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| LP2950/LP2951 100 mA Low Dropout Voltage Regulators FEATURES * 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 * Error Flag Warns of Output Dropout * Logic-Controlled Electronic Shutdown * Output Programmable From 1.24 to 29V APPLICATIONS * 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 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 SENSE SHUTDOWN GROUND 1 2 8 TO-263-3 (T) INPUT FEEDBACK 5V or 3.3V TAP ERROR 1 AS2930 3 LP2951 6 4 5 ALPHA 7 LP2950 2 3 Top View 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 CONDITIONS (Note 2) TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX TJ = 25C -25C TJ 85C Full Operating Temperature 100 A IL 100 mA TJ TJMAX LP2951 Min. Typ. Max. 2.985 2.964 2.955 3.0 3.015 3.036 3.045 LP2950AC LP2951AC Min. Typ. Max. 2.985 2.970 2.964 2.958 3.0 3.0 3.0 3.0 3.015 3.030 3.036 3.042 Min. 2.970 2.955 2.940 2.928 LP2950C LP2951C Typ. Max. 3.0 3.0 3.0 3.0 3.030 3.045 3.060 3.072 UNITS V Output Voltage 3.3 V Versions Output Voltage 3.0 V 3.284 3.260 3.251 3.3 3.317 3.340 3.284 3.267 3.260 3.254 3.3 3.3 3.3 3.3 3.317 3.333 3.340 3.346 3.267 3.251 3.234 3.221 3.3 3.3 3.3 3.3 3.333 3.350 3.366 3.379 V Output Voltage 5 V Versions Output Voltage 3.3 3.350 V 4.975 4.94 4.925 5.0 5.025 5.06 5.075 Output Voltage All Voltage Options Output Voltage Temperature Coefficient Line Regulation (Note 3) Load Regulation (Note 3) Dropout Voltage (Note 5) Ground Current Current Limit Thermal Regulation Output Noise, 10Hz to 100KHz 5.0 4.975 4.95 4.94 4.93 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 V 20 (Note 1) 6V Vin 30V (Note 4) 100 A IL 100 mA IL = 100 A IL = 100 mA IL = 100 A IL = 100 mA VOUT = 0 CL = 1F CL = 200 F CL = 13.3 F (Bypass = 0.01 F pins 7 to 1(LP2951)) 1.22 Over Temperature (Note 6) 1.19 0.03 0.04 50 380 150 8 130 0.05 430 160 100 120 0.1 0.1 80 450 170 12 200 0.2 20 0.03 0.04 50 380 150 8 130 0.05 430 160 100 120 0.1 0.1 80 450 170 12 200 0.2 50 0.04 0.1 50 380 150 8 130 0.05 430 160 100 120 0.2 0.2 80 450 170 12 200 0.2 ppm/C % % mV mV A mA mA %/W V rms V rms V rms 8-Pin Versions only Reference Voltage Reference Voltage LP2951 1.235 1.25 1.27 1.22 1.19 LP2951AC 1.235 1.25 1.27 1.21 1.185 LP2951C 1.235 1.26 1.285 V V Feedback Pin Bias Current 40 60 40 60 40 60 nA Rev. 11/2/00 LP2950/51 PARAMETER 8-Pin Versions only (Continued) Reference Voltage Temperature Coefficient Feedback Pin Bias Current Temperature Coefficient Error Comparator Output Leakage Current Output Low Voltage Upper Threshold Voltage Lower Threshold Voltage Hysteresis Shutdown Input Input logic Voltage Low (Regulator