LM7905C

LM7905C NSC | Alldatasheet

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Y Thermal, short circuit and safe area protection Y High ripple rejection Y 1.5A output current Y 4% tolerance on preset output voltage Connection Diagrams TL/H/7340–14 Front View Order Number LM7905CT, LM7912CT or LM7915CT See NS Package Number TO3B Typical Applications Fixed Regulator TL/H/7340–3 *Required if regulator is separated from filter capacitor by more than 3 ×. For value given, capacitor must be solid tantalum. 25 mF aluminum electrolytic may be substituted. ²Required for stability. For value given, capacitor must be solid tantalum. 25 mF aluminum electrolytic may be substi- tuted. Values given may be increased without limit. For output capacitance in excess of 100 mF, a high current diode from input to output (1N4001, etc.) will protect the regulator from momentary input shorts. C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Input Voltage o eb 5V) b25V (Vo eb 12V and b15V) b35V Input-Output Differential (Vo eb 5V) 25V (Vo eb 12V and b15V) 30V Power Dissipation (Note 2) Internally Limited Operating Junction Temperature Range 0 §Ct o a125§C Storage Temperature Range b65§Ct o a150§C Lead Temperature (Soldering, 10 sec.) 230 §C Electrical Characteristics Conditions unless otherwise noted: I OUT e 500 mA, C IN e 2.2 mF, C OUT e 1 mF, 0§C s TJ s a125§C, Power Dissipation s 1.5W. Part Number LM7905C Units Output Voltage b5V Input Voltage (unless otherwise specified) b10V Symbol Parameter Conditions Min Typ Max VO Output Voltage T J e 25§C b4.8 b5.0 b5.2 V 5m A s IOUT s 1A, b4.75 b5.25 V P s 15W ( b20 s VIN s b7) V DVO Line Regulation T J e 25§C, (Note 3) 8 50 mV (b25 s VIN s b7) V 21 5 m V (b12 s VIN s b8) V DVO Load Regulation T J e 25§C, (Note 3) 5m A s IOUT s 1.5A 15 100 mV 250 mA s IOUT s 750 mA 5 50 mV IQ Quiescent Current T J e 25§C1 2 m A DIQ Quiescent Current With Line 0.5 mA Change ( b25 s VIN s b7) V With Load, 5 mA s IOUT s 1A 0.5 mA Vn Output Noise Voltage T A e 25§C, 10 Hz s f s 100 Hz 125 mV Ripple Rejection f e 120 Hz 54 66 dB (b18 s VIN s b8) V Dropout Voltage T J e 25§C, I OUT e 1A 1.1 V IOMAX Peak Output Current T J e 25§C 2.2 A Average Temperature I OUT e 5 mA, 0.4 mV/ §C Coefficient of 0 C s TJ s 100§C Output Voltage Typical Applications (Continued) Variable Output TL/H/7340–2 *Improves transient response and ripple rejection. Do not increase beyond 50 mF. VOUT e VSET # R1 a R2 R2 J Select R2 as follows: LM7905CT 300 X LM7912CT 750 X LM7915CT 1k

Electrical Characteristics (Continued) Conditions unless otherwise noted: I OUT e 500 mA, C IN e 2.2 mF, COUT e 1 mF, 0 §C s TJ s a125§C, Power Dissipation e 1.5W. Part Number LM7912C LM7915C Units Output Voltage b12V b15V Input Voltage (unless otherwise specified) b19V b23V Symbol Parameter Conditions Min Typ Max Min Typ Max 5m A s IOUT s 1A, b11.4 b12.6 b14.25 b15.75 V P s 15W ( b27 s VIN s b14.5) ( b30 s VIN s b17.5) V DVO Line Regulation T J e 25§C, (Note 3) 5 80 5 100 mV (b30 s VIN s b14.5) ( b30 s VINs b17.5) V 3 30 3 50 mV (b22 s VIN s b16) ( b26 s VIN sb20) V DVO Load Regulation T J e 25§C, (Note 3) 5m A s IOUT s 1.5A 15 200 15 200 mV 250 mA s IOUT s 750 mA 5 75 5 75 mV IQ Quiescent Current T J e 25§C 1.5 3 1.5 3 mA DIQ Quiescent Current With Line 0.5 0.5 mA Change ( b30 s VIN s b14.5) ( b30 sVIN s b17.5) V With Load, 5 mA s IOUT s 1A 0.5 0.5 mA Vn Output Noise Voltage T A e 25§C, 10 Hz s f s 100 Hz 300 375 mV Ripple Rejection f e 120 Hz 54 70 54 70 dB (b25 s VIN s b15) ( b30 s VINs b17.5) V Dropout Voltage T J e 25§C, I OUT e 1A 1.1 1.1 V IOMAX Peak Output Current T J e 25§C 2.2 2.2 A Average Temperature I OUT e 5 mA, b0.8 b1.0 mV/ §C Coefficient of 0 C s TJ s 100§C Output Voltage Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee Specific Performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: Refer to Typical Performance Characteristics and Design Considerations for details. Note 3: Regulation is measured at a constant junction temperature by pulse testing with a low duty cycle. Changes in output voltage due to heating effects must be taken into account. Typical Applications (Continued) Dual Trimmed Supply TL/H/7340–4

