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Overview

Description

The ISL81401 and ISL81401A are 4-switch synchronous buck-boost controller with peak and average current sensing and monitoring at both ends. The ISL81401 is a bidirectional device that can conduct current in both directions while the ISL81401A is an unidirectional device. The ISL81401 and ISL81401A use the proprietary buck-boost control algorithm with valley current modulation for Boost mode and peak current modulation for Buck mode control. The ISL81401 and ISL81401A have four independent control loops for input and output voltages and currents. Inherent peak current sensing at both ends and cycle-by-cycle current limit of this family of products ensures high operational reliability by providing instant current limit in fast transient conditions at either ends and in both directions. It also has two current monitoring pins at both input and output to facilitate Constant Current (CC) limit and other system management functions. CC operation down to low voltages avoids any runaway condition at over load or short-circuit conditions. In addition to multilayer overcurrent protection, it also provides full protection features such as OVP, UVP, OTP, and average and peak current limit on both input and output to ensure high reliability in both unidirectional and bidirectional operation. The IC is packaged in a space conscious 32 Ld 5mmx5mm QFN package to improve thermal dissipation and noise immunity. The unique DE/Burst mode at light-load dramatically lowers standby power consumption with consistent output ripple over different load levels.

Features

  • Single inductor 4-switch buck-boost controller
  • On-the-fly bidirectional operation with independent control of voltage and current on both ends
  • Proprietary algorithm for smoothest mode transition
  • MOSFET drivers with adaptive shoot-through protection
  • Wide input voltage range: 4.5V to 40V
  • Wide output voltage range: 0.8V to 40V
  • Supports pre-biased output with SR soft-start
  • Programmable frequency: 100kHz to 600kHz
  • Supports parallel operation current sharing with cascade phase interleaving
  • External sync with clock out or frequency dithering
  • External bias for higher efficiency supports 5V - 36V input
  • Output and input current monitor
  • Selectable PWM mode operation between PWM/DE/Burst modes
  • Accurate EN/UVLO and PGOOD indicator
  • Low shutdown current: 2.7µA
  • Complete protection: OCP, SCP, OVP, OTP, and UVP
    • Dual-level OCP protection with average current and pulse-by-pulse peak current limit
    • Selectable OCP response with either hiccup or constant current mode
    • Negative pulse-by-pulse peak current limit

Comparison

Applications

Documentation

Type Title Date
Datasheet PDF 3.39 MB
White Paper PDF 759 KB 日本語 , 简体中文
White Paper PDF 351 KB 日本語 , 简体中文
Application Note PDF 509 KB
Application Note PDF 397 KB
5 items

Design & Development

Software & Tools

Software Downloads

Type Title Date
PCB Design Files Log in to Download ZIP 4.30 MB
Software & Tools - Other Log in to Download XLSX 1.92 MB
2 items

Boards & Kits

Models

ECAD Models

Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on the CAD Model links in the Product Options table. If a symbol or model isn't available, it can be requested directly from SamacSys.

Diagram of ECAD Models

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Support Communities

  1. ISL81401EVAL1Z size dimension

    So, recently i found this ISL81401EVAL1Z DC/DC buck boost. But, i cant find any size dimension of this module. Does anyone know what size dimension this module is?

    Sep 18, 2022
  2. ISL81601 / ISL81401

    Hello! Help me please!I want to use ISL81601 or ISL81401 as a bi-directional battery charger-discharger! The most difficult thing for me is to determine the maximum discharge current! I want to select a choke and mosfet transistors to operate on a 50A (12V) load. My battery is ...

    Dec 12, 2023
  3. ISL81601 UPS with low voltage battery/capacitor

    Hello! I would like build a UPS with only 1 cell of Li-Ion battery (max. 4.2V) or supercapacitor (max. 2.7V). System bus would be 5V. According to the datasheet the minimum voltage on Vin should be minimum 4.5V, so I can't use the Vin side ...

    Jan 7, 2024

FAQs

  1. What does a true bidirectional buck-boost controller do?

    ... manage and control the energy flow.          Now on the right-hand side we tackle the same design using a bidirectional buck-boost controller such as ISL81401, ISL81601 or ISL81801. And as you can see only one set of electronics serves the purpose of both charging and discharging which significantly lowers ...

    Oct 21, 2020