A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 D D D D D D 3-Terminal Regulators Output Current up to 100 mA No External Components Internal Thermal-Overload Protection Internal Short-Circuit Current Limiting Direct Replacements for Fairchild A78L00 Series D PACKAGE (TOP VIEW) OUTPUT COMMON COMMON NC 1 8 2 7 3 6 4 5 INPUT COMMON COMMON NC NC - No internal connection description LP PACKAGE (TOP VIEW) This series of fixed-voltage integrated-circuit voltage regulators is designed for a wide range of applications. These applications include on-card regulation for elimination of noise and distribution problems associated with single-point regulation. In addition, they can be used with power-pass elements to make high-current voltage regulators. One of these regulators can deliver up to 100 mA of output current. The internal limiting and thermal-shutdown features of these regulators make them essentially immune to overload. When used as a replacement for a zener diode-resistor combination, an effective improvement in output impedance can be obtained, together with lower bias current. INPUT COMMON OUTPUT TO-226AA PK PACKAGE (TOP VIEW) INPUT COMMON The A78L00C series is characterized for operation over the virtual junction temperature range of 0C to 125C. OUTPUT AVAILABLE OPTIONS PACKAGED DEVICES TJ 0C to 125C VO(NOM) (V) 2.6 5 6.2 8 9 10 12 15 SMALL OUTLINE (D) PLASTIC CYLINDRICAL (LP) SOT-89 (PK) CHIP FORM (Y) OUTPUT VOLTAGE TOLERANCE 5% 10% 5% 10% 5% 10% A78L02ACD A78L05ACD A78L06ACD A78L08ACD A78L09ACD A78L10ACD A78L12ACD A78L15ACD - A78L05CD A78L06CD A78L08CD A78L09CD - A78L12CD A78L15CD A78L02ACLP A78L05ACLP A78L06ACLP A78L08ACLP A78L09ACLP A78L10ACLP A78L12ACLP A78L15ACLP A78L02CLP A78L05CLP A78L06CLP A78L08CLP A78L09CLP A78L10CLP A78L12CLP A78L15CLP A78L02ACPK A78L05ACPK A78L06ACPK A78L08ACPK A78L09ACPK A78L10ACPK A78L12ACPK A78L15ACPK A78L02CPK A78L05CPK A78L06CPK A78L08CPK A78L09CPK A78L10CPK A78L12CPK A78L15CPK A78L02Y A78L05Y A78L06Y A78L08Y A78L09Y A78L10Y A78L12Y A78L15Y D and LP packages are available taped and reeled. Add the suffix R to the device type (e.g., A78L05ACDR). The PK package is only available taped and reeled (e.g., A78L02ACPKR). Chip forms are tested at TA = 25C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright 1999, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 1 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 schematic INPUT 20 k OUTPUT 1 k to 14 k 1.4 k COMMON NOTE: Resistor values shown are nominal. 2 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 absolute maximum ratings over operating temperature range (unless otherwise noted) A78Lxx Input voltage voltage, VI Package thermal impedance, JA (see Notes 1 and 2) A78L02AC, A78L05C-A78L09C, A78L10AC 30 A78L12C, A78L12AC, A78L15C, A78L15AC 35 D package 97 LP package 156 PK package 52 V C 0 to 150 C 260 C -65 to 150 C Virtual junction temperature range, TJ Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds Storage temperature range, Tstg UNIT Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. Maximum power dissipation is a function of TJ(max), JA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) - TA)/JA. Operating at the absolute maximum TJ of 150C can impact reliability. Due to variations in individual device electrical characteristics and thermal resistance, the built-in thermal-overload protection may be activated at power levels slightly above or below the rated dissipation. 2. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace length of zero. recommended operating conditions A78L02AC Input voltage, voltage VI MIN MAX 4.75 20 A78L05C, A78L05AC 7 20 A78L06C, A78L06AC 8.5 20 A78L08C, A78L08AC 10.5 23 A78L09C, A78L09AC 11.5 24 A78L10AC 12.5 25 A78L12C, A78L12AC 14.5 27 A78L15C, A78L15AC 17.5 30 Output current, IO Operating virtual junction temperature, TJ 0 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 UNIT V 100 mA 125 C 3 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 9 V, IO = 40 mA (unless otherwise noted) PARAMETER VI = 4.75 4 75 V to 20 V, V Output voltage Input voltage regulation Ripple rejection IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 4.75 V to 20 V VI = 5 V to 20 V VI = 6 V to 20 V, A78L02C TJ TEST CONDITIONS MIN TYP 2.6 25C 2.5 0C to 125C 2.45 2.75 0C to 125C 2.45 2.75 25C f = 120 Hz MAX 25C 43 UNIT 2.7 20 100 16 75 51 V mV dB Output voltage regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 30 V 25C 1.7 V 25C 3.6 Dropout voltage Bias current Bias current change 12 50 6 25 125C VI = 5 V to 20 V IO = 1 mA to 40 mA 6 5.5 2.5 0C to 125C 0.1 mV mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 10 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage Input voltage regulation TJ TEST CONDITIONS VI = 7 V to 20 V, V IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 7 V to 20 V A78L05C TYP MAX MIN TYP MAX 25C 4.6 5 5.4 4.8 5 5.2 0C to 125C 4.5 5.5 4.75 5.25 0C to 125C 4.5 5.5 4.75 5.25 25C 32 200 32 150 26 150 26 100 Ripple rejection VI = 8 V to 20 V VI = 8 V to 18 V, Output voltage regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 42 25C 1.7 25C 3.8 f = 120 Hz 25C Dropout voltage Bias current Bias current change 40 125C VI = 8 V to 20 V IO = 1 mA to 40 mA A78L05AC MIN 0C to 125C 49 41 49 60 15 60 8 30 8 30 mV mV V 42 1.7 3.8 V dB 15 6 UNIT V 6 5.5 5.5 1.5 1.5 0.2 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 12 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage Input voltage regulation TEST CONDITIONS VI = 8.5 8 5 V to 20 V, V IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 8.5 V to 20 V TJ A78L06C TYP MAX MIN TYP MAX 6.2 6.2 6.45 25C 5.7 6.7 5.95 0C to 125C 5.6 6.8 5.9 6.5 0C to 125C 5.6 6.8 5.9 6.5 25C 35 200 35 175 29 150 29 125 Ripple rejection VI = 9 V to 20 V VI = 10 V to 20 V, Output voltage regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 46 25C 1.7 25C 3.9 f = 120 Hz Dropout voltage Bias current Bias current change 25C 39 48 40 48 80 16 80 9 40 9 40 0C to 125C 1.7 3.9 V mV mV V 46 6 UNIT dB 16 125C VI = 9 V to 20 V IO = 1 mA to 40 mA A78L06AC MIN V 6 5.5 5.5 1.5 1.5 0.2 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 14 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage Input voltage g regulation TEST CONDITIONS 5 V to 23 V VI = 10 10.5 V, IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 10.5 V to 23 V TJ A78L08C A78L08AC MIN TYP MAX MIN TYP MAX 25C 7.36 8 8.64 7.7 8 8.3 0C to 125C 7.2 8.8 7.6 8.4 0C to 125C 7.2 8.8 7.6 8.4 25C 42 200 42 175 36 150 36 125 UNIT V mV Ripple rejection VI = 11 V to 23 V VI = 13 V to 23 V, Output voltage g regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 54 54 V 25C 1.7 1.7 V 25C 4 Dropout voltage Bias current Bias current change f = 120 Hz 25C 36 125C VI = 5 V to 20 V IO = 1 mA to 40 mA 0C to 125C 46 37 46 dB 18 80 18 80 10 40 10 40 6 4 6 5.5 5.5 1.5 1.5 0.2 0.1 mV mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 5 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 16 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage Input voltage regulation TJ TEST CONDITIONS VI = 12 V to 24 V V, IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 12 V to 24 V A78L09C TYP MAX 9 9 MAX 8.3 9.7 8.6 8.1 9.9 8.55 9.45 0C to 125C 8.1 9.9 8.55 9.45 25C 225 45 175 40 175 40 125 Output voltage regulation 25C Output noise voltage f = 10 Hz to 100 kHz 25C 58 25C 1.7 25C 4.1 f = 120 Hz 25C Dropout voltage 36 45 38 45 90 19 90 11 40 11 40 125C 0C to 125C mV mV V 58 1.7 4.1 V dB 19 6 UNIT 9.4 45 IO = 1 mA to 100 mA IO = 1 mA to 40 mA VI = 13 V to 24 V IO = 1 mA to 40 mA TYP 25C Ripple rejection Bias current change MIN 0C to 125C VI = 13 V to 24 V VI = 15 V to 25 V, Bias current A78L09AC MIN V 6 5.5 5.5 1.5 1.5 0.2 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 14 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage Input voltage regulation Ripple rejection TEST CONDITIONS VI = 13 V to 25 V V, IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 13 V to 25 V VI = 14 V to 25 V VI = 15 V to 25 V, A78L10AC TJ MIN TYP MAX 25C 9.6 10 10.4 0C to 125C 9.5 10.5 0C to 125C 9.5 10.5 25C f = 120 Hz 25C 37 51 175 42 125 44 Output voltage regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 62 25C 1.7 25C 4.2 Dropout voltage Bias current Bias current change 125C VI = 14 V to 25 V IO = 1 mA to 40 mA 0C to 125C UNIT V mV dB 20 90 11 40 mV V V 6 5.5 1.5 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. 