LM78L00 Series 3-Terminal Positive Voltage Regulators General Description Features The LM78L00 series of 3-terminal positive voltage regulators employ internal current-limiting and thermal shutdown, making them essentially indestructible. If adequate heat sinking is provided, they can deliver up to 100 mA output current. They are intended as fixed voltage regulators in a wide range of applications including local (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. The LM78L00, used as a Zener diode/resistor combination replacement, offers an effective output impedance improvement of typically two orders of magnitude, along with lower quiescent current and lower noise. Y Y Y Y Y Y Y Output current up to 100 mA No external components Internal thermal overload protection Internal short circuit current-limiting Available in JEDEC TO-92 Output Voltages of 5.0V, 6.2V, 8.2V, 9.0V, 12V, 15V Output voltage tolerances of g 5% over the temperature range Connection Diagram TL/H/10051 - 1 Top View Order Number LM78L05ACZ, LM78L09ACZ, LM78L12ACZ, LM78L15ACZ, LM78L62ACZ or LM78L82ACZ See NS Package Number Z03A C1995 National Semiconductor Corporation TL/H/10051 RRD-B30M115/Printed in U. S. A. LM78L00 Series 3-Terminal Positive Voltage Regulators June 1989 Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Lead Temperature TO-92 Package/SO-8 (Soldering, 10 sec.) Storage Temperature Range Power Dissipation Input Voltage 5.0V to 15V ESD Susceptibility b 65 C to a 150 C Operation Junction Temperature Range Commercial (LM78L00AC) 0 C to a 125 C 265 C Internally Limited 35V to be determined LM78L05AC Electrical Characteristics 0 C s TA s a 125 C, VI e 10V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol VO VR LINE VR LOAD VO Parameter Conditions Output Voltage TJ e 25 C Line Regulation TJ e 25 C Load Regulation TJ e 25 C Output Voltage (Note 2) IQ Quiescent Current DIQ Quiescent Current Change Min Typ Max Units 4.8 5.0 5.2 V 7.0V s VI s 20V 55 150 8.0V s VI s 20V 45 100 1.0 mA s IO s 100V 11 60 1.0 mA s IO s 40 mA 5.0 30 7.0V s VI s 20V 1.0 mA s IO s 40 mA 4.75 5.25 7.0V s VI s VMax 1.0 mA s IO s 70 mA 4.75 5.25 2.0 5.5 With Line 8.0V s VI s 20V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 NO Noise TA e 25 C, 10 Hz s f s 100 kHz DVI/DVO Ripple Rejection f e 120 Hz, 8.0V s VI s 18V, TJ e 25 C VDO Dropout Voltage Ipk/IOS DVO/DT mV mV V mA mA 40 mV 49 dB TJ e 25 C 1.7 V Peak Output/Output Short Circuit Current TJ e 25 C 140 mA Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 0.65 mV/ C 41 Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data above represent pulse test conditions with junction temperatures as indicated at the initiation of tests. Note 2: Power Dissipation s 0.75W. 2 LM78L62AC Electrical Characteristics 0 C s TA s a 125 C, VI e 12V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol Parameter Conditions VO Output Voltage TJ e 25 C VR LINE Line Regulation TJ e 25 C VR LOAD VO Load Regulation Output Voltage (Note 2) IQ Quiescent Current DIQ Quiescent Current Change NO TJ e 25 C Min Typ Max Units 5.95 6.2 6.45 V 8.5V s VI s 20V 65 175 9.0V s VI s 20V 55 125 1.0 mA s IO s 100 mA 13 80 1.0 mA s IO s 40 mA 6.0 40 8.5V s VI s 20V 1.0 mA s IO s 40 mA 5.90 6.5 8.5V s VI s VMax 1.0 mA s IO s 70 mA 5.90 6.5 2.0 5.5 With Line 8.0V s VI s 20V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 Noise TA e 25 C, 10 Hz s f s 100 kHz 40 mV mV V mA mA 50 mV DVI/DVO Ripple Rejection f e 120 Hz, 10V s VI s 20V, TJ e 25 C 46 dB VDO Dropout Voltage TJ e 25 C 1.7 V Ipk/IOS Peak Output/Output Short Circuit Current TJ e 25 C 140 mA DVO/DT Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 0.75 mV/ C LM78L82AC Electrical Characteristics 0 C s TA s a 125 C, VI e 