LT1020IS

LT1020 Micropower Regulator and Comparator FEATURES s s s s s s s s s s DESCRIPTIO 40µA Supply Current 125mA Output Current 2.5V Reference Voltage Reference Output Sources 1mA and Sinks 0.5mA Dual Output Comparator Comparator Sinks 10mA Dropout Detector 0.2V Dropout Voltage Thermal Limiting Available in SO Package The LT1020 is a combination micropower positive regulator and free collector comparator on a single monolithic chip. With only 40µA supply current, the LT1020 can supply over 125mA of output current. Input voltage range is from 4.5V to 36V and dropout voltage is 0.6V at 125mA. Dropout voltage decreases with lower load currents. Also included on the chip is a class B output 2.5V reference that can either source or sink current. A dropout detector provides an output current to indicate when the regulator is about to drop out of regulation. The dual output comparator can be used as a comparator for system or battery monitoring. For example, the comparator can be used to warn of low system voltage while the dropout detector shuts down the system to prevent abnormal operation. Frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. Dual output or positive and negative regulators can also be made. The 2.5V reference will source or sink current. This allows it to be used as a supply splitter or auxiliary output. APPLICATI s s s s S Battery Systems Battery Backup Systems Portable Terminals Portable Instruments TYPICAL APPLICATI 5V Regulator Dropout Voltage and Supply Current 1 10 LT1020 0.001µF FB 11 + 1M + 10µF GND 9 10µF DROPOUT VOLTAGE (V) VIN > 5.2V IQ = 40µA 3 VIN VOUT 2 5V SUPPLY CURRENT (mA) 1M 1020 TA01 0.1 0.01 0.1 U 1 10 1 100 OUTPUT CURRENT (mA) 0.1 1000 1020 TA02 UO UO 1 LT1020 ABSOLUTE AXI U RATI GS Operating Temperature Range LT1020C ............................................. 0°C to 100°C LT1020I ........................................ – 40°C to 100 °C LT1020M ....................................... – 55°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C Input Voltage .......................................................... 36V NPN Collector Voltage ............................................ 36V PNP Collector Voltage.............................. Supply – 36V Output Short Circuit Duration ......................... Indefinite Power Dissipation.............................. Internally Limited Storage Temperature Range ................ – 65°C to 150°C PACKAGE/ORDER I FOR ATIO TOP VIEW NC VOUT VIN REF OUT COMP PNP COMP NPN +INPUT 1 2 3 4 5 6 7 14 NC DROPOUT 13 DETECTOR 12 SHUTDOWN 11 FEEDBACK CURRENT 10 LIMIT 9 GND 8 –INPUT ORDER PART NUMBER LT1020CJ LT1020CN LT1020IJ LT1020IN LT1020MJ J PACKAGE 14-LEAD CERAMIC DIP N PACKAGE 14-LEAD PLASTIC DIP TJMAX = 150° C, θJA = 80°C/W (J) TJMAX = 110°C, θJA = 130°C/W (N) ELECTRICAL CHARACTERISTICS PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Temperature Stability Regulator Supply Current CONDITIONS TJ = 25°C MIN 2.46 TYP 2.50 0.01 0.2 4 2 1 45 75 11 125 0.2 0.01 