The LM79XX fixed voltage regulator series has thermal overload protection from excessive power dissipation, inter- nal short circuit protection which limits the circuit’s maxi- mum current, and output transistor safe-area compensation for reducing the output current as the voltage across the pass transistor is increased. Although the internal power dissipation is limited, the junc- tion temperature must be kept below the maximum speci- fied temperature (125 §C) in order to meet data sheet specifi- cations. To calculate the maximum junction temperature or heat sink required, the following thermal resistance values should be used: Typ Max Typ Max Package iJC iJC iJA iJA §C/W §C/W §C/W §C/W TO-220 3.0 5.0 60 40 PD MAX e TJ Max b TA iJC a iCA or TJ Max TA iJA iCA e iCS a iSA (without heat sink) Solving for T J: TJ e TA a PD (iJC a iCA)o r e TA a PDiJA (without heat sink) Where: TJ e Junction Temperature TA e Ambient Temperature PD e Power Dissipation iJA e Junction-to-Ambient Thermal Resistance iJC e Junction-to-Case Thermal Resistance iCA e Case-to-Ambient Thermal Resistance iCS e Case-to-Heat Sink Thermal Resistance iSA e Heat Sink-to-Ambient Thermal Resistance Typical Applications (Continued) Bypass capacitors are necessary for stable operation of the LM79XX series of regulators over the input voltage and out- put current ranges. Output bypass capacitors will improve the transient response by the regulator. The bypass capacitors, (2.2 mF on the input, 1.0 mFo nt h e output) should be ceramic or solid tantalum which have good high frequency characteristics. If aluminum electrolyt- ics are used, their values should be 10 mF or larger. The bypass capacitors should be mounted with the shortest leads, and if possible, directly across the regulator termi- nals. High Stability 1 Amp Regulator TL/H/7340–5 Load and line regulation k 0.01% temperature stability s 0.2% ²Determine Zener current ²² Solid tantalum *Select resistors to set output voltage. 2 ppm/ §C tracking suggested

Typical Applications (Continued) Current Source *IOUT e 1m A a 5V R1 TL/H/7340–7 Light Controller Using Silicon Photo Cell TL/H/7340–8 *Lamp brightness increase until i I e iQ (& 1 mA) a 5V/R1. ²Necessary only if raw supply filter capacitor is more than 2 × from LM7905CT

Typical Applications (Continued) High-Sensitivity Light Controller TL/H/7340–9 *Lamp brightness increases until i i e 5V/R1 (I i can be set as low as 1 mA) ²Necessary only if raw supply filter capacitor is more than 2 × from LM7905 g15V, 1 Amp Tracking Regulators TL/H/7340–1 (b15) ( a15) Load Regulation at DIL e 1A 40 mV 2 mV Output Ripple, C IN e 3000 mF, I L e 1A 100 mVrms 100 mVrms Temperature Stability 50 mV 50 mV Output Noise 10 Hz s f s 10 kHz 150 mVrms 150 mVrms *Resistor tolerance of R4 and R5 determine matching of ( a) and ( b) outputs. **Necessary only if raw supply filter capacitors are more than 3 × from regu- lators.

TL/H/7340–12

Schematic Diagrams (Continued) b12V and b15V TL/H/7340–13

LM79XX Series 3-Terminal Negative Regulators Physical Dimensions inches (millimeters) TO-220 Outline Package (T) Order Number LM7905CT, LM7912CT or LM7915CT LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or 2. A critical component is any component of a life systems which, (a) are intended for surgical implant support device or system whose failure to perform can into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life failure to perform, when properly used in accordance support device or system, or to affect its safety or with instructions for use provided in the labeling, can effectiveness. be reasonably expected to result in a significant injury to the user. National Semiconductor National Semiconductor National Semiconductor National Semiconductor Corporation Europe Hong Kong Ltd. Japan Ltd.

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