LTC3421/3421f is a low-power synchronous boost converter with a maximum operating frequency of 3MHz. The input voltage range is 0.5V~4.5V, and the output voltage range is 2.4V~5.25V. It has synchronous rectification, output disconnect, inrush current limiting, low quiescent current, high efficiency, programmable current limit, programmable soft start, synchronous oscillator, manual or automatic burst mode, low battery comparator and other characteristics.
The LTC3421 is a step‑up DC/DC converter designed for portable applications such as handheld computers, cordless phones and GPS receivers. It offers up to 1.5 A continuous output current, very low quiescent current (12 µA in Burst Mode) and a programmable output voltage from 2.4 V to 5.25 V.
The device is supplied in a 4 mm × 4 mm QFN package, operates up to 3 MHz, and includes features like synchronous rectification (up to 96 % efficiency), programmable current limit, soft‑start, burst‑mode operation and a low‑battery comparator.
| Input Voltage Range | 0.5 V to 4.5 V |
|---|---|
| Adjustable Output Voltage | 2.4 V to 5.25 V |
| Maximum Continuous Output Current | 1.5 A |
| Quiescent Current (Burst Mode) | 12 µA |
| Efficiency (Synchronous Rectification) | up to 96 % |
| Operating Frequency | up to 3 MHz |
| Package | 24‑lead 4 mm × 4 mm Plastic QFN |
The device operates from 0.5 V up to 4.5 V input.
In Burst Mode the quiescent current is only 12 µA.
It can deliver up to 1.5 A of continuous output current.
Soft‑start time is calculated as t(ms) = C (µF) × 320.