0.02 0.4 2.5 20 0.5 0.015 0.05 0.65 2.56 MAX 2.54 0.015 0.3 UNITS V %/V % mA mA % µA µA mA mA % %/V V V V µA 4.5V ≤ VIN ≤ 36V 4.5V ≤ VIN ≤ 36V – 0.5mA ≤ IREF ≤ 1mA, VIN = 12V VIN = 5V VIN = 5V Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current VIN = 6V, IOUT ≤ 100µA VIN = 36V, IOUT ≤ 100µA VIN = 12V, IOUT = 125mA (VIN – VOUT) ≥ 1V, VIN ≥ 6V (VIN – VOUT) ≥ 1V, VIN ≥ 6V 6V ≤ VIN ≤ 36V IOUT = 100µA IOUT = 125mA VIN = 12V ∆VOUT = – 0.05V, IOUT = 500µA 2 U U W WW U W TOP VIEW NC 1 VOUT 2 VIN 3 REF OUT 4 COMP PNP 5 COMP NPN 6 +INPUT 7 NC 8 16 NC 15 DROPOUT DETECTOR 14 SHUTDOWN 13 CURRENT LIMIT 12 FEEDBACK 11 GND 10 –INPUT 9 NC ORDER PART NUMBER LT1020CS LT1020IS S PACKAGE 16-LEAD PLASTIC SOIC TJMAX = 110°C, θJA = 150°C/W 1 0.5 80 120 20 2.44 3 LT1020 ELECTRICAL CHARACTERISTICS PARAMETER Regulator Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down Common-Mode Rejection Power Supply Rejection Output Sink Current NPN Saturation Voltage Output Source Current Input Voltage Range Response Time Leakage Current (NPN) CONDITIONS TJ = 25°C MIN TYP 15 1 300 30 3 15 4 10000 94 96 18 0.4 200 5 2 MAX 40 5 400 UNITS nA µA mA mA mV nA nA V/ V dB dB mA V µA V µs µA VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V ∆VOUT = 29V, RL = 20k 0V ≤ VCM ≤ 35V, VIN = 36V 4.5V ≤ VS ≤ 36V VIN = 4.5V IOUT = 1mA 3 7 40 15 2000 80 80 10 60 0 0.6 VIN – 1 ELECTRICAL CHARACTERISTICS PARAMETER Reference Reference Voltage Line Regulation Load Regulation Output Source Current Output Sink Current Regulator Supply Current CONDITIONS 4.5V ≤ VIN ≤ 36V 4.5V ≤ VIN ≤ 36V – 0.5mA ≤ IREF ≤ 1mA, VIN = 12V VIN = 5V VIN = 5V VIN = 6V, IOUT ≤ 100µA VIN = 36V, IOUT ≤ 100µA VIN = 12V, IOUT = 125mA (VIN – VOUT) ≥ 1V, VIN ≥ 6V (VIN – VOUT) ≥ 1V, VIN ≥ 6V 6V ≤ VIN ≤ 36V IOUT = 100µA IOUT = 125mA VIN = 12V ∆VOUT = – 0.05V, IOUT = 500µA VIN = 36V VIN = 36V Pins 9 and 10 Shorted, VIN = 4.5V 0V ≤ VCM ≤ 35V, VIN = 36V 0V ≤ VCM ≤ 35V, VIN = 36V (Note 1) 0V ≤ VCM ≤ 35V, VIN = 36V ∆VOUT = 29V, RL = 20k q q q q q q q q q q q q q q q q q q q q q q q MIN 2.40 TYP 2.50 0.01 0.3 MAX 2.55 0.02 0.4 UNITS V %/V % mA mA µA µA mA mA % %/ V V V V µA nA µA mA mA mV nA nA V/ V 1 0.5 65 85 11 125 1 0.02 0.06 0.85 2.57 50 50 400 95 120 20 Output Current Load Regulation Line Regulation Dropout Voltage Feedback Sense Voltage Dropout Detector Current Feedback Bias Current Minimum Load Current Short-Circuit Current Comparator Offset Voltage Bias Current Offset Current Gain-NPN Pull-Down 2.38 3 2.5 2.5 300 30 15 1000 10 60 20 3 LT1020 ELECTRICAL CHARACTERISTICS PARAMETER Comparator Common-Mode Rejection Power Supply Rejection Output Sink Current Output Source Current Input Voltage Range Leakage Current (NPN) CONDITIONS 0V ≤ VCM ≤ 35V, VIN = 36V 4.5V ≤ VIN ≤ 36V VIN = 4.5V (Note 2) q q q q q MIN 80 80 5 40 0 TYP MAX UNITS dB dB mA µA V µA 10 120 VIN – 1 8 VIN = 36V q The q denotes specifications which apply over the full operating temperature range. Note 1: For 0V ≤ VCM ≤ 0.1V and T > 85°C IBIAS(MAX) is 100nA. Note 