LP2950/LP2951 100 mA Low Dropout Voltage Regulators FEATURES APPLICATIONS * 5.0V, 3.3V and 3.0V Versions @ 100mA Output * Very Low Quiescent Current * Low Dropout Voltage * Extremely Tight Load and Line Regulation * Very Low Temperature Coefficient * Current & Thermal Limiting * Need Only 1 F for Stability * Offered in TO-263 & SOIC * Direct Replacement For LP2950/LP2951 Sockets * Battery Powered Systems * Cordless Telephones * Radio Control Systems * Portable/Palm Top/Notebook Computers * Portable Consumer Equipment * Portable Instrumentation * Avionics * SMPS Post-Regulator * Voltage Reference * Automotive Electronics LP2951 versions only * Error Flag Warns of Output Dropout * Logic-Controlled Electronic Shutdown * Output Programmable From 1.24 to 29V PRODUCT DESCRIPTION The LP2950 and LP2951 are low power voltage regulators. These devices are an excellent choice for use in battery-powered applications such as cordless telephones, radio control systems, and portable computers. The LP2950 and LP2951 features low quiescent current and very low dropout voltage (Typ. 50mV at light load and 380 mV at 100mA). This includes a tight initial tolerance of 0.5% typ., extremely good load and line regulation 0.05% typ., and very low output temperature coefficient, making the LP2950/LP2951 useful as a low-power voltage reference. The error flag output feature is used as power-on reset for warning of a low output voltage, due to falling voltage input of batteries. Another feature is the logic-compatible shutdown input which enables the regulator to be switched ON and OFF. The LP2950 is offered in a 3-pin TO-263 package compatible with other 5V, 3.0V & 3.3V regulators. The LP2951 is also available in 8-pin plastic, SO-8 packages. The regulator output voltage may be pin-strapped for 5.0V, 3.0V or 3.3V or programmed from 1.24V to 29V with an external pair of resistors. Look for SPX2950/51 for 150mA, for SPX2975 for 180mA and SPX2954 for 250mA. 8-Pin Surface Mount (S) OUTPUT 1 8 SENSE 2 ALPHA 7 SHUTDOWN GROUND INPUT 5V or 3.3V TAP 4 ERROR Top View LP2950 FEEDBACK AS2930 6 3 LP2951 5 TO-263-3 (T) 1 2 3 VIN GND VOUT Top View Rev. 11/2/00 LP2950/51 ABSOLUTE MAXIMUM RATINGS Power Dissipation ..................................Internally Limited Lead Temp. (Soldering, 5 Seconds) ......................... 260C Storage Temperature Range .......................-65 to +150C Operating Junction Temperature Range LP2951 ........................................... -55C to +150C LP2950AC/LP2950C...................... -40C to +125C LP2951AC/LP2951C...................... -40C to +125C Input Supply Voltage ................................................ -0.3V to +30V Feedback Input Voltage ............................................ -1.5V to +30V Shutdown Input Voltage............................................ -0.3V to +30V Error Comparator Output .......................................... -0.3V to +30V ESD Rating ...................................................................... 