14V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol VO VR LINE VR LOAD VO Parameter Conditions Output Voltage TJ e 25 C Line Regulation TJ e 25 C Load Regulation TJ e 25 C Output Voltage (Note 2) IQ Quiescent Current DIQ Quiescent Current Change Min Typ Max Units 7.87 8.2 8.53 V 11V s VI s 23V 80 175 12V s VI s 23V 70 125 1.0 mA s IO s 100 mA 15 80 1.0 mA s IO s 40 mA 8.0 40 11V s VI s 23V 1.0 mA s IO s 40 mA 7.8 8.5 11V s VI s VMax 1.0 mA s IO s 70 mA 7.8 8.6 2.1 5.5 With Line 12V s VI s 23V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 NO Noise TA e 25 C, 10 Hz s f s 100 kHz DVI/DVO Ripple Rejection f e 120 Hz, 12V s VI s 22V, TJ e 25 C VDO Dropout Voltage Ipk/IOS DVO/DT mV mA V mA mA 60 mV 45 dB TJ e 25 C 1.7 V Peak Output/Output Short Circuit Current TJ e 25 C 140 mA Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 0.8 mV/ C 39 Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data above represent pulse test conditions with junction temperatures as indicated at the initiation of tests. Note 2: Power Dissipation s 0.75W. 3 LM78L09AC Electrical Characteristics 0 C s TA s a 125 C, VI e 15V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol Parameter Conditions VO Output Voltage TJ e 25 C VR LINE Line Regulation TJ e 25 C VR LOAD VO IQ DIQ Load Regulation TJ e 25 C Output Voltage (Note 2) Min Typ Max Units 8.64 9.0 9.36 V 11.5V s VI s 24V 90 200 13V s VI s 24V 100 150 1.0 mA s IO s 100 mA 20 90 1.0 mA s IO s 40 mA 10 45 11.5V s VI s 24V 1.0 mA s IO s 40 mA 8.55 9.45 11.5V s VI s VMax 1.0 mA s IO s 70 mA 8.55 9.45 Quiescent Current Quiescent Current Change 2.1 5.5 With Line 11.5V s VI s 24V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 NO Noise TA e 25 C, 10 Hz s f s 100 kHz DVI/DVO Ripple Rejection f e 120 Hz, 15V s VI s 25V, TJ e 25 C VDO Ipk/IOS DVO/DT mV mV V mA mA 70 mV 44 dB Dropout Voltage TJ e 25 C 1.7 V Peak Output/Output Short Circuit Current TJ e 25 C 140 mA Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 0.9 mV/ C 38 LM78L12AC Electrical Characteristics 0 C s TA s a 125 C, VI e 19V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol Parameter Conditions VO Output Voltage TJ e 25 C VR LINE Line Regulation TJ e 25 C VR LOAD VO Load Regulation TJ e 25 C Output Voltage (Note 2) IQ Quiescent Current DIQ Quiescent Current Change Min Typ Max Units 11.5 12 12.5 V 14.5V s VI s 27V 120 250 16V s VI s 27V 100 200 1.0 mA s IO s 100 mA 20 100 1.0 mA s IO s 40 mA 10 50 14.5V s VI s 27V 1.0 mA s IO s 40 mA 11.4 12.6 14.5V s VI s VMax 1.0 mA s IO s 70 mA 11.4 12.6 2.1 5.5 With Line 16V s VI s 27V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 NO Noise TA e 25 C, 10 Hz s f s 100 kHz DVI/DVO Ripple Rejection f e 120 Hz, 15V s VI s 25V, TJ e 25 C VDO Dropout Voltage Ipk/IOS DVO/DT mV mV V mA mA 80 mV 42 dB TJ e 25 C 1.7 V Peak Output/Output Short Circuit Current TJ e 25 C 140 mA Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 1.0 mV/ C 37 Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data above represent pulse test conditions with junction temperatures as indicated at the initiation of tests. Note 2: Power Dissipation s 0.75W. 4 LM78L15AC Electrical Characteristics 0 C s TA s a 125 C, VI e 23V, IO e 40 mA, CI e 0.33 mF, CO e 0.1 mF, unless otherwise specified (Note 1) Symbol Parameter Conditions VO Output Voltage TJ e 25 C VR LINE Line Regulation TJ e 25 C VR LOAD VO IQ DIQ Load Regulation TJ e 25 C Output Voltage (Note 2) Min Typ Max Units 14.4 15 15.6 V 17.5V s VI s 30V 130 300 20V s VI s 30V 110 250 1.0 mA s IO s 100 mA 25 150 1.0 mA s IO s 40 mA 12 75 17.5V s VI s 30V 1.0 mA s IO s 40 mA 14.25 15.75 17.5V s VI s VMax 1.0 mA s IO s 70 mA 14.25 15.75 Quiescent Current Quiescent Current Change 2.2 5.5 With Line 