2: For TA ≤ – 40°C output ISINK(MIN) is 2.5mA. TYPICAL PERFOR A CE CHARACTERISTICS Regulator Load Regulation 0.3 PRELOAD = 100µA OUTPUT VOLTAGE CHANGE (%) SUPPLY CURRENT (mA) TJ = – 55°C 0.1 0 –0.1 –0.2 –0.3 0.1 TJ = 125°C TJ = 25°C 10 SHORT-CIRCUIT CURRENT (mA) 0.2 1 10 100 OUTPUT CURRENT (mA) Dropout Voltage REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) ∆VOUT = 100mV REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1 INPUT/OUTPUT DIFFERENTIAL (V) 0.1 0.01 0.1 1 100 10 1000 REGULATOR OUTPUT CURRENT (mA) 1020 G04 4 UW 1020 G01 Supply Current 100 TJ = – 55°C TO 125°C Regulator Short-Circuit Current 350 300 250 200 150 100 50 0 –50 CURRENT LIMIT TIED TO GROUND 1 0.1 1000 0.01 0.1 10 100 1000 1 REGULATOR OUTPUT CURRENT (mA) 1020 G02 –10 70 110 30 TEMPERATURE (°C) 150 1020 G03 Dropout Voltage 1 DROPOUT DETECTOR = 5µA 1 Dropout Voltage I DROPOUT DETECTOR = 0.1% IOUT 0.1 0.1 I DROPOUT DETECTOR = 1% IOUT 0.01 0.1 0.01 1 100 10 1000 REGULATOR OUTPUT CURRENT (mA) 1020 G05 0.1 1 10 100 REGULATOR OUTPUT CURRENT (mA) 1020 G06 LT1020 TYPICAL PERFOR A CE CHARACTERISTICS Dropout Detector Current 100 DROPOUT DETECTOR CURRENT (µA) 1000 DROPOUT DETECTOR CURRENT (µA) MINIMUM LOAD CURRENT (µA) VDIFF = 500mV 10 1 0.1 VDIFF = 1V 0.01 10 100 REGULATOR OUTPUT CURRENT (mA) 1000 Regulator Ripple Rejection 70 65 IOUT = 100mA IOUT = 10mA SUPPLY CURRENT (mA) 1 10 RIPPLE REJECTION (dB) SUPPLY CURRENT (mA) 60 55 IOUT = 1mA 50 45 40 35 30 10 VIN = 100VDC, 1VP-P VOUT = 5V COUT = 10µF 10k 100 1k RIPPLE FREQUENCY (Hz) Reference Regulation 4 REFERENCE VOLTAGE CHANGE (mV) 3 INPUT BIAS CURRENT (nA) 2 1 0 –1 –2 –3 –4 –1.5 0.5 1.0 –1.0 –0.5 0 REFERENCE OUTPUT CURRENT (mA) 1.5 80 70 60 50 40 30 20 10 0 –1.0 FEEDBACK PIN CURRENT (nA) UW 1020 G07 1020 G10 Dropout Detector Current 100 IOUT = 100mA 100 IOUT = 25mA Regulator Minimum Load Current 10 10 IOUT = 5mA IOUT = 1mA 1 0 0.2 0.3 0.4 0.5 0.6 0.1 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G08 1 70 80 90 100 110 120 130 140 TEMPERATURE (°C) 150 1020 G09 Supply Current 10 Supply Current at Dropout TJ = – 55°C TO 125°C IOUT = 100mA IOUT = 100mA 1 IOUT = 10mA 0.1 IOUT = 10mA 0.1 IOUT = 1mA VOUT = 5V TJ = – 55°C TO 125°C IOUT = 1mA 100k 0.01 1 10 15 20 25 5 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G11 0.01 0.2 0.3 0.4 0.5 0.6 0.1 0 REGULATOR INPUT/OUTPUT DIFFERENTIAL (V) 1020 G12 Comparator Input Bias Current 100 90 TJ = 125°C TJ = 25°C TJ = – 55°C 40 35 30 25 20 15 10 5 0 Feedback Pin Current TJ = – 55°C TJ = 25°C TJ = 125°C 1020 G13 –0.6 0.6 –0.2 GND 0.2 COMMON-MODE VOLTAGE (V) REFERRED TO PIN 9 (GND) 1.0 1020 G14 0.1 100 1000 1 10 REGULATOR OUTPUT CURRENT (mA) 1020 G15 5 LT1020 TYPICAL PERFOR A CE CHARACTERISTICS Regulator Thermal Regulation OUTPUT VOLTAGE CHANGE (%) 0.1 VIN = 15V VOUT = 5V 0 5.5 5.0 VOUT = 5V OUTPUT VOLTAGE (V) –0.1 OUTPUT CURRENT (mA) 50 0 0 20 40 60 80 100 120 140 160 180 TIME (ms) 1020 G16 PI FU CTIO S Pins 1, 14: No internal connection. Pin 2: Regulator Output. Main output, requires 10µF output capacitor. Can be shorted to VIN or ground without damaging the device. Pin 3: Input Supply. Bypass with 10µF capacitor. Must always be more positive than ground. Pin 4: Reference. 