Product Introduction

Product parameters

Funtion：4A, Standalone Li-ion Battery Charger IC With Automatic Charge Current Adjustment

Opration Mode：Switch

Battery：single-cell lithium io, lithium polymer battery

Battery No.：1

Vout Range：0V-4.2V

Vin Range：4.83V to 28V

Max Charge Current：4A

Operating Current：1mA

Solar Panel charge：Yes

Chip Temperature Regulation：No

Package：SSOP10

Switching Frequency：300kHz

Chip Enable：No

On-chip Power MOSFET：No

General Descriptions:

The CN3781 is a PWM switch-mode lithium ion battery charger controller for 1 cell li-ion battery in a small package using few external components.

The CN3781 is specially designed for charging lithium ion batteries with constant current and constant voltage mode. In constant voltage mode, the regulation voltage can be fixed at 4.2V with ±1% accuracy, also can be adjusted upward with an external resistor. The constant charge current is programmable with a single current sense resistor. An on-chip circuit block can automatically adjust charge current based on the output capability of input supply, so CN3781 is ideally suited for the applications powered by the supply with limited output capability, such as USB port, etc.

Deeply discharged batteries are automatically trickle charged at 17.5% of the full-scale current until the cell voltage exceeds 66.5% of constant voltage. The charge cycle is terminated once the charge current drops to 16% of full-scale current, and a new charge cycle automatically restarts if the battery voltage falls below 95.5% of regulation voltage. CN3781 will automatically enter sleep mode when input voltage is lower than battery voltage.

Other features include under voltage lockout, battery over voltage protection, status indication.

CN3781 is available in a space-saving 10-pin SSOP package.

Applications:

l Power Bank

l Hand-held Equipment

l Battery-Backup Systems

l Portable Industrial and Medical Equipment

l Standalone Battery Chargers

Features:

l On-chip circuit block can automatically adjust charge current based on the output capability of input supply

l Suited for the applications powered by the supply with limited output capability, such as USB port, etc.

l Wide Input Voltage: 4.83V to 28V