2kV Min ELECTRICAL CHARACTERISTICS at Vs=15V, Ta=25C, unless otherwise noted. PARAMETER 3 V Versions Output Voltage Output Voltage 3.3 V Versions Output Voltage Output Voltage 5 V Versions Output Voltage Output Voltage CONDITIONS (Note 2) LP2951 Min. Typ. Max. LP2950AC LP2951AC Min. Typ. Max. LP2950C LP2951C Typ. Max. Min. 2.985 2.970 2.964 2.958 3.0 3.0 3.0 3.0 3.015 3.030 3.036 3.042 2.970 2.955 2.940 2.928 3.0 3.0 3.0 3.0 3.030 3.045 3.060 3.072 V 3.3 3.3 3.3 3.317 3.333 3.340 3.267 3.251 3.234 3.3 3.3 3.3 3.333 3.350 3.366 V UNITS TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX 2.985 3.0 3.015 2.964 2.955 3.0 3.036 3.045 TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX 3.284 3.3 3.317 3.340 3.284 3.267 3.260 3.251 3.3 3.350 3.254 3.3 3.346 3.221 3.3 3.379 V TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX 4.975 5.0 5.025 5.0 5.06 5.075 5.0 5.0 5.0 5.0 5.025 5.050 5.06 5.07 4.95 4.925 4.90 4.88 5.0 5.0 5.0 5.0 5.05 5.075 5.10 5.12 V 4.94 4.925 4.975 4.95 4.94 4.93 3.260 V V All Voltage Options Output Voltage Temperature Coefficient Line Regulation (Note 3) Load Regulation (Note 3) Dropout Voltage (Note 5) Ground Current Current Limit 20 120 20 120 50 120 ppm/C (Note 1) 6V Vin 30V (Note 4) 0.03 0.1 0.03 0.1 0.04 0.2 % 100 A IL 100 mA 0.04 0.1 0.04 0.1 0.1 0.2 % IL = 100 A IL = 100 mA IL = 100 A IL = 100 mA 50 380 150 8 80 450 170 12 50 380 150 8 80 450 170 12 50 380 150 8 80 450 170 12 mV mV 130 200 130 200 130 200 mA 0.05 0.2 0.05 0.2 0.05 0.2 %/W VOUT = 0 Thermal Regulation Output Noise, 10Hz to 100KHz 8-Pin Versions only Reference Voltage Reference Voltage Feedback Pin Bias Current 430 160 100 CL = 1F CL = 200 F CL = 13.3 F (Bypass = 0.01 F pins 7 to 1(LP2951)) 1.22 Over Temperature (Note 6) LP2951 1.235 1.19 40 430 160 100 430 160 100 1.25 1.22 LP2951AC 1.235 1.25 1.27 1.19 1.27 60 40 60 1.21 V rms V rms V rms LP2951C 1.235 1.26 1.185 1.285 40 A mA 60 V V nA Rev. 11/2/00 LP2950/51 PARAMETER CONDITIONS (Note 2) LP2951 Min. Typ. Max. LP2950AC LP2951AC Min. Typ. Max. Min. LP2950C LP2951C Typ. Max. UNITS 8-Pin Versions only (Continued) Reference Voltage Temperature Coefficient Feedback Pin Bias Current Temperature Coefficient Error Comparator 20 20 50 ppm/C 0.1 0.1 0.1 nA/C ( Note 7 ) Output Leakage Current VOH = 30V 0.01 1 0.01 1 0.01 1 A Output Low Voltage VIN = 4.5V IOL = 400A (Note 8) 150 250 150 250 150 250 mV Upper Threshold Voltage Lower Threshold Voltage Hysteresis 40 60 (Note 8) 75 (Note 8) 15 40 60 95 75 40 95 60 mV 75 15 95 15 mV mV Shutdown Input Input logic Voltage Low (Regulator ON) High (Regulator OFF) VS = 2.4V VS= 30V (Note 9) 1.3 0.6 2 1.3 0.7 1.3 2 0.7 2 V V A A A Shut down Pin Input 30 50 30 50 30 50 Current 675 800 675 800 675 800 Regulator Output 3 10 3 10 3 10 Current in Shutdown Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range. Note 2: Unless otherwise specified all limits guaranteed for TJ = 25C, VIN = 6V, IL = 100A and CL = 1F. Additional conditions for the 8-pin versions are feedback tied to 5V tap and output tied to output sense (VOUT = 5V) and VSHUTDOWN 0.8V. Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specification for thermal regulation. Note 4: Line regulation for the LP2951 is tested at 150C for IL = 1mA. For IL = 100 A and TJ = 125C, line regulation is guaranteed by design to 0.2%. See typical performance characteristics for line regulation versus temperature and load current. Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below its nominal value measured at 1V differential at very low values of programmed output voltage, the minimum input supply voltage of 2V ( 2.3V over temperature) must be taken into account. Note 6: VREF VOUT (VIN - 1V), 2.3 VIN30V, 100AIL 100 mA, TJ TJMAX. Note 7: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at 6V input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = VOUT/VREF = (R1 + R2)/R2. For example, at a programmed output voltage of 5V, the error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant as a percent of VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed. Note 8: VSHUTDOWN 2V, VIN 30V, VOUT =0, Feedback pin tied to 5V Tap. Note 9: All typical values are not guaranteed. The value could vary from lot to lot. BLOCK DIAGRAMU N R E G U L A T E D D C 7 + IN P U T FE E DB AC K 5V @ 100m A MAX 1 8 OUTPUT 2 SEN SE + _ FRO M CM O S OR TTL 3 1 8 0 k .. 6 ER R OR A M P L IF IE R 3 3 0 k .. 5V T A P SH UTD O W N 6 0 k .. + 60 m V + _ + 1 .2 3 V E R R O R D E T E C T IO N CO M PAR ATO R 5 + 1 F.. ______ ER RO R TO C M O S O R TTL 4 RE FER EN CE GRO UND L P 2 9 5 0 a n d L P 2 9 5 1 B lo c k D ia g ra m Rev. 11/2/00 LP2950/51 APPLICATION HINTS EXTERNAL CAPACITORS The stability of the LP2950/LP2951 requires a 1.0 F or greater capacitor between output and ground. Oscillation could occur without this capacitor. Most types of tantalum or aluminum electrolytic works fine here. For operations below -25C solid tantalum is recommended since the many aluminum types have electrolytes that freeze at about -30C. The ESR of about 5 or less and resonant frequency above 500 kHz are the most important parameters in the value of the capacitor. The capacitors value may be increased without limit. At lower values of output current, less output capacitance is required for stability. For the currents below 10 mA the value of the capacitor can be reduced to 0.33 F and 0.1 F for 1 mA. More output capacitance is needed for the 8-pin version at voltages below 5V since it runs the error amplifier at lower gain. At worst case 3.3 F or greater must be used for the condition of 100 mA load at 1.23V output. The LP2950/51 unlike other low dropout regulators will remain stable and in regulation with no load in addition to the internal voltage divider. This feature is especially important in applications like CMOS RAM keep-alive. When setting the output voltage of the LP2950/51 version with external resistors, a minimum load of 1A is recommended If there is more than 10 inches of wire between the input and the AC filter capacitor or if a battery is used as the input then a 1A tantalum or aluminum electrolytic capacitor should be placed from the input to the ground. Instability can occur if there is stray capacitance to the LP2951 feedback terminal (pin 7). This could cause more problems when using a higher value of external resistors to set the output voltage. This problem can be fixed by adding a 100 pF capacitor between 4.75V OUTPUT VOLTAGE PROGRAMMING THE OUTPUT VOLTAGE OF LP2951 The LP2951 may be pin-strapped for 5V using its internal voltage divider by tying Pin 1 (output) to Pin 2 (sense) and Pin 7 (feedback) to Pin 6 (5V Tap). Also, it may be programmed for any output voltage between its 1.235V reference and its 30V maximum rating . As seen in Figure 2, an external pair of resistors is required. Refer to the below equation for the programming of the output voltage: VOUT = VREF x (1 + R1/R2)+ IFBR1 The VREF is 1.235 and IFB is the feedback bias current, nominally -20 nA. The minimum recommended load current of 1 A forces an upper limit of 1.2 M on value of R2. If no load is presented