2.5V can source or sink current. May be shorted to ground or up to 5V. Voltages in excess of 5V can damage the device. Pin 5: Comparator PNP Output. Pull-up current source for the comparator. May be connected to any voltage from VIN to 36V more negative than VIN (operates below ground). Short-circuit protected. For example, if VIN is 6V then pin 5 will operate to – 30V. Pin 6: Comparator NPN Output. May be connected to any voltage from ground to 36V more positive than ground (operates above VIN). Short-circuit protected. Pins 7, 8: Comparator Inputs. Operates from ground to VIN – 1V. Comparator inputs will withstand 36V even with VIN of 0V. Pin 9: Ground. Pin 10: Current Limit. Connecting this pin to ground decreases the regulator current limit to 3mA minimum. Leave open when not used. Pin 11: Feedback. This is the feedback point of the regulator. When operating, it is nominally at 2.5V. Optimum source resistance is 200k to 500k. The feedback pin should not be driven below ground or more positive than 5V. Pin 12: Shutdown. Turns output off. Pin 13: Dropout Detector. This pin acts like a current source from VIN which turns on when the output transistor goes into saturation. The magnitude of the current depends on the magnitude of the output current and the input/output voltage differential. Pin current ranges from 5µA to about 300µA. 6 UW LT1020 Turn-On Characteristic 4.5 4.0 3.5 3.0 2.5 2.0 0 0 1 2 5 6 3 4 INPUT VOLTAGE (V) 7 8 NO LOAD RL = 50Ω RL = 500Ω 1020 G17 U U U LT1020 BLOCK DIAGRA W REF OUT 4 10 CURRENT LIMIT 3 VIN PNP OUT NPN OUT 5 6 2 13 VOUT DROPOUT DETECTOR 7 8 9 GND 1020 BD NONINVERTING INVERTING APPLICATI S I FOR ATIO The LT1020 is especially suited for micropower system applications. For example, the comparator section of the LT1020 may be used as a battery checker to provide an indication of low battery. The dropout detector can shut down the system when the battery voltage becomes too low to regulate. Another type of system application for the LT1020 would be to generate the equivalent of split supplies from a single power input. The regulator section provides regulated output voltage and the reference, which can both source and sink current, is then an artificial system ground providing a split supply for the system. For many applications the comparator can be frequency compensated to operate as an amplifier. Compensation values for various gains are given in the data sheet. The comparator gain is purposely low to make it easier to frequency compensate as an amplifier. Two outputs are available on the comparator, the NPN output is capable of sinking 10mA and can drive loads connected to voltages in excess of the positive power supply. This is useful for driving switches or linear regulators from a higher input voltage. The PNP