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| LP2950/LP2951 100mA Low Dropout Voltage Regulators * 5.0V and 3.3V Versions at 100mA Output * Very Low Quiescent Current * Low Dropout Voltage: 380mV at 100mA * Extremely Tight Load and Line Regulation * Very Low Temperature Coefficient * Current & Thermal Limiting * Need Only 1 F for Stability * Offered in TO-92 (LP2950) & SOIC (LP2951) * Direct Replacement For LP2950/LP2951 FEATURES * 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 APPLICATIONS LP2951 versions only * Error Flag Warns of Output Dropout * Logic-Controlled Electronic Shutdown * Output Programmable From 1.24 to 29V Now Available in Lead Free Packaging 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 feature low quiescent current and low dropout voltage (typ. 50mV at light load and 380 mV at 100mA). This includes a tight initial tolerance (0.5% typ.), extremely good load and line regulation (0.05% typ.), and very low output temperature coefficient (20 ppm/C typ.), making the LP2950/LP2951 useful as a low-power voltage reference. The error flag output feature is used as a power-on reset for warning of a low output voltage, due to a falling input voltage. The logiccompatible shutdown feature enables the regulator to be switched ON and OFF. The LP2950 is offered in a 3-pin TO-92 package compatible with other 5V, 3.3V regulators. The LP2951 is available in an 8-lead SOIC package. Block diagram of LP2951 UNREGULATED DC + 7 FEEDBACK 8 INPUT 1 OUTPUT 5V @ 100mA MAX 2 SENSE + _ FROM CMOS OR TTL 180k 6 ERROR AMPLIFIER 5V TAP 3 SHUTDOWN 60 mV 330k + 60k + 5 ______ ERROR + _ ERROR DETECTION COMPARATOR 1F . . TO CMOS OR TTL + 1.23V 4 REFERENCE GROUND Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 1 (c)Copyright 2001 Sipex Corporation 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 -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 VIN=6V, IO=100A, COUT=1F (Note 2) TA=25C, unless otherwise noted. PARAMETER 3.3 V Versions Output Voltage CONDITIONS LP2950AC LP2951AC Min. Typ. Max. 3.284 3.267 3.260 3.254 3.3 3.3 3.3 3.3 3.317 3.333 3.340 3.346 Min. 3.267 3.251 3.234 3.221 LP2950C LP2951C Typ. Max. 3.3 3.3 3.3 3.3 3.333 3.350 3.366 3.379 UNITS V 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 Output Voltage 5 V Versions Output Voltage V 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 4.975 4.950 4.940 4.925 5.0 5.0 5.0 5.0 5.025 5.050 5.060 5.075 4.950 4.925 4.900 4.880 5.0 5.0 5.0 5.0 5.050 5.075 5.100 5.120 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 = 3.3 F, Bypass = 0.01F from Pin 7 to Pin 1 (LP2951) 0.03 0.04 50 380 150 8 150 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 8 150 0.05 430 160 100 150 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 Over Temperature (Note 6) 1.220 1.190 LP2951AC 1.235 1.250 1.270 1.210 1.185 LP2951C 1.235 1.260 1.285 V V Feedback Pin Bias Current 40 60 40 60 nA Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 2 (c)Copyright 2001 Sipex Corporation 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 Shut down Pin Input Current Regulator Output Current in Shutdown Low (Regulator ON) High (Regulator OFF) VS = 2.4V VS= 30V (Note 8) 1.3 2.0 30 675 3 50 800 10 0.7 2.0 30 675 3 50 800 10 1.3 0.7 V V A A A VOH = 30V VIN = 4.5V IOL = 400A (Note 7) (Note 7) (Note 7) CONDITIONS (Note 2) Min. LP2951AC Typ. Max. 20 Min. LP2951C Typ. Max. 50 UNITS ppm/C 0.1 0.1 nA/C 0.01 150 40 60 75 15 1 250 40 95 0.01 150 60 75 15 1 250 A mV mV 95 mV mV 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 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 100mA, 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. Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 3 (c)Copyright 2001 Sipex Corporation LP2950/ LP2951 TYPICAL PERFORMANCE CHARACTERISTIC 6 5 OUTPUT VOLTAGE (VOLTS) INPUT CURRENT (A) 250 225 R L = 50k 10 4 R L= 175 150 125 100 75 50 25 0 GROUND PIN CURRENT (mA) 200 1 3 R L =50k 8 2 1 0 0 1 2 3 4 5 6 INPUT VOLTAGE (VOLTS) RL = 8 0.1 0 1 2 3 4 5 6 7 8 9 10 0.01 0.1 1 10 100 INPUT VOLTAGE (VOLTS) LOAD CURRENT (mA) Dropout Characteristics Input Current Quiescent Current 320 280 GROUND CURRENT (A) INPUT CURRENT (mA) 240 200 160 IL= 0 I L = 1mA 120 80 40 0 0 1 2 3 4 5 6 7 8 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 16 GROUND CURRENT (mA) R L =50 VOUT = 5V 12 V IN = 6V I L = 100mA 8 4 7 8 9 10 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) INPUT VOLTAGE (VOLTS) INPUT VOLTAGE (VOLTS) Ground Current 16 14 Input Current 190 Ground Current QUIESCENT CURRENT (A) GROUND CURRENT (mA) 12 I L =100mA 170 V IN =6V I L =100uA 10 8 6 4 2 0 0 1 2 3 4 5 6 7 8 150 130 -75 -50 -25 0 25 50 75 100 125 150 INPUT VOLTAGE TEMPERATURE (C) Ground Current Quiescent Current Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 4 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) 600 I L = 100mA 500 170 160 SHORT CIRCUIT CURRENT (mA) 500 DROP-OUT VOLTAGE (mV) DROP-OUT VOLTAGE (mV) 400 150 140 130 120 110 110 -75 -50 -25 400 300 ~ ~ 300 200 TJ = 25C 100 50 0 -75 -50 -25 0 25 50 75 100 125 150 I L = 100A 100 0 100A 1mA 10mA 100mA 0 25 50 75 100 125 150 TEMPERATURE (C) OUTPUT CURRENT TEMPERATURE (C) Drop-Out Voltage 8 V OUT = 5V Drop-Out Voltage 2.5 T A = 125C Short Circuit Current 100 mV 50 mV INPUT OUTPUT VOLTAGE VOLTAGE CHANGE 6 COMPARATOR OUTPUT (V) SINK CURRENT (mA) 2.0 4 HYSTERESIS 0 -50 mV ~ ~ 8V 6V 4V 0 200 400 TIME(s) C L = 1F I L = 1mA V OUT = 5V 1.5 T A = 25C 2 0 -2 0 1 PULLUP RESISTOR TO SEPARATE 5V SUPPLY 1.0 T A = -55C 0.5 0.0 2 3 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) INPUT VOLTAGE (V) 600 800 Error Comparator Output 10 IO = 100A LP2951 Comparator Sink Current 90 80 RIPPLE REJECTION (dB) Line Transient Response 90 80 RIPPLE REJECTION (dB) C L = 1F V IN = 6V V OUT = 5V OUTPUT IMPEDANCE (OHMS) 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 10 100 1K 10K 100K 1M FREQUENCY (Hz) V OUT = 5V C L = 1F I O = 1mA I O = 100mA 70 IL = 0 70 60 50 40 30 20 I L = 1mA 60 50 40 30 20 10 1 C L = 1F V IN = 6V V OUT = 5V I L = 100A I L = 10mA 10 2 10 3 10 4 10 5 10 6 10 1 10 2 10 3 10 4 10 5 10 6 FREQUENCY (Hz) FREQUENCY (Hz) Output Impedance Ripple Rejection Ripple Rejection Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 5 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL PERFORMANCE CHARACTERISTICS (continued) 2.3 20 50 0 FEEDBACK CURRENT (A) PIN 7 DRIVEN BY EXTERNAL SOURCE (REGULATOR RUN OPEN LOOP) MINIMUM OPERATING VOLTAGE (V) 10 BIAS CURRENT (nA) 2.1 -50 -100 -150 -200 -250 TA=1 25C 0 -10 1.9 T A = 25C T A = 55C -20 1.7 -75 -30 -50 -25 0 25 50 75 100 125 150 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE TEMPEATURE (C) -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 FEEDBACK VOLTAGE (V) LP2951 Minimum Operating Voltage LP2951 Feedback Bias Current LP2951 Feedback Pin Current 250 200 150 LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) LOAD