6 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 19 V, IO = 40 mA (unless otherwise noted) PARAMETER TEST CONDITIONS VI = 14 V to 27 V V, Output voltage Input voltage regulation IO = 1 mA to 40 mA IO = 1 mA to 70 mA VI = 14.5 V to 27 V TJ A78L12C TYP MAX MIN TYP MAX 12 12 12.5 25C 11.1 12.9 11.5 0C to 125C 10.8 13.2 11.4 12.6 0C to 125C 10.8 13.2 11.4 12.6 25C 55 250 55 250 49 200 49 200 Ripple rejection VI = 16 V to 27 V VI = 15 V to 25 V, Output voltage regulation IO = 1 mA to 100 mA IO = 1 mA to 40 mA 25C Output noise voltage f = 10 Hz to 100 kHz 25C 70 25C 1.7 25C 4.3 f = 120 Hz Dropout voltage Bias current Bias current change 25C 36 42 37 42 100 22 100 13 50 13 50 0C to 125C V mV mV V 70 1.7 6.5 UNIT dB 22 125C VI = 16 V to 27 V IO = 1 mA to 40 mA A78L12AC MIN V 4.3 6.5 6 6 1.5 1.5 0.2 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 23 V, IO = 40 mA (unless otherwise noted) PARAMETER Output voltage TEST CONDITIONS 17 5 V to 30 V, V VI = 17.5 IO = 1 mA to 40 mA IO = 1 mA to 70 mA Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage A78L15C TYP MAX 25C 13.8 15 0C to 125C 13.5 0C to 125C 13.5 25C VI = 20 V to 30 V VI = 18.5 V to 28.5 V, IO = 1 mA to 100 mA f = 120 Hz 25C 33 25C IO = 1 mA to 40 mA f = 10 Hz to 100 kHz Bias current MIN TYP MAX 16.2 14.4 15 16.5 14.25 15.75 16.5 14.25 15.75 15.6 65 300 65 300 58 250 58 250 39 34 UNIT 39 V mV dB 25 150 25 150 15 75 15 75 mV 25C 82 82 V 25C 1.7 1.7 V 25C 4.6 125C VI = 10 V to 30 V IO = 1 mA to 40 mA A78L15AC MIN VI = 17.5 V to 30 V Dropout voltage Bias current change TJ 0C to 125C 6.5 4.6 6.5 6 6 1.5 1.5 0.2 0.1 mA mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 7 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 9 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS A78L02Y MIN Output voltage TYP MAX 2.6 Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage VI = 4.75 V to 20 V VI = 5 V to 20 V VI = 6 V to 20 V, IO = 1 mA to 100 mA V 20 mV 16 f = 120 Hz 51 dB 12 IO = 1 mA to 40 mA f = 10 Hz to 100 kHz UNIT mV 6 V 30 Dropout voltage 1.7 V Bias current 3.6 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 10 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS A78L05Y MIN Output voltage TYP MAX 5 Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage VI = 7 V to 20 V VI = 8 V to 20 V VI = 8 V to 18 V, IO = 1 mA to 100 mA V 32 mV 26 f = 120 Hz 49 dB 15 IO = 1 mA to 40 mA f = 10 Hz to 100 kHz mV 8 Dropout voltage UNIT 42 V 1.7 V Bias current 3.8 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 12 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS Output voltage Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage A78L06Y MIN TYP 6.2 VI = 8.5 V to 20 V VI = 9 V to 20 V VI = 10 V to 20 V, IO = 1 mA to 100 mA 35 29 f = 120 Hz IO = 1 mA to 40 mA f = 10 Hz to 100 kHz 48 16 9 46 MAX UNIT V mV dB mV V Dropout voltage 1.7 V Bias current 3.9 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. 8 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 14 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS A78L08Y MIN Output voltage TYP MAX 8 Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage VI = 10.5 V to 23 V VI = 11 V to 23 V VI = 13 V to 23 V, IO = 1 mA to 100 mA V 42 mV 36 f = 120 Hz 46 dB 18 IO = 1 mA to 40 mA f = 10 Hz to 100 kHz mV 10 Dropout voltage UNIT 54 V 1.7 V Bias current 4 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 16 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS A78L09Y MIN Output voltage TYP MAX 9 Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage VI = 12 V to 24 V VI = 13 V to 24 V VI = 15 V to 25 V, IO = 1 mA to 100 mA V 45 mV 40 f = 120 Hz 45 dB 19 IO = 1 mA to 40 mA f = 10 Hz to 100 kHz UNIT mV 11 V 58 Dropout voltage 1.7 V Bias current 4.1 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 14 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS Output voltage Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage A78L10Y MIN TYP 10 VI = 13 V to 25 V VI = 14 V to 25 V VI = 15 V to 25 V, IO = 1 mA to 100 mA 51 42 f = 120 Hz IO = 1 mA to 40 mA f = 10 Hz to 100 kHz Dropout voltage 44 20 11 MAX UNIT V mV dB mV 62 V 1.7 V Bias current 4.2 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 9 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 electrical characteristics at specified virtual junction temperature, VI = 19 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS A78L12Y MIN Output voltage TYP MAX 12 Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage VI = 14.5 V to 27 V VI = 16 V to 27 V VI = 15 V to 25 V, IO = 1 mA to 100 mA V 55 mV 49 f = 120 Hz 42 dB 22 IO = 1 mA to 40 mA f = 10 Hz to 100 kHz mV 13 Dropout voltage UNIT 70 V 1.7 V Bias current 4.3 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. electrical characteristics at specified virtual junction temperature, VI = 23 V, IO = 40 mA, TJ = 25C (unless otherwise noted) PARAMETER TEST CONDITIONS Output voltage Input voltage regulation Ripple rejection Output voltage regulation Output noise voltage A78L15Y MIN TYP 15 VI = 17.5 V to 30 V VI = 20 V to 30 V VI = 18.5 V to 28.5 V, IO = 1 mA to 100 mA 65 58 f = 120 Hz IO = 1 mA to 40 mA f = 10 Hz to 100 kHz 39 25 15 82 MAX UNIT V mV dB mV V Dropout voltage 1.7 V Bias current 4.6 mA Pulse-testing techniques maintain TJ as close to TA as possible. Thermal effects must be taken into account separately. All characteristics are measured with a 0.33-F capacitor across the input and a 0.1-F capacitor across the output. 10 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 APPLICATION INFORMATION A78Lxx VI VO 0.33 F 0.1 F Figure 1. Fixed-Output Regulator IN + A78Lxx VI OUT G IL COM -VO - Figure 2. Positive Regulator in Negative Configuration (VI Must Float) Input A78Lxx Output R1 IO 0.33 F 0.1 F R2 Figure 3. Adjustable-Output Regulator A78Lxx Input 0.33 F R1 VO(Reg) Output IO IO = (VO/R1) + IO Bias Current Figure 4. Current Regulator POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 11 A78L00 SERIES POSITIVE-VOLTAGE REGULATORS SLVS010I - JANUARY 1976 - REVISED JULY 1999 APPLICATION INFORMATION 1N4001 A78L15 20-V Input VO = 15 V 0.33 F 0.1 F 1N4001 0.1 F 0.33 F 1N4001 A79L15 -20-V Input VO = -15 V 1N4001 Figure 5. Regulated Dual Supply operation with a load common to a voltage of opposite polarity In many cases, a regulator powers a load that is not connected to ground but, instead, is connected to a voltage source of opposite polarity (e.g., operational amplifiers, level-shifting circuits, etc.). In these cases, a clamp diode should be connected to the regulator output as shown in Figure 6. This protects the regulator from output polarity reversals during startup and short-circuit operation. A78Lxx VI VO 1N4001 or Equivalent - VO Figure 6. Output Polarity-Reversal-Protection Circuit reverse-bias protection Occasionally, the input voltage to the regulator can collapse faster than the output voltage. This can occur, for example, when the input supply is crowbarred during an output overvoltage condition. If the output voltage is greater than approximately 7 V, the emitter-base junction of the series-pass element (internal or external) could break down and be damaged. To prevent this, a diode shunt can be employed as shown in Figure 7. VI A78Lxx VO Figure 7. Reverse-Bias-Protection Circuit 12 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE ("CRITICAL APPLICATIONS"). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI's publication of information regarding any third party's products or services does not constitute TI's approval, warranty or endorsement thereof. Copyright 1999, Texas Instruments Incorporated