output, which is capable of sourcing 100µA can drive loads below ground. It can be used to make negative regulators with the addition of an external pass transistor. Both outputs can be tied together to provide an output that swings from rail-to-rail for comparator or amplifier applications. Although it is not specified, the gain for the PNP output is about 500 to 1000. U – + REF 2.5V 11 FB W U UO If the PNP output is being used, to maximize the gain a 1µA to 5µA load should be placed upon the NPN output collector. This is easily done by connecting a resistor between the NPN collector and the reference output. (Providing this operating current to the NPN side increases the internal emitter base voltages and maximizes the gain of the PNP stage.) Without this loading on the NPN collector, at temperatures in excess of 75°C, the gain of the PNP collector can decrease by a factor of 2 or 3. Reference Internal to the LT1020 is a 2.5V trimmed class B output reference. The reference was designed to be able to source or sink current so it could be used in supply splitting applications as well as a general purpose reference for external circuitry. The design of the reference allows it to source typically 4mA or 5mA and sink 2mA. The available source and sink current decreases as temperature increases. It is sometimes desirable to decrease the AC output impedance by placing an output capacitor on them. The reference in the LT1020 becomes unstable with large capacitive loads placed directly on it. When using an output capacitor, about 20Ω should be used to isolate the capacitor from the reference pin. This 20Ω resistor can be placed directly in series with the capacitor or alternatively the reference line can have 20Ω placed in series with it and then a capacitor to ground. This is shown in Figure 1. Other than placing large capacitive loads on the reference, no 7 LT1020 APPLICATI S I FOR ATIO other precautions are necessary and the reference is stable with nominal stray capacitances. REF 4 OUTPUT 20Ω OR 10µF REF 4 20Ω OUTPUT + + 10µF 1020 F01 Figure 1. Bypassing Reference Overload Protection The main regulator in the LT1020 is current limited at approximately 350mA. The current limit is stable with both input voltage and temperature. A current limit pin, when strapped to ground, decreases the output current. This allows the output current to be set to a lower value than 250mA. The output current available with the current limit pin strapped to ground is not well controlled so if precise current limiting is desired it should be provided externally as is shown in some of the application circuits. If the device is overloaded for long periods of time, thermal shutdown turns the output off. In thermal shutdown, there may be some oscillations which can disturb external circuitry. A diode connected between the reference and feedback terminal provides hysteresis under thermal shutdown, so that the device turns on and off with about a 5 second period and there are no