LM78S40

Features:

Step-up, step-down or inverting switching regulators
Output adjustable from 1.25V to 40V
Peak currents to 1.5A without external transistors
Operation from 2.5V to 40V input
Low standby current drain
80 dB line and load regulation
High gain,high current,independent op amp
Pulse width modulation with no double pulsing




Pinout






Specifications

Storage Temperature Range
Ceramic DIP −65˚C to + 175˚C
Molded DIP −65˚C to + 150˚C
Operating Temperature Range
Extended (LM78S40J) −55˚C to + 125˚C
Industrial (LM78S40N) −40˚C to + 125˚C
Commercial (LM78S40CN) 0˚C to + 70˚C
Lead Temperature
Ceramic DIP (Soldering, 60sec.) 300˚C
Molded DIP (Soldering,10sec.) 265˚C
Internal Power Dissipation (Note2) (Note3)
16L-Ceramic DIP 1.50W
16L- Molded DIP1.04W
Input Voltage from V_IN to GND 40V
Input Voltage from V⁺ (Op Amp)
to GND40V
Common Mode Input Range
(Comparator and Op Amp) −0.3 to V+

Output Current	1500 mA
Input Min Voltage	2.5 Volt
Input Max Voltage	40 Volt
Output Min	1.245 Volt
Output Max	Undefined Volt
Frequency Min	0.100, 0.1 kHz
Frequency Max	100 kHz
On/Off Pin	No
Error Flag	No
SoftStart	No
Sync Pin	No
Inverting	Yes
Flyback	Yes
RegType	Switching Regulator
Temperature Min	-55 deg C
Temperature Max	125 deg C
Adjustable Output	Yes
Adj Switch Frequency	Yes
PWM Mode	Voltage
Topology	Buck, Boost, Flyback, Inverting
Special Features	Integrated 1.5A diode, uncommitted op amp
Step-Down	Yes
Multiple Output Capability	Yes
Output Voltage	Undefined Volt
Output Range	1.245V min
Switching Frequency	100 kHz
Feedback Voltage	1.245 Volt
Regulator Family	Undefined
Synchronous Rectification	No
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Description

The LM78S40 is a monolithic regulator subsystem consisting of all the active building blocks necessary for switching regu-lator systems.The device consists of a temperature com-pensated voltage reference,a duty-cycle controllable oscilla-tor with an active current limit circuit,an error amplifier,high current,high voltage output switch,a power diode and an uncommitted operation alamplifier.The device can drive ex-ternal NPN or PNP transistors when currents in excess of 1.5A or voltages in excess of 40V arere quired.The device can be used for step-down,step-up or inverting switching regulators as well as for series pass regulators.It features wide supply voltage range,low standby power dissipation, high efficiency and lowd rift.It is useful for any stand-alone, low part counts witching system and work sextremely well in battery operated systems.