OUTPUT VOLTAGE CURRENT CHANGE (mV) 80 60 40 20 0 -20 -40 -60 ~ ~ C L = 10F V OUT = 5V 7 6 SHUTDOWN OUTPUT PINOUT VOLTAGE (V) VOLTAGE (V) C L = 1F 5 4 3 2 1 0 2 0 -2 -100 0 100 200 300 400 500 600 700 TIME (us) C L = 10F I L = 10mA V IN = 8V V OUT = 5V 100 50 0 -50 -100 ~ ~ C L = 1F V OUT = 5V 100 A mA 100 100 0 1 2 TIME (ms) A A 100 3 4 5 0 4 8 12 16 20 TIME (ms) Load Transient Response Load Transient Response Enable Transient 120 100 OUTPUT CURRENT (mA) TO-92 PACKAGE 0.25" LEADS SOLDERED TO PC BOARD Vout=5V T JMAX = 125 C 400 120 8-PIN MOLDED PIN 2 TO PIN 4 RESISTANCE (k) 100 300 OUTPUT CURRENT (mA) 80 60 40 20 0 0 5 10 15 T A = 85 C 80 60 DIP SOLDERED TO PC BOARD T JMAX = 125 C V OUT = 5V 200 T A = 25C T A =25 C 40 20 T A = 50C T A = 85C 100 0 20 25 30 -75 -50 -25 0 25 50 75 100 125 150 0 0 5 10 15 20 25 30 INPUT VOLTAGE (V) TEMPERATURE (C) INPUT VOLTAGE (V) LP2950 Maxium Rated Output LP2951 Divider Resistance LP2950 Maxium Rated Output Current Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 6 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL APPLICATIONS 1.8 SHUTDOWN THRESHOLD VOLTAGE (V) OUTPUT VOLTAGE CHANGE (mV) 5 VOLTAGE NOISE SPECTRAL DENSITY (V/Hz) 3.5 3.0 I L = 100mA C L = 1F 1.6 1.4 1.2 1.0 0.8 0.6 -75 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (1/4C) 4 2 0 -2 2.5 C L = 220F 2.0 1.5 1.0 0.5 0.0 C L = 3.3F C BYP = 0.1F POWER DISSIPATION (W) ~ ~ 1 1.25W 0 -1 0 10 20 30 40 50 TIME (s) 10 2 10 3 10 4 10 5 FREQUENCY (Hz), C BYP =0.1uF Shutdown Threshold Voltage Thermal Response Output Noise 30 OUTPUT VOLTAGE CHANGE (mV) 80 I L = 50A I L = 100A RIPPLE REJECTION (dB) 25 20 15 10 5 0 ~ ~ 10 5 0 -5 -10 5 10 15 20 T J = 125 1/4C T J = 150 1/4C 70 60 50 40 30 20 10 C L = 1F V IN = 6V V OUT = 5V I L = 100mA I L = 1mA I L = 100A 25 30 10 1 10 2 10 3 10 4 10 5 10 6 INPUT VOLTAGE (V) FREQUENCY (Hz) Line Regulation Ripple Rejection Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 7 (c)Copyright 2001 Sipex Corporation LP2950/51 APPLICATION HINTS EXTERNAL CAPACITORS The stability of the LP2950/LP2951 requires a 1.0F 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 500kHz 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 10mA the value of the capacitor can be reduced to 0.33 F and 0.1 F for 1mA. 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 100mA 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 100pF capacitor between output and feedback and increasing the output capacitor to at least 3.3 F. 4.75V OUTPUT VOLTAGE remains 5% below normal regardless of the programmed output voltage of the regulator. 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 LP2951Os 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 400 A, 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 20nA. The minimum recommended load current of 1 A forces an upper limit of 1.2M 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 R 1. To improve the accuracy choose the value of R2 = 100k this reduces the error by 0.17% and increases the resistor program current by 12A. Since the LP2951 typically draws 60A 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 1F to 220 F only decreases the noise from 430V to 160VRMS for a 100kHz bandwidth at 5V output. Noise could also be reduced fourfold by a bypass capacitor across R 1, since it reduces the high frequency gain from 4 to unity. Pick \ _______ ERROR* +5.0V INPUT VOLTAGE + + +1.3V CBYPASS 1 / 