higher frequency oscillations. This is shown in Figure 2. This diode is recommended for most applications. Thermal shutdown temperature is set at approximately 145°C. 2 0.001µF FB 11 VOUT LT1020 REF 4 * * DIODE ADDS FEEDBACK + 10µF 1020 F02 Figure 2. Minimizing Oscillation in Thermal Shutdown 8 U Like most other IC regulators, a minimum load is required on the output of the LT1020 to maintain regulation. For most standard regulators this is normally specified at 5mA. Of course, for a micropower regulator this would be a tremendously large current. The output current must be large enough to absorb all the leakage current of the pass transistor at the maximum operating temperature. It also affects the transient response; low output currents have long recovery times from load transients. At high operating temperatures the minimum load current increases and having too low of a load current may cause the output to go unregulated. Devices are tested for minimum load current at high temperature. The output voltage setting resistors to the feedback terminal can usually be used to provide the minimum load current. Frequency Compensation The LT1020 is frequency compensated by a dominant pole on the output. An output capacitor of 10µF is usually large enough to provide good stability. Increasing the output capacitor above 10µF further improves stability. In order to insure stability, a feedback capacitor is needed between the output pin and the feedback pin. This is because stray capacitance can form another pole with the large value of feedback resistors used with the LT1020. Also, a feedback capacitor minimizes noise pickup and improves ripple rejection. With the large dynamic operating range of the output current, 10000:1, frequency response changes widely. Low AC impedance capacitors are needed to insure stability. While solid tantalum are best, aluminum electrolytics can be used but larger capacitor values may be needed. The CURRENT LIMIT pin allows one of the internal nodes to be rolled off with a 0.05µF capacitor to ground. With this capacitor, lower values of regulator output capacitance can be used (down to 1µF) for low ( 5.2V IQ = 40µA 3 VIN LT1020 DROPOUT 500k TO 2M 3M 1020 TA04 Regulator with Improved Transient Response 7 VIN > 5.2V 3 VIN LT1020 GND 9 VOUT 2 0.001µF 1M FB 11 0.001µF 22k 1M UO S Regulator with Output Voltage Monitor 3 VIN – LT1020 VOUT 2 0.001µF 11 5V 100k + 8 REF 7 4 2.5V + 100k FB GND 9 10µF 20k 1M 1020 TA03 5V Regulator VOUT LT1020 2 0.001µF FB 11 1M 1020 TA07 5V 1M + + 10µF GND 9 10µF Compensating the Comparator As an Op Amp + 5 5V 8 – 1M 6 + AT AV = 100, SLEW RATE = 0.05V/µs –6V/µs 10µF R2 C2 1020 TA08 R1 C1 AV 1 10 100 R1 33Ω 100Ω 10k C1 C2 0.1µF 0.001µF 0.047µF – 0.002µF – R2 – 100k 10k 1020 TA05 9 LT1020 TYPICAL APPLICATI VIN 2.2k 9 GND 8 –INPUT 1 Amp Low Dropout Regulator 3 VIN LT1020 GND 9 CL 10 0.01µF FB 11 150Ω* 100k VOUT 2 * 10k* MJE2955 VOUT 5V 220µF† 100k SEE LT1129 DATA SHEET FOR 700mA OUTPUT Maintaining Lowest IQ at Dropout 3 2 0.001µF 1M VIN LT1020 GND 9 VOUT 11 DROPOUT FB 13 2N3904* 1M NC 1M * TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS 1020 TA11 2N2907 12VOUT 0.01µF 190k 6 + 10µF 10 UO S Dual Output Regulator VIN > 5.2V 3 VIN VOUT LT1020 REF OUT 4 COMP FB 11 NPN 6 100k 500k 2 500k 0.001µF 5V 0.001µF + 5 COMP PNP +INPUT 7 0.001µF 1M + 10µF * FOR CURRENT LIMIT ≈ 1.5A † MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. 