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NCP1421

ONNCP1421

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The bare IC used on the EVB if you want to design a custom PCB or evaluate the chip without the full evaluation board.
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Overview

The NCP1421 is a monolithic, micro-power high-frequency step-up DC-DC converter designed for small portable electronic devices. It features an integrated Synchronous Rectifier for high efficiency and a 'True-Cutoff' function that completely isolates the output from the input during shutdown. With a low 8.5uA quiescent current and a guaranteed startup at 1.0V, it is optimized for single or dual-cell alkaline and NiMH battery applications.

Why Choose This Part

The NCP1421 offers a 1.2MHz switching frequency which allows for the use of small, low-profile inductors and capacitors. Its built-in 'Ring-Killer' reduces EMI by eliminating high-frequency ringing in discontinuous conduction mode, and the synchronous rectification eliminates the need for an external Schottky diode.

Applications

Single/Dual Cell Alkaline Devices
Boosting voltage from 1.0V or 1.5V sources to a stable 3.3V or 5.0V rail for microcontrollers and sensors.
Battery-Powered Wearables
Utilizing the Micro8 package and low quiescent current to extend battery life in space-constrained designs.
Handheld Portable Electronics
Providing up to 600mA of output current for small handheld instruments and consumer gadgets.
Low-Battery Detection Systems
Leveraging the integrated low-battery detector with an open-drain output for system-level power monitoring.

Key Specifications

Contents Board(s)
Main Purpose DC/DC, Step Up
Voltage - Input 3V
Current - Output 600mA
Outputs and Type 1 Non-Isolated Output
Voltage - Output 3.3V or 5V
Regulator Topology Boost
Utilized IC / Part NCP1421
Frequency - Switching 1.2MHz

Getting Started

To evaluate the NCP1421, designers should focus on the PCB layout of the Micro8 package to minimize parasitic resistance between the inductor and the LX pin. Ensure that the feedback resistor network is placed close to the FB pin to maintain high accuracy of the output voltage which can be adjusted from 1.5V to 5.0V.

Also Consider

MCP1640 MCHPMicrochip - Alternative synchronous boost regulator with a similar low startup voltage of 0.65V.
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