ON) High (Regulator OFF) VS = 2.4V VS= 30V (Note 9) 1.3 2 0.6 2 1.3 0.7 2 1.3 0.7 V V A A A 20 ( Note 7 ) 0.1 0.1 0.1 nA/C 20 50 ppm/C CONDITIONS (Note 2) LP2951 Min. Typ. Max. LP2950AC LP2951AC Min. Typ. Max. Min. LP2950C LP2951C Typ. Max. UNITS VOH = 30V VIN = 4.5V IOL = 400A (Note 8) (Note 8) (Note 8) 0.01 150 40 60 75 15 1 250 40 95 0.01 150 60 75 15 1 250 40 95 0.01 150 60 75 15 1 250 A mV mV 95 mV mV 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 FE E DB AC K 8 IN P U T 1 OUTPUT 5V @ 100m A MAX 2 SEN SE + _ FRO M CM O S OR TTL 1 8 0 k .. 6 ER R OR A M P L IF IE R 5V T A P 3 SH UTD O W N 3 3 0 k .. + 1F .. 6 0 k .. + 60 m V 5 ______ ER RO R + _ E R R O R D E T E C T IO N CO M PAR ATO R + 1 .2 3 V RE FER EN CE TO C M O S O R TTL 4 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 _______ ERROR* 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. 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 +5.0V INPUT VOLTAGE +1.3V + + CBYPASS 1 / 2R1 x 200 Hz 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. * See Application Info. _______ Figure 1. ERROR Output Timing output and feedback and increasing the output capacitor to at least 3.3 F. 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 DROPOUT CHARACTERISTICS INPUT CURRENT QUIESCENT CURRENT 6 OUTPUT VOLTAGE (VOLTS) 250 200 175 150 125 100 75 50 25 0 0 1 2 3 4 5 6 0 1 2 3 10 150 INPUT VOLTAGE (VOLTS) RL = 8 GROUND PIN CURRENT (mA) 10 225 INPUT CURRENT (A) 5 4 RL=50k RL = 50k 1 3 RL=50k 2 1 0 INPUT VOLTAGE (VOLTS) OUTPUT VOLTAGE VS. TEMP OF 3 REPRESENTATIVE UNITS 0.1 0.01 0.1 1 10 150 LOAD CURRENT (mA) GROUND CURRENT INPUT CURRENT 5.06 5.04 5.02 5.0 4.98 4.96 4.94 320 280 GROUND CURRENT (A) 240 200 160 120 80 40 0 0 1 2 3 4 5 6 7 8 IL= 1mA IL = 0 0.2% 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 OUTPUT VOLTAGE (V) INPUT CURRENT (mA) RL=50 -75 -50 -25 0 25 50 75 100 125 150 INPUT VOLTAGE (VOLTS) GROUND CURRENT 7 8 9 10 TEMPERATURE (C) GROUND CURRENT INPUT VOLTAGE (VOLTS) QUIESCENT CURRENT 16 GROUND CURRENT (mA) 16 QUIESCENT CURRENT (A) 240 14 GROUND CURRENT 12 10 8 6 4 2 IL=100mA 220 V IN=6V IL=100mA 12 VIN = 6V IL = 100mA 200 8 180 4 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) 0 0 1 2 3 4 5 6 7 8 INPUT VOLTAGE -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) DROP-OUT VOLTAGE DROP-OUT VOLTAGE SHORT CIRCUIT CURRENT DROP-OUT VOLTAGE (mV) 500 400 300 100 50 0 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) IL = 100A DROP-OUT VOLTAGE (mV) IL = 100mA SHORT CIRCUIT CURRENT (mA) 600 500 400 300 170 160 150 140 130 120 110 110 -75 -50 -25 ~ ~ 200 TJ = 25C 100 0 100A 1mA 10mA 100mA