These voltage regulators are monolithic integrated circuits designed as fixedvoltage regulators for a wide variety of applications including local, oncard regulation. These regulators employ internal current limiting, thermal shutdown, and safearea compensation. With adequate heatsinking they can deliver output currents in excess 1.0 A. Although designed primarily as a fixed voltage regulator, these devices can be used with external components to obtain adjustable voltages and currents.
Output Current in Excess A No External Components Required Internal Thermal Overload Protection Internal Short Circuit Current Limiting Output Transistor SafeArea Compensation Output Voltage Offered in 2% and 4% Tolerance Available in Surface Mount D2PAK and Standard 3Lead Transistor Packages Previous Commercial Temperature Range has been Extended to a Junction Temperature Range to +125°C
T SUFFIX PLASTIC PACKAGE CASE 221A Heatsink surface connected to Pin 2.
Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin 2.
Device MC78XXACT Insertion Mount MC78XXCD2T XX indicates nominal voltage. 4% Surface Mount +125 125°C Surface Mount Insertion Mount Output Voltage Tolerance Operating Temperature Range Package
A common ground is required between the input and the output voltages. The input voltage must remain typically 2.0 V above the output voltage even during the low point on the input ripple voltage. XX, These two digits of the type number indicate nominal voltage. * Cin is required if regulator is located an appreciable distance from power supply filter. CO is not needed for stability; however, it does improve transient response. Values of less than 0.1 µF could cause instability.
Rating Input Voltage 18 V) Input Voltage (24 V) Power Dissipation Case = 25°C Thermal Resistance, JunctiontoAmbient Thermal Resistance, JunctiontoCase Case = 25°C Thermal Resistance, JunctiontoAmbient Thermal Resistance, JunctiontoCase Storage Junction Temperature Range Operating Junction Temperature
LAT Q17 Vin R24 50 LAT Q18 Q19 QNPN C3 Q10 QNPN 100 Q7 QNPN k D1 Zener k Q8 QNPN k Q14 QNPN P N+ QNPN 6 Q13 QNPN k Q4 QNPN Q3 QNPN P D2 Zener k Q20 QNPN R15 680
ELECTRICAL CHARACTERISTICS (Vin = 500 mA, TJ = Tlow to Thigh [Note 1], unless otherwise noted.)
MC7805C/LM340T5 Characteristic Output Voltage (TJ = 25°C) Output Voltage W) 7.0 Vdc Vin 20 Vdc 8.0 Vdc Vin 20 Vdc Line Regulation (Note 2) 7.5 Vdc Vin 20 Vdc, A 8.0 Vdc Vin 12 Vdc Load Regulation (Note 1.5 A (TA = 25°C) Quiescent Current Quiescent Current Change 7.0 Vdc Vin 25 Vdc 1.0 A (TA = 25°C) Ripple Rejection 8.0 Vdc Vin 18 Vdc, 120 Hz Dropout Voltage (IO = 25°C) Output Noise Voltage (TA f 100 kHz Output Resistance = 1.0 kHz Short Circuit Current Limit (TA = 25°C) Vin = 35 Vdc Peak Output Current (TJ = 25°C) Average Temperature Coefficient of Output Voltage Symbol 4.75 Regline Regload Vn rO ISC Imax TCVO dB Vdc µV/VO m A mV/°C mA mV Min 4.8 Typ 5.0 Max 5.2 Unit Vdc
ELECTRICAL CHARACTERISTICS (Vin TJ = Tlow to Thigh [Note 1], unless otherwise noted.)
MC7805AC/LM340AT5 Characteristic Output Voltage (TJ = 25°C) Output Voltage W) 7.5 Vdc Vin 20 Vdc Line Regulation (Note 2) 7.5 Vdc Vin 25 Vdc, mA 8.0 Vdc Vin 12 Vdc, A 8.0 Vdc Vin 12 Vdc, 25°C 7.3 Vdc Vin 20 Vdc, = 25°C Load Regulation (Note 750 mA Quiescent Current Quiescent Current Change 8.0 Vdc Vin 25 Vdc, mA 7.5 Vdc Vin 20 Vdc, 1.0 A Ripple Rejection 8.0 Vdc Vin 18 Vdc, = 120 Hz, 500 mA Dropout Voltage (IO = 25°C) Symbol VO Regline Regload VO dB Vdc mA mV Min 4.9 4.8 Typ 5.0 Max 5.1 5.2 Unit Vdc mV
NOTES: 1. Tlow = 40°C for LM340ATXX, LM340TXX Thigh = +125°C for LM340TXX 2. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used.