the IFB produces an error of typically 2% in VOUT which may be eliminated at room temperature by trimming R1. To improve the accuracy choose the value of R2 = 100k this reduces the error by 0.17% and increases the resistor program current by 12 A. Since the LP2951 typically draws 60 A at no load with Pin 2 open-circuited this is a small price to pay REDUCING OUTPUT NOISE It may be an advantage to reduce the AC noise present at the output. One way is to reduce the regulator bandwidth by increasing the size of the output capacitor. This is the only way that noise can be reduced on the 3 lead LP2950 but is relatively inefficient, as increasing the capacitor from 1 F to 220 F only decreases the noise from 430 V to 160 VRMS for a 100 kHz bandwidth at 5V output. Noise could also be reduced fourfold by a bypass capacitor across R1, since it reduces the high frequency gain from 4 to unity. Pick _______ ERROR* +5.0V INPUT VOLTAGE Figure 1 shows the timing diagram depicting the ERROR signal and the regulator output voltage as the LP2951 input is ramped up and down. The ERROR signal becomes low at around 1.3V input, and goes high around 5V input (input voltage at which VOUT = 4.75 ). Since the LP2951's dropout voltage is load dependent, the input voltage trip point (around 5V) will vary with the load current. The output voltage trip point (approx. 4.75V) does not vary with load. The error comparator has an open-collector output, which requires an external pull-up resistor. Depending on the system requirements the resistor may be returned to 5V output or other supply voltage. In determining the value of this resistor, note that the output is rated to sink 400A, this value adds to battery drain in a low battery condition. Suggested values range from 100K to 1M. If the output is unused this resistor is not required. +1.3V + CBYPASS 1 / 2R1 x 200 Hz + * See Application Info. _______ Figure 1. ERROR Output Timing output and feedback and increasing the output capacitor to at least 3.3 F. or choose 0.01 F. When doing this, the output capacitor must be increased to 3.3 F to maintain stability. These changes reduce the output noise from 430 V to 100 VRMS for a 100 kHz bandwidth at 5V output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages. ERROR DETECTION COMPARATOR OUTPUT The Comparator produces a logic low output whenever the LP2951 output falls out of regulation by more than around 5%. This is around 60 mV offset divided by the 1.235 reference voltage. This trip level remains 5% below normal regardless of the programmed output voltage of the regulator. Rev. 11/2/00 LP2950/ LP2951 TYPICAL PERFORMANCE CHARACTERISTIC INPUT CURRENT DROPOUT CHARACTERISTICS RL=50k 3 RL=50k 2 GROUND PIN CURRENT (mA) INPUT CURRENT (A) 4 200 RL = 50k 175 150 125 100 RL = 8 75 50 1 1 0.1 25 0.01 0.1 0 0 1 2 3 4 5 0 6 1 10 3 150 OUTPUT VOLTAGE VS. TEMP OF 3 REPRESENTATIVE UNITS GROUND CURRENT 5.0 4.98 0.2% 4.96 240 160 80 0 0 25 50 IL = 0 120 40 4.94 -75 -50 -25 IL= 1mA 200 75 100 125 150 0 1 2 3 4 5 6 7 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 8 QUIESCENT CURRENT (A) GROUND CURRENT GROUND CURRENT (mA) 8 12 IL=100mA 10 8 6 4 0 -75 -50 -25 0 25 50 0 75 100 125 150 1 TEMPERATURE (C) 3 4 5 6 7 50 IL = 100A 0 0 25 50 75 100 125 150 TEMPERATURE (C) 8 9 10 0 25 50 75 100 125 150 TEMPERATURE (C) SHORT CIRCUIT CURRENT 170 400 300 200 TJ = 25C 