2R1 x 200 Hz or choose 0.01F. When doing this, the output capacitor must be increased to 3.3F to maintain stability. These changes reduce the output noise from 430V to 100VRMS for a 100kHz 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 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 Rev. 8/10/01 9 LP2950/51 100mA Low Dropout Voltage Regulators 8 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL APPLICATIONS +V IN 100K ERROR OUTPUT 5 8 ______ ERROR +V IN V OUT 1 1.2 to 30V LP2951 SHUTDOWN INPUT 3 SD GND 4 R1 FB 7 + 3.3F .01F 1.23V V REF R2 Figure 2. Adjustable Regulator +V IN 470k 5 8 +V IN ______ ERROR +V IN 470k V OUT 1 V OUT ERROR 5 8 LP2951 + 3 OUTPUT ______ ERROR +V IN V OUT 1 *V OUT = V IN SD GND 4 R1 FB 7 1F SHUTDOWN INPUT 3 LP2951 SD GND 4 RESET FB 7 R2 *MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40mV to 400mV. DEPENDING ON LOAD CURRENT. CURRENT LIMIT IS TYPICALLY 150mA Figure 3. Latch Off When Error Flag Occurs Figure 4. Wide Input voltage Range Current Limiter Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 9 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL APPLICATIONS (continued) + 6V SEALED LEADACID BATTERY SOURCE 120k FB 1.5k 1N457 8 +V IN 1 SPX385 V OUT MAIN V+ LP2951 FOR 5.5 V 400k 3 100k SD GND 4 SENSE 2 + MEMORY V+ 1F 20k NI-CAD BACKUP BATTERY Figure 5. 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 + 100k .. <5.8V** 1% 1k .. C3 + 100k .. <6.0V** R3 10k .. <6.2V** * 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 .. Figure 6. Regulator with State-of Charge Indicator Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 10 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 TYPICAL APPLICATIONS (continued) +V IN 8 AUX SHUTDOW INPUT ON OFF 3 +V IN SD 10K . _______ ERROR 5 5 DEGREE SHUTDOWN FLAG . LP2951 V OUT GND + 1 FB 7 4 TEMP SENSOR AS35 - EXTERNAL CIRCUIT PROTECTED FROM OVER TEMPERATURE (V+ GOES OFF WHEN TEMP > 125) OR RELAY 8.2K Figure 7. System Over Temperature Protection +5V 4 20mA 8 +V IN V OUT 1N4001 1 4.7mA UNREGULATED INPUT OUTPUT 8 IN V OUT 1 330K 27K 2N5432 (2) LP2951 LP2951 FB 7 2 6 2 0.1F V TAP FB 7 SENSE GND 4 + 5V OUTPUT 4.7F LOAD 50mA TO 300 mA GND 4 1N457 MIN VOLTAGE = 4V 360K Figure 8. Open Circuit Detector for 4mA to 20mA Current Loop Figure 9. 300mA Regulator with 0.75V Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 11 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 SCHEMATIC DIAGRAM Rev. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 12 (c)Copyright 2001 Sipex Corporation LP2950/LP2951 PACKAGE DIAGRAM 8-Pin Surface Mount (S) 1 OUTPUT SENSE SHUTDOWN GROUND 1 2 8 TO-92 (N) 2 3 INPUT FEEDBACK 5V or 3.3V Output ERROR ALPHA 7 6 5 3 AS293 40 V OUT VIN GROUND LP2951 Top View LP2950 Bottom View ORDERING INFORMATION Ordering No. LP2950ACN-3.3 LP2950ACN-5.0 LP2950CN-3.3 LP2950CN-5.0 LP2951ACS-3.3 LP2951ACS-5.0 LP2951CS-3.3 LP2951CS-5.0 Accuracy 0.5% 0.5% 1% 1% 0.5% 0.5% 1% 1% Output Voltage 3.3V 5.0V 3.3V 5.0V 3.3V 5.0V 3.3V 5.0V Packages 3 lead TO-92 3 lead TO-92 3 lead TO-92 3 lead TO-92 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC 8 Lead SOIC Corporation Now available in Lead Free. To order ad "-L" to the part number. Example: LP2950CN= Normal, LP2950CN-L = Lead Free 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. 8/10/01 LP2950/51 100mA Low Dropout Voltage Regulators 13 (c)Copyright 2001 Sipex Corporation |
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