LM78L00

LM78L00 Series 3-Terminal Positive Voltage Regulators June 1989 LM78L00 Series 3-Terminal Positive Voltage Regulators General Description 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 Features 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 Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Storage Temperature Range Operation Junction Temperature Range Commercial (LM78L00AC) b 65 C to a 150 C Lead Temperature TO-92 Package SO-8 (Soldering 10 sec ) Power Dissipation Input Voltage 5 0V to 15V ESD Susceptibility 265 C Internally Limited 35V to be determined 0 C to a 125 C 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 Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 7 0V s VI s 20V 8 0V s VI s 20V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100V 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 8 0V s VI s 20V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 8 0V s VI s 18V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 41 40 49 17 140 b 0 65 Conditions Min 48 Typ 50 55 45 11 50 Max 52 150 100 60 30 5 25 5 25 Units V mV mV 7 0V s VI s 20V 7 0V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 4 75 4 75 20 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D V O VDO Ipk IOS D VO D T 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 VO VR LINE Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 8 5V s VI s 20V 9 0V s VI s 20V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100 mA 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 8 0V s VI s 20V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 10V s VI s 20V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 40 50 46 17 140 b 0 75 Conditions Min 5 95 Typ 62 65 55 13 60 Max 6 45 175 125 80 40 65 65 Units V mV mV 8 5V s VI s 20V 8 5V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 5 90 5 90 20 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D VO VDO Ipk IOS D VO D T 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 Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 11V s VI s 23V 12V s VI s 23V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100 mA 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 12V s VI s 23V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 12V s VI s 22V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 39 60 45 17 140 b0 8 Conditions Min 7 87 Typ 82 80 70 15 80 Max 8 53 175 125 80 40 85 86 Units V mV mA 11V s VI s 23V 11V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 78 78 21 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D V O VDO Ipk IOS D VO D T 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 VO VR LINE Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 11 5V s VI s 24V 13V s VI s 24V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100 mA 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 11 5V s VI s 24V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 15V s VI s 25V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 38 70 44 17 140 b0 9 Conditions Min 8 64 Typ 90 90 100 20 10 Max 9 36 200 150 90 45 9 45 9 45 Units V mV mV 11 5V s VI s 24V 11 5V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 8 55 8 55 21 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D V O VDO Ipk IOS D VO D T 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 VO VR LINE Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 14 5V s VI s 27V 16V s VI s 27V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100 mA 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 16V s VI s 27V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 15V s VI s 25V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 37 80 42 17 140 b1 0 Conditions Min 11 5 Typ 12 120 100 20 10 Max 12 5 250 200 100 50 12 6 12 6 Units V mV mV 14 5V s VI s 27V 14 5V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 11 4 11 4 21 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D V O VDO Ipk IOS D VO D T 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 VO VR LINE Parameter Output Voltage Line Regulation TJ e 25 C TJ e 25 C 17 5V s VI s 30V 20V s VI s 30V VR LOAD Load Regulation TJ e 25 C 1 0 mA s IO s 100 mA 1 0 mA s IO s 40 mA VO Output Voltage (Note 2) Quiescent Current Quiescent Current Change Noise Ripple Rejection Dropout Voltage Peak Output Output Short Circuit Current Average Temperature Coefficient of Output Voltage With Line With Load 20V s VI s 30V 1 0 mA s IO s 40 mA TA e 25 C 10 Hz s f s 100 kHz f e 120 Hz 18 5V s VI s 28 5V TJ e 25 C TJ e 25 C TJ e 25 C IO e 5 0 mA 34 90 39 17 140 b1 3 Conditions Min 14 4 Typ 15 130 110 25 12 Max 15 6 300 250 150 75 15 75 15 75 Units V mV mV 17 5V s VI s 30V 17 5V s VI s VMax 1 0 mA s IO s 40 mA 1 0 mA s IO s 70 mA 14 25 14 25 22 V mA mA mV dB V mA mV C IQ D IQ 55 15 01 NO D VI D V O VDO Ipk IOS D VO D T 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 TO-92 Typ iJC Max iJC Typ iJA 160 Max iJA 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 i 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 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 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 Regulator power dissipation at maximum input voltage and maximum load current is now PD Max e (V1 b VO) IL Max a V1 IQ 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 25 b 15 b 2 8 j 240X e 30 a 4 3 34 3 (5) (3) TL H 10051 – 5 FIGURE 2 TO-92 Thermal Equivalent Circuit (Lead at other than Ambient Temperature) High Dissipation Applications 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 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 where IQ is the regulator quiescent current (2) 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 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 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