20V s VI s 30V 1.5 With Load 1.0 mA s IO s 40 mA 0.1 NO Noise TA e 25 C, 10 Hz s f s 100 kHz DVI/DVO Ripple Rejection f e 120 Hz, 18.5V s VI s 28.5V, TJ e 25 C VDO Ipk/IOS DVO/DT mV mV V mA mA 90 mV 39 dB Dropout Voltage TJ e 25 C 1.7 V Peak Output/Output Short Circuit Current TJ e 25 C 140 mA Average Temperature Coefficient of Output Voltage IO e 5.0 mA b 1.3 mV/ C 34 Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data above represent pulse test conditions with junction temperatures as indicated at the initiation of tests. Note 2: Power Dissipation s 0.75W. Equivalent Circuit TL/H/10051 - 2 5 Typical Performance Characteristics Worst Case Power Dissipation vs Ambient Temperature (TO-92) Dropout Voltage vs Junction Temperature Dropout Characteristics Quiescent Current vs Input Voltage Quiescent Current vs Temperature Ripple Rejection vs Frequency Line Transient Response Load Transient Response TL/H/10051 - 3 Note: Other LM78L00 Series devices have similar curves. 6 Design Considerations The LM78L series regulators have thermal overload protection from excessive power, internal short-circuit protection which limits each circuit's maximum current, and output transistor safe-area protection for reducing the output current as the voltage across each pass transistor is increased. Although the internal power dissipation is limited, the junction temperature must be kept below the maximum specified temperature (125 C) in order to meet data sheet specifications. To calculate the maximum junction temperature or heat sink required, the following thermal resistance values should be used: TL/H/10051 - 4 Package Typ iJC Max iJC TO-92 Typ iJA Max iJA 160 160 FIGURE 1. TO-92 Thermal Equivalent Circuit Methods of Heat Sinking With two external thermal resistances in each leg of a parallel network available to the circuit designer as variables, he can choose the method of heat sinking most applicable to his particular situation. To demonstrate, consider the effect of placing a small 72 C/W flag type heat sink, such as the Staver F1-7D-2, on the LM78L00 molded case. The heat sink effectively replaces the iCA (Figure 2) and the new thermal resistance, iE JA, equals 145 C/W (assuming, 0.125 inch lead length). The net change of 15 C/W increases the allowable power dissipation to 0.86W with a minimal inserted cost. A still further decrease in iJA could be achieved by using a heat sink rated at 46 C/W, such as the Staver FS-7A. Also, if the case sinking does not provide an adequate reduction in total iJA, the other external thermal resistance, iLA, may be reduced by shortening the lead length from package base to mounting medium. However, one point must be kept in mind. The lead thermal path includes a thermal resistance, iSA, from the leads at the mounting point to ambient, that is, the mounting medium. iLA is then equal to iLS a iSA. The new model is shown in Figure 2 . In the case of a socket, iSA could be as high as 270 C/W, thus causing a net increase in iJA and a consequent decrease in the maximum dissipation capability. Shortening the lead length may return the net iJA to the original value, but lead sinking would not be accomplished. In those cases where the regulator is inserted into a copper clad printed circuit board, it is advantageous to have a maximum area of copper at the entry points of the leads. While it would be desirable to rigorously define the effect of PC board copper, the real world variables are too great to allow anything more than a few general observations. Thermal Considerations The TO-92 molded package is capable of unusually high power dissipation due to the lead frame design. However, its thermal capabilities are generally overlooked because of a