1020 TA06 500k + 10µF –5V REG 10mA 2N3904 51k –VIN 1020 TA09 Dual Output 150mA Regulator VIN > 5.2V 9 GND 8 –INPUT 5V 3 VIN VOUT LT1020 REF OUT 4 2 500k 0.001µF 5V + 5 COMP PNP +INPUT 7 0.001µF 200k COMP FB 11 NPN 6 100k 500k + 10µF 10µF 100k + 10µF –5V REG 150mA 2N3904 51k* 4.7k 0.0047µF 51k* –VIN 1020 TA10 2N3904 * FOR TEMPERATURES GREATER THAN 70°C, REDUCE 51k RESISTORS TO 15k. IQ WILL INCREASE. Dual Output Positive Regulator 3 51k VIN VIN ≥ 12.3V 2 0.001µF 11 FB +IN 50k 7 –IN 8 REF 4 GND 9 5 1020 TA12 – LT1020 VOUT 5V 1M + + 1M 10µF LT1020 TYPICAL APPLICATI BATTERY INPUT VIN > 5.2V IQ = 40µA * TRANSISTOR USED BECAUSE OF LOW LEAKAGE CHARACTERISTICS. TO TURN OFF THE OUTPUT OF THE LT1020, FORCE FB (PIN 11) > 2.5V. VIN 3 9 5 6 * VOUT TURNS OFF AT DROPOUT. VOUT TURN ON WHEN: VIN × R2 = 2.5V R1 + R2 UO 3 VIN VIN S Battery Backup Regulator VOUT 5V VOUT LT1020 GND 9 FB 11 50k 2 0.001µF 2 + 1M VOUT LT1020 VIN 3 10µF 11 FB MAIN POWER INPUT GND 9 INTERNAL PARASITIC DIODES OF LT1020 VOUT 1M 1020 TA13 5V Regulator with Shutdown 3 VIN LT1020 GND 9 FB VOUT 2 + 0.001µF 1M 500k 5V 10µF NC LOGIC INPUT 11 100k 2N3904* 1M 1020 TA14 Turn-Off at Dropout R1 1.5M 8 R2 1M – LT1020 VOUT 2 VOUT* 0.001µF 1M + DROPOUT 13 7 1.5M 0.047µF FB REF 4 11 1M + 10µF 1M 1020 TA15 11 LT1020 TYPICAL APPLICATI LT1020 GND 9 FB 100k 8 1.2k 7 ISC SENSE 0.03Ω † MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. 8 7 12 UO – + S Current Limited 1 Amp Regulator 2.2k 0.5Ω* MJE2955 0.22µF VOUT 2 11 270Ω 100k * SETS CURRENT LIMIT BUT INCREASES DROPOUT VOLTAGE BY 0.5V. † MUST HAVE LOW ESR. SEVERAL 100µF CAPACITORS CAN BE PARALLELED. 1020 TA16 VIN 2N3906* 3 VIN 100k + VOUT 5V, 1A 220µF† 1 Amp Regulator with Precision Current Limit VIN 12V 2.2k + MJE2955 4 LT1020 2 11 3 0.22µF 100µF VOUT 5V 1A 220µF† + 100k FB 6 5 9 1N4148 270Ω 100k RL 1020 TA17 Logic Output on Dropout VIN 4 3 – + 6 LT1020 2 1M FB 5 9 13 11 1M 0.001µF VOUT 5V + 10µF 1M VIN “DROPOUT” 0V TTL COMPATIBLE 1020 TA18 LT1020 TYPICAL APPLICATI Charge Pump Voltage Doubler 1M 51k VIN 1N5819 OR EQUIVALENT VOUT 8 0.0033µF 7 – + 3 5 6 9 1M 22k 2N3904 10µF VOUT (NL) ≅ 2VIN – 1V VOUT (5mA) ≅ 2VIN – 3V IQ ≅ 300µA 51k + VOUT (NL) ≅ – (VIN – 1V) VOUT (5mA) ≅ – (VIN – 3V) IQ ≅ 300µA + + UO S Charge Pump Negative Voltage Generator VIN 1M 51k 8 0.0033µF 7 – + 3 5 6 9 1M 22k 2N3904 + 10µF –VOUT 51k 1N5819 OR EQUIVALENT 20µF 1020 TA19 20µF 1020 TA20 13 LT1020 TYPICAL APPLICATI + 10µF + 10µF * VIN MUST BE GREATER THAN THE BATTERY VOLTAGE PLUS 1.3V 7.5V TO 30V VIN 100µF 3.3M 30k 2N3906 2N3904 TO VREF (PIN4) 1.8M 1M 2N2222 2N3904 