100 0 -75 -50 -25 7 200 -75 -50 -25 8 SHORT CIRCUIT CURRENT (mA) ~ ~ 100 DROP-OUT VOLTAGE (mV) DROP-OUT VOLTAGE (mV) 400 300 2 500 IL = 100mA 6 V IN=6V IL=100mA DROP-OUT VOLTAGE DROP-OUT VOLTAGE 500 5 220 INPUT VOLTAGE 600 4 180 2 4 3 QUIESCENT CURRENT 14 VIN = 6V IL = 100mA 2 240 16 12 1 INPUT VOLTAGE (VOLTS) GROUND CURRENT GROUND CURRENT RL=50 0 INPUT VOLTAGE (VOLTS) TEMPERATURE (C) 16 150 INPUT CURRENT 320 GROUND CURRENT (A) 5.02 10 LOAD CURRENT (mA) 280 5.04 1 INPUT VOLTAGE (VOLTS) INPUT VOLTAGE (VOLTS) 5.06 2 INPUT CURRENT (mA) OUTPUT VOLTAGE (VOLTS) 225 5 0 OUTPUT VOLTAGE (V) QUIESCENT CURRENT 10 250 6 100A 1mA 10mA OUTPUT CURRENT 100mA 160 150 140 130 120 110 110 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) Rev. 11/2/00 LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) LP2951 COMPARATOR SINK CURRENT ERROR COMPARATOR OUTPUT 4 HYSTERESIS 2 0 T A = 125C 2.0 1.5 T A = 25C 1.0 T A = -55C 0.5 PULLUP RESISTOR TO SEPARATE 5V SUPPLY 1 0 2 3 0.0 4 0 CL = 1F IL = 1mA VOUT = 5V -50 mV ~ ~ 8V 4V 0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 5 200 OUTPUT LOW VOLTAGE (V) 10 600 400 800 TIME(s) RIPPLE REJECTION OUTPUT IMPEDANCE RIPPLE REJECTION 90 90 80 80 IO = 1mA 2 IO = 100mA 1 0.5 VOUT = 5V CL = 1F 0.2 0.1 0.05 70 IL = 0 60 50 40 IL = 100A CL = 1F VIN = 6V V OUT = 5V 30 0.02 RIPPLE REJECTION (dB) IO = 100A 5 RIPPLE REJECTION (dB) 20 0.01 10 100 1K 10K 100K 1M 102 103 104 105 FREQUENCY (Hz) LP2951 MINIMUM OPERATING VOLTAGE LP2951 FEEDBACK BIAS CURRENT 25 50 10 0 -10 60 150 40 LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) 200 100 50 0 -50 CL = 1F VOUT = 5V -100 ~ ~ 100 mA 0 25 50 75 100 125 150 1 2 TIME (ms) 3 -150 T A = 25C -200 -2.0 20 0 -20 CL = 1F VOUT = 5V -40 4 5 T A = 55C -1.5 -1.0 -0.5 0 0.5 1.0 ENABLE TRANSIENT -60 ~ ~ 100 A 0 TA =1 25C FEEDBACK VOLTAGE (V) 100 A 106 -100 -250 A 100 105 -50 LOAD TRANSIENT RESPONSE LOAD TRANSIENT RESPONSE 80 104 103 PIN 7 DRIVEN BY EXTERNAL SOURCE (REGULATOR RUN OPEN LOOP) 0 TEMPEATURE (C) TEMPERATURE 250 102 50 -30 -75 -50 -25 75 100 125 150 IL = 10mA 101 FEEDBACK CURRENT (A) BIAS CURRENT (nA) 0 40 LP2951 FEEDBACK PIN CURRENT -20 0.01 -75 -50 -25 50 106 20 0.1 60 FREQUENCY (Hz) FREQUENCY (Hz) 1 CL= 1F V IN = 6V VOUT = 5V IL = 10mA 20 101 10 70 30 SHUTDOWN OUTPUT PINOUT VOLTAGE (V) VOLTAGE (V) OUTPUT IMPEDANCE (OHMS) 50 mV 6V INPUT VOLTAGE (V) MINIMUM OPERATING VOLTAGE (V) INPUT OUTPUT VOLTAGE VOLTAGE CHANGE SINK CURRENT (mA) COMPARATOR OUTPUT (V) 100 mV VOUT = 5V 6 -2 LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) LINE TRANSIENT RESPONSE 2.5 8 7 6 5 4 3 2 1 0 IL = 10mA VIN = 8V CL = 10F V OUT = 5V 2 0 -2 0 4 8 12 TIME (ms) 16 20 -100 0 100 200 300 400 500 600 700 TIME Rev. 11/2/00 LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) LP2950 MAXIUM RATED OUTPUT TO-92 PACKAGE 0.25" LEADS SOLDERED TO PC BOARD 80 TJMAX = 125 C 60 40 TA=25 C TA = 85 C 20 300 200 100 40 10 20 15 25 -75 -50 -25 30 25 0 50 0 75 100 125 150 THERMAL RESPONSE 1.6 4 3.0 POWER OUTPUT VOLTAGE DISSIPATION (W) CHANGE (mV) 1.8 1.4 1.2 1.0 0.8 2 0 -2 ~ ~ 1 1.25W 75 100 125 150 15 20 25 30 IL = 100mA CL = 1F 2.5 CL = 220F 2.0 1.5 CL = 3.3F 1.0 0.5 0 0.0 -1 0.6 10 OUTPUT NOISE 3.5 0 10 TEMPERATURE (C) 20 30 40 102 50 TIME (s) 10 3 104 105 FREQUENCY (Hz) LINE REGULATION RIPPLE REJECTION 80 30 IL = 50A 25 20 70 IL = 100A 15 RIPPLE REJECTION (dB) OUTPUT VOLTAGE CHANGE (mV) 