The LM2678 regulator is a monolithic integrated circuit that provides all of the active functions for a stepdown (buck) switching regulator capable of driving up to 5A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance DMOS power switch. The LM2678 consists of a fixed output voltage of 5V.
The LM2678 also has a built-in thermal shutdown, current limiting, and an ON/OFF control input that can power down the regulator to a low 50µA quiescent current standby condition. The output voltage is guaranteed to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.

LM2678 Pinout

LM2678 Pin Configuration
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | SWITCH OUT | Switch Output Pin |
| 2 | IN | Input Pin |
| 3 | C BOOST | C Boost Pin |
| 4 | GND | Ground Pin |
| 5 | NC | No Connection |
| 6 | FEEDBACK | Feedback Pin |
| 7 | ON/OFF’ | On/Complement Off Pin |
LM2678 Key Features
- 120 mΩ DMOS output switch
- 3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions
- 50µA standby current when switched OFF
- ±2%maximum output tolerance over full line and load conditions
- Wide input voltage range: 8V to 40V
- 260 KHz fixed frequency internal oscillator
- −40 to +125˚C operating junction temperature range
Application
- Simple to design, high efficiency (>90%) step-down switching regulators
- Efficient system pre-regulator for linear voltage regulators
- Battery chargers
You can download this datasheet for LM2678 5V 5A Step-Down Voltage Regulator – Datasheet from the link given below: