NCP1421EVB: 3.3 or 5V @ 600mA, 1 ~ 5V in, Boost


NCP1421 is a monolithic, micro-power, high-frequency, step-up switching converter IC designed for battery operated hand-held electronic products with up to 600 mA loading. It integrates a synchronous rectifier (Sync-Rect) to improve efficiency and to eliminate the external Schottky Diode.

The NCP1421's high switching frequency (up to 1.2 MHz) allows for a low profile, small sized inductor and output capacitor to be used. When the device is disabled, the internal conduction path from the battery to the load is fully blocked, which isolates the load from the battery. This True-Cutoff function reduces the shutdown current to typically only 50nA.

A Ring-Killer is also integrated to eliminate high-frequency ringing in discontinuous conduction mode. Finally, a Low-Battery Detector, Logic-Controlled Shutdown, Cycle-by Cycle Current Limiting and Thermal Shutdown provide value-added features for various battery operated applications. With all these functions ON, the quiescent supply current is typically only 8.5 µA. This device is available in the compact and low profile Micro8 package.


Manufacturer ON Semiconductor
Category AC/DC and DC/DC Conversion
Sub-Category DC/DC SMPS - Single Output
Eval Board Part Number NCP1421EVBOS-ND
Eval Board Supplier ON Semiconductor
Eval Board Normally In Stock
Topology Step Up
Outputs and Type 1 Non-Isolated
Voltage Out: Factory Set 3.3 V
5 V
Current Out 600 mA
Voltage In 1 ~ 5 V
Efficiency @ Conditions >80%, 3.2 ~ 3.8V in, 3.5V @ 200 mA
>76%, 3.2 ~ 4.2V in, 3.5V @ 600 mA
Voltage Out Range 1.5 ~ 5 V
Features Current Limit (Adj. or Fixed)
Shutdown, Enable, Standby
Soft Start
Thermal Protection
Switching Frequency Up to 1.2 MHz
Standby Current [Typical] 1.3 µA
Quiescent Current [Typical] 8.5 µA
Component Count + Extras 13 + 6
Internal Switch Yes
Design Author ON Semiconductor
Application / Target Market Digital Cameras
Flashlight / Torch
Portable Devices
Standby Current [Maximum] 3 µA
Quiescent Current [Maximum] 14 µA
Main I.C. Base Part NCP1421
Date Created By Author 2004-11
Date Added To Library 2016-04

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