5 INPUT VOLTAGE (V) 5 25 50 TA = 85C TEMPERATURE (C) SHUTDOWN THRESHOLD VOLTAGE -75 -50 -25 0 TA = 50C 0 INPUT VOLTAGE (V) SHUTDOWN THRESHOLD VOLTAGE (V) 60 0 5 TJMAX = 125 C VOUT = 5V TA = 25C 80 20 0 0 8-PIN MOLDED DIP SOLDERED TO PC BOARD 100 VOLTAGE NOISE SPECTRAL DENSITY (V/Hz) OUTPUT CURRENT (mA) 120 OUTPUT CURRENT (mA) ) PIN 2 TO PIN 4 RESISTANCE (k) 120 100 LP2950 MAXIUM RATED OUTPUT CURRENT LP2951 DIVIDER RESISTANCE 400 TJ = 150 C 10 5 IL = 1mA 0 ~ ~ 10 5 0 TJ = 125 C IL = 100A 60 IL = 100mA 50 40 30 CL = 1F VIN = 6V VOUT = 5V 20 -5 10 -10 5 10 15 20 INPUT VOLTAGE (V) 25 30 101 102 10 3 104 105 106 FREQUENCY (Hz) Rev. 11/2/00 LP2950/LP2951 TYPICAL APPLICATIONS +VIN 100K 8 ERROR +VIN ______ ERROR 5 OUTPUT VOUT 1.2 to 30V 1 LP2951 + SHUTDOWN 3 R1 SD INPUT GND 4 3.3uF .01uF FB 7 1.23V VREF R2 Figure 1. Adjustable Regulator +VIN +VIN 470K .. 8 5 ______ ERROR 470K +VIN .. VOUT 8 VOUT 1 ERROR 5 OUTPUT LP2951 ______ ERROR VOUT R1 SD GND 4 FB 1uF SHUTDOWN INPUT 7 3 Fig.2 Latch Off When Error Flag Occurs *VOUT = VIN SD GND 4 R2 1 LP2951 + 3 +VIN FB 7 *MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 4mV TO 400mV. DEPENDING ON LOAD CURRENT. CURRENT LIMIT IS TYPICALLY 160mA Fig.3 Wide Input Voltage Range Current Limiter Rev. 11/2/00 LP2950/LP2951 TYPICAL APPLICATIONS (continued) + 6V SEALED 120K .. LEADACID BATTERY SOURCE FB 1.5K .. 8 1N457 +VIN AS385 VOUT 1 MAIN V- LP2951 SENSE 400K .. FOR 5.5 V 3 100K .. MEMORY V+ 2 + 1uF SD GND 4 20K .. NI-CAD BACKUP BATTERY Fig.4 Low Battery Disconnect 8 39k .. 2 SENSE +VIN 5 ______ ERROR VOUT RESET - 3 C4 + +VOUT = 5V + 1uF LP2951 SD FB 39k .. 1% 1 GND 4 7 TAP 6 100k .. C1 100k .. + 6V LEADACID BATTERY 1% 1k .. <5.8V** C2 + 100k .. <6.0V** 1% 100k .. - 1k .. C3 + <6.2V** R3 1% 10k .. 20k .. * OPTIONAL LATCH OFF WHEN DROPOUT OCCURS. ADJUST R3 FOR C2 SWITCHING WHEN VIN IS 6.0V * OUTPUTS GO LOW WHEN V IN DROPS BELOW DESGNATED THRESHHOLDS Fig. 5 Regulator with State-of-Charge Indicator Rev. 11/2/00 LP2950/LP2951 TYPICAL APPLICATIONS (continued) +VIN 8 3 AUX SHUTDOW INPUT +VIN SD 10K .. _______ 5 ERROR 5 DEGREE SHUTDOWN FLAG LP2951 OFF ON VOUT FB GND 4 + TEMP SENSOR 1 7 AS35 - EXTERNAL CIRCUIT PROTECTED FROM OVER TEMPERATURE (V+ GOES OFF WHEN TEMP > 125) OR RELAY 8.2K .. Fig 6. System Over Temperature Protection +5V 4 4.7mA 20mA UNREGULATED INPUT 8 OUTPUT +V IN VOUT 1N4001 LP2951 FB 0.1uF 5 1 IN VOUT 7 2 4 Fig. 7 360K .. 1N457 VTAP FB 7 330K .. 27K LP2951 3 GND 1 SENSE GND 4 .. 5V 2 OUTPUT + 4.7uF MIN VOLTAGE = 4V Open Circuit Detector for 4mA to 20mA Current Loop 2N5432 LOAD 50mA TO 300 mA Fig 8. 300 mA Regulator with 0.75V Rev. 11/2/00 LP2950/LP2951 SCHEMATIC DIAGRAM Rev. 11/2/00 LP2950/LP2951 ORDERING INFORMATION Ordering No. LP2950AS LP2950AS-3.0 LP2950AS-3.3 LP2950AS-5.0 LP2950CS LP2950CS-3.0 LP2950CS-3.3 LP2950CS-5.0 LP2950AT LP2950AT-3.0 LP2950AT-3.3 LP2950AT-5.0 LP2950CT LP2950CT-3.0 LP2950CT-3.3 LP2950CT-5.0 Precision Output Voltage Packages 1% 1% 1% 1% 0.5% 0.5% 0.5% 0.5% 1% 1% 1% 1% 0.5% 0.5% 0.5% 0.5% Adj 3.0V 3.3V 5.0V Adj 3.0V 3.3V 5.0V Adj 3.0V 3.3V 5.0V Adj 3.0V 3.3V 5.0V 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Main Offices: 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: sales@sipex.com 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 935-7600 FAX: (408) 934-7500 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others. Rev. 11/2/00