lack of understanding of the thermal paths from the semiconductor junction to ambient temperature. While thermal resistance is normally specified for the device mounted 1 cm above an infinite heat sink, very little has been mentioned of the options available to improve on the conservatively rated thermal capability. An explanation of the thermal paths of the TO-92 will allow the designer to determine the thermal stress he is applying in any given application. The TO-92 Package The TO-92 package thermal paths are complex. In addition to the path through the molding compound to ambient temperature, there is another path through the leads, in parallel with the case path, to ambient temperature, as shown in Figure 1 . The total thermal resistance in this model is then: iJA e (iJC a iCA) (iJL a iLA) iJC a iCA a iJL a iLA (1) Where: iJC e thermal resistance of the case between the regulator die and a point on the case directly above the die location. iCA e thermal resistance between the case and air at ambient temperature. iJL e thermal resistance from regulator die through the input lead to a point (/16 inch below the regulator case. iLA e total thermal resistance of the input/output ground leads to ambient temperature. iJA e junction to ambient thermal resistance. 7 Regulator power dissipation at maximum input voltage and maximum load current is now Methods of Heat Sinking (Continued) The best analogy for PC board copper is to compare it with parallel resistors. Beyond some point, additional resistors are not significantly effective; beyond some point, additional copper area is not effective. PD Max e (V1 b VO) IL Max a V1 IQ (3) where: V1 e VI Max b (IL Max a IQ) R1 The presence of R1 will affect load regulation according to the equation: Load regulation (at constant VI) (4) e load regulation (at constant V1) a line regulation (mV per V) c (RI) c (DIL). As an example, consider a 15V regulator with a supply voltage of 30 g 5.0V, required to supply a maximum load current of 30 mA. IQ is 4.3 mA, and minimum load current is to be 10 mA. R1 e TL/H/10051 - 5 FIGURE 2. TO-92 Thermal Equivalent Circuit (Lead at other than Ambient Temperature) 25 b 15 b 2 8 j 240X e 30 a 4.3 34.3 (5) V1 e 35 b (30 a 4.3) 0.24 e 35 b 8.2 e 26.8V PD Max e (26.8 b15) 30 a 26.8 (4.3) e 354 a 115 e 470 mW, which permit operation up to 70 C in most applications. High Dissipation Applications Line regulation of this circuit is typically 110 mV for an input range of 25V - 35V at a constant load current; i.e. 11 mV/V. Load regulation e constant V1 load regulation (6) (typically 10 mV, 10 mA - 30 mA IL) a (11 mV/V) c 0.24 c 20 mA (typically 53 mV) e 63 mV for a load current change of 20 mA at a constant VI of 30V. TL/H/10051 - 6 Typical Applications TL/H/10051 - 7 Where it is necessary to operate a LM78L00 regulator with a large input/output differential voltage, the addition of series resistor R1 will extend the output current range of the device by sharing the total power dissipation between R1 and the regulator. VI Min b VO b 2.0V R1 e IL Max a IQ TL/H/10051 - 8 Note 1: To specify an output voltage, substitute voltage value for ``00''. Note 2: Bypass capacitors are recommended for optimum stability and transient response and should be located as close as possible to the regulator. (2) where: IQ is the regulator quiescent current. 8 9 LM78L00 Series 3-Terminal Positive Voltage Regulators Physical Dimensions inches (millimeters) Order Number LM78L05ACZ, LM78L09ACZ, LM78L12ACZ, LM78L15ACZ, LM78L62ACZ or LM78L82ACZ NS Package Number Z03A 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 systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. 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