The LM78S40 is a monolithic regulator subsystem consisting of all the active building blocks necessary for switching regulator systems. The device consists of a temperature-compensated voltage reference, a duty-cycle controllable oscillator with an active current limit circuit, an error amplifier, high current, high voltage output switch, a power diode, and an uncommitted operational amplifier.
LM78S40 can drive external NPN or PNP transistors when currents in excess of 1.5A or voltages in excess of 40V are required. The device can be used for step-down, step-up, or inverting switching regulators as well as for series pass regulatory systems and works extremely well in battery-operated systems.
78S40 Pinout
78S40 Pin Configuration
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | DIODE CATHODE | Diode Cathode Pin |
| 2 | DIODE ANODE | Diode Anode Pin |
| 3 | EMITTER SWITCH | Emitter Switch Pin |
| 4 | OP-AMP-OUT | Op-amp Output Pin |
| 5 | OP-AMP-SUPPLY | Op-amp Supply Pin |
| 6 | OP-AMP +1N | Op-amp Positive Input Pin |
| 7 | OP-AMP -1N | Op-amp Negative Input Pin |
| 8 | REFERENCE VOLTAGE | Reference Voltage Pin |
| 9 | COMPARATOR +IN | Comparator Positive Input Pin |
| 10 | COMPARATOR -IN | Comparator Negative Input Pin |
| 11 | GND | Ground Pin |
| 12 | TIMING CAPACITOR | Timing capacitor Pin |
| 13 | VIN | Input Voltage Pin |
| 14 | Ipk SENSE | Peak Current Sense Pin |
| 15 | DRIVER COLLECTOR | Driver Collector Pin |
| 16 | SWITCH COLLECTOR | Switch Collector Pin |
78S40 Key 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
Application
- Step-down, step-up or inverting switching regulators
You can download this datasheet for 78S40 1.5A Switching Regulator – Datasheet from the link given below:
