Number LDE06A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. 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