1k 100k LT1020 COMPARATOR 2M 10k 4mH 3 VIN LT1020 VREF 30k 4 FB 11 0.01µF 220k VOUT 2 VOUT 5V 100mA 22µF SWITCHING REGULATOR OUTPUT POST REGULATOR MAINTAINS LOW IQ (< 100µA) FOR ALL INPUT VOLTAGES SWITCHER EFFICIENCY = 85% POST REGULATOR EFFICIENCY = 82% OVERALL EFFICIENCY = 70% SWITCHING REGULATOR OUTPUT = 2.5 × (1 + RA /RB). FOR A CLEAN OUTPUT FROM THE LINEAR REGULATOR SET TO VOUT + 1.2V 14 UO 51k 6 S 50mA Battery Charger and Regulator VIN* 2N2905 20k 8 220k 4 3 VIN VOUT LT1020 2.5V FB 7 9 11 1M 10µF + – + 2 5V 1M 0.001µF + 10µF 6V BATTERY 3.9Ω 1020 TA21 Switching Preregulator for Wide Input Voltage Range + – 6 8 + 2M 7 RA 1.5M 220k RB 1M 0.001µF + 30k 1020 TA22 100µF REFERENCE 4 3 R35 42k Q19 Q54 Q55 Q14 Q25 Q38 Q52 C5 100pF Q42 Q24 Q29 Q40 Q43 125k Q44 Q31 C2 25pF Q30 R11 15k R7 6.8k Q60 R10 75k Q35 Q34 R8 100k Q36 Q49 R16 6k Q22 Q63 Q62 Q61 Q32 Q64 Q33 C3 10pF Q45 Q37 Q46 Q47 Q48 R30 2k R31 10Ω R32 2k Q17 Q18 Q21 R17 100Ω Q41 125k Q27 Q26 Q23 C1 10pF Q28 Q56 R22 30k R23 30k R24 390k Q39 Q51 R8 40k R19 40k C6 100pF R33 138.3k 47k Q58 11 FEEDBACK VIN R4 42k SCHE ATIC DIAGRA W LT1020 Q1 Q13 OUTPUT 2 13 DROPOUT DETECTOR Q2 Q15 Q16 Q20 PNP OUTPUT 5 NPN OUTPUT 6 Q10 Q6 Q5 Q9 Q11 Q8 Q7 Q12 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 100pF Q65 R5 3k 15k 28k R6 3k R38 20k R14 15k R15 80k R18 15k 60k 60k R26 15k R27 15k R28 2k R29 5Ω 100pF 7 +INPUT –NPUT 8 12 SHUTDOWN 10 CURRENT LIMIT R1 25Ω R36 60k R2 50k R37 110.8k R3 50k 9 GND 1020 SS W 15 LT1020 PACKAGE DESCRIPTIO 0.290 – 0.320 (7.366 – 8.128) 0.008 – 0.018 (0.203 – 0.457) 0.385 ± 0.025 (9.779 ± 0.635) 0° – 15° 0.025 (0.635) RAD TYP 0.220 – 0.310 (5.588 – 7.874) 0.045 – 0.068 (1.143 – 1.727) 0.014 – 0.026 (0.360 – 0.660) NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP OR TIN PLATE LEADS. 0.300 – 0.325 (7.620 – 8.255) 0.130 ± 0.005 (3.302 ± 0.127) 0.015 (0.380) MIN 0.009 – 0.015 (0.229 – 0.381) +0.025 0.325 –0.015 +0.635 8.255 –0.381 ( ) 0.125 (3.175) MIN 0.100 ± 0.010 (2.540 ± 0.254) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0° – 8° TYP 0.016 – 0.050 0.406 – 1.270 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977 U Dimensions in inches (millimeters) unless otherwise noted. J Package 14-Lead Ceramic DIP 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.005 (0.127) MIN 0.785 (19.939) MAX 14 13 12 11 10 9 8 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) MIN 1 2 3 4 5 6 7 N Package 14-Lead Plastic DIP 0.045 – 0.065 (1.143 – 1.651) 0.770 (19.558) MAX 14 0.065 (1.651) TYP 0.075 ± 0.015 (1.905 ± 0.381) 0.018 ± 0.003 (0.457 ± 0.076) 1 2 3 4 5 6 7 13 12 11 10 9 8 0.260 ± 0.010 (6.604 ± 0.254) S Package 16-Lead Plastic SOIC 0.386 – 0.394* (9.804 – 10.008) 16 15 14 13 12 11 10 9 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157* (3.810 – 3.988) 1 0.053 – 0.069 (1.346 – 1.752) 2 3 4 5 6 7 8 0.004 – 0.010 (0.101 – 0.254) 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm). LT/GP 1193 5K REV B • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1993