OUTPUT CURRENT 0 25 50 75 100 125 150 TEMPERATURE (C) Rev. 11/2/00 LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) ERROR COMPARATOR OUTPUT LP2951 COMPARATOR SINK CURRENT LINE TRANSIENT RESPONSE 8 COMPARATOR OUTPUT (V) VOUT = 5V SINK CURRENT (mA) 2.5 2.0 INPUT OUTPUT VOLTAGE VOLTAGE CHANGE T A = 125C 100 mV 50 mV 0 -50 mV ~ ~ CL = 1F IL = 1mA VOUT = 5V 6 4 HYSTERESIS 1.5 1.0 T A = 25C 2 0 -2 0 1 PULLUP RESISTOR TO SEPARATE 5V SUPPLY T A = -55C 8V 6V 4V 0 200 400 TIME(s) 0.5 0.0 4 5 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 OUTPUT LOW VOLTAGE (V) 2 3 600 800 INPUT VOLTAGE (V) OUTPUT IMPEDANCE RIPPLE REJECTION RIPPLE REJECTION OUTPUT IMPEDANCE (OHMS) 10 RIPPLE REJECTION (dB) 90 IO = 100A 90 80 RIPPLE REJECTION (dB) CL= 1F V IN = 6V VOUT = 5V 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 10 80 70 IL = 0 IO = 1mA IO = 100mA 70 60 50 40 30 20 IL = 10mA 60 50 40 30 20 CL = 1F VIN = 6V V OUT = 5V IL = 100A VOUT = 5V CL = 1F IL = 10mA 100 1K 10K 100K 1M 101 102 103 104 105 106 101 102 103 104 105 106 FREQUENCY (Hz) LP2951 MINIMUM OPERATING VOLTAGE MINIMUM OPERATING VOLTAGE (V) FREQUENCY (Hz) LP2951 FEEDBACK BIAS CURRENT FREQUENCY (Hz) LP2951 FEEDBACK PIN CURRENT 10 20 FEEDBACK CURRENT (A) 50 0 -50 TA =1 25C PIN 7 DRIVEN BY EXTERNAL SOURCE (REGULATOR RUN OPEN LOOP) 1 BIAS CURRENT (nA) 10 0 -100 -150 T A = 25C -10 0.1 -20 0.01 -75 -50 -25 -30 -75 -50 -25 -200 -250 T A = 55C 0 25 50 75 100 125 150 0 25 50 75 100 125 150 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 TEMPERATURE LOAD TRANSIENT RESPONSE TEMPEATURE (C) LOAD TRANSIENT RESPONSE FEEDBACK VOLTAGE (V) ENABLE TRANSIENT SHUTDOWN OUTPUT PINOUT VOLTAGE (V) VOLTAGE (V) 250 200 LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) 80 60 40 20 0 -20 -40 -60 ~ ~ CL = 1F VOUT = 5V 7 6 5 4 3 2 1 0 2 0 -2 -100 0 100 200 300 400 500 600 700 TIME IL = 10mA VIN = 8V CL = 10F V OUT = 5V 150 100 50 0 -50 -100 ~ ~ CL = 1F VOUT = 5V 100 mA A 100 100 A A 100 0 1 2 TIME (ms) 3 4 5 0 4 8 12 16 20 TIME (ms) Rev. 11/2/00 LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) LP2950 MAXIUM RATED OUTPUT LP2951 DIVIDER RESISTANCE 120 TO-92 PACKAGE PIN 2 TO PIN 4 RESISTANCE (k) ) 400 120 100 80 60 40 20 LP2950 MAXIUM RATED OUTPUT CURRENT 8-PIN MOLDED DIP SOLDERED TO PC BOARD TJMAX = 125 C VOUT = 5V TA = 25C 100 OUTPUT CURRENT (mA) 0.25" LEADS SOLDERED TO PC BOARD 300 80 60 40 20 0 0 5 10 15 20 25 30 TA = 85 C TJMAX = 125 C 200 OUTPUT CURRENT (mA) TA=25 C TA = 50C TA = 85C 100 0 -75 -50 -25 0 25 50 75 100 125 150 0 0 5 10 15 20 25 30 INPUT VOLTAGE (V) SHUTDOWN THRESHOLD VOLTAGE TEMPERATURE (C) THERMAL RESPONSE INPUT VOLTAGE (V) OUTPUT