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National Semiconductor LM2678 High Efficiency 5A Step-Down Voltage Regulator Datasheet
The LM2678 series provides a monolithic high‑efficiency step‑down (buck) regulator capable of delivering up to 5 A. It integrates a low‑ON‑resistance DMOS power switch, internal oscillator, thermal shutdown, current limiting and an ON/OFF control input.
The device is offered in fixed 3.3 V, 5 V and 12 V versions as well as an adjustable version, with a wide input voltage range of 8 V to 40 V and operation from –40 °C to 125 °C. Typical applications include system pre‑regulators, battery chargers and other high‑efficiency power supplies.
National Semiconductor LM2678 specifications
| Output Voltage (fixed versions) | 3.3 V, 5 V, 12 V |
|---|---|
| Adjustable Output Range | 1.2 V to 37 V |
| Maximum Output Current | 5 A |
| Efficiency | up to 92 % |
| Input Voltage Range | 8 V to 40 V |
| Standby Quiescent Current (OFF) | 50 pA |
| Switching Frequency | 260 kHz (fixed) |
| Operating Temperature Range | -40 °C to 125 °C |
Source: National Semiconductor LM2678 High Efficiency 5A Step-Down Voltage Regulator Datasheet
All National Semiconductor LM2678 documents by type
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the input voltage range for the LM2678?
The LM2678 operates with an input voltage between 8 V and 40 V.
From: National Semiconductor LM2678 High Efficiency 5A Step-Down Voltage Regulator Datasheet
How much standby current does the LM2678 draw when OFF?
When the regulator is turned OFF, it draws only 50 pA of standby current.
From: National Semiconductor LM2678 High Efficiency 5A Step-Down Voltage Regulator Datasheet
What is the standby current when the regulator is turned off?
The standby quiescent current is 50 pA.
What is the internal switching frequency of the LM2678?
The regulator uses a fixed 260 kHz oscillator.