NOISE SHUTDOWN THRESHOLD VOLTAGE (V) 1.8 POWER OUTPUT VOLTAGE DISSIPATION (W) CHANGE (mV) 5 VOLTAGE NOISE SPECTRAL DENSITY (V/Hz) 3.5 3.0 2.5 CL = 220F IL = 100mA CL = 1F 1.6 1.4 1.2 1.0 0.8 0.6 -75 -50 -25 0 25 50 75 100 125 150 4 2 0 -2 ~ ~ 1 0 -1 0 10 20 30 40 50 1.25W 2.0 1.5 1.0 0.5 0.0 102 10 3 104 105 CL = 3.3F TEMPERATURE (C) TIME (s) FREQUENCY (Hz) LINE REGULATION RIPPLE REJECTION 30 OUTPUT VOLTAGE CHANGE (mV) 80 IL = 50A RIPPLE REJECTION (dB) IL = 100A TJ = 150 C IL = 1mA 25 20 15 10 5 0 ~ ~ 10 5 0 -5 -10 5 10 15 20 TJ = 125 C 70 60 50 40 30 20 10 CL = 1F VIN = 6V VOUT = 5V IL = 100mA IL = 100A 25 30 101 102 10 3 104 105 106 INPUT VOLTAGE (V) FREQUENCY (Hz) Rev. 11/2/00 LP2950/LP2951 TYPICAL APPLICATIONS +VIN 100K ERROR OUTPUT 5 8 ______ ERROR +VIN VOUT 1 1.2 to 30V LP2951 + SHUTDOWN INPUT 3 SD GND 4 R1 FB 7 3.3uF .01uF 1.23V VREF R2 Figure 1. Adjustable Regulator +VIN +VIN 470K .. 5 ______ ERROR 8 +VIN VOUT 1 470K .. VOUT ERROR OUTPUT 5 8 ______ ERROR +VIN VOUT 1 *VOUT = VIN LP2951 + 3 LP2951 1uF SHUTDOWN INPUT 3 SD GND 4 R1 FB 7 SD GND 4 FB 7 R2 *MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 4mV TO 400mV. DEPENDING ON LOAD CURRENT. CURRENT LIMIT IS TYPICALLY 160mA Fig.2 Latch Off When Error Flag Occurs 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 .. 1N457 8 +VIN VOUT 1 MAIN V- AS385 LP2951 FOR 5.5 V 400K .. 3 100K .. SD GND 4 SENSE MEMORY V+ 2 + 1uF 20K .. NI-CAD BACKUP BATTERY Fig.4 Low Battery Disconnect 39k .. RESET C4 + 8 +VIN 5 ______ ERROR 2 SENSE VOUT 1 +VOUT = 5V + 1uF 3 LP2951 SD FB 7 39k .. GND 4 TAP 6 1% 100k .. C1 + 100k .. 6V LEADACID BATTERY 1% 1k .. C2 + <5.8V** 100k .. <6.0V** 1% 1k .. C3 + 100k .. <6.2V** R3 10k .. * 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 1% 20k .. Fig. 5 Regulator with State-of-Charge Indicator Rev. 11/2/00 LP2950/LP2951 TYPICAL APPLICATIONS (continued) +VIN 8 AUX SHUTDOW INPUT OFF ON 3 +VIN SD 10K .. _______ 5 ERROR 5 DEGREE SHUTDOWN FLAG LP2951 VOUT GND + 1 FB 7 4 TEMP SENSOR 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 20mA 8 +V IN VOUT 1N4001 1 5 4.7mA UNREGULATED INPUT OUTPUT 330K .. 27K IN VOUT 1 2N5432 LP2951 FB GND 4 0.1uF 7 2 3 LP2951 VTAP FB 7 .. 5V 360K 1N457 MIN VOLTAGE = 4V .. SENSE GND 4 2 + OUTPUT 4.7uF LOAD 50mA TO 300 mA Fig. 7 Open Circuit Detector for 4mA to 20mA Current Loop 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 1% 1% 1% 1% 0.5% 0.5% 0.5% 0.5% 1% 1% 1% 1% 0.5% 0.5% 0.5% 0.5% Output Voltage 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 Packages 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 |
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