Charging circuit and charging method of battery

Patent metadata

Field	Value
Publication number	US-9716404-B2
Application number	US-201414576185-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 24, 2013
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A charging circuit and a charging method of a battery are disclosed. The charging circuit provides a charging current to charge the battery. The charging circuit includes a charging control module, a current detecting module and a compensation module. The charging control module provides a charging voltage. The current detecting module detects the charging current, and generates a detecting voltage according to the charging current. The compensation module detects the charging voltage, and provides a feedback voltage to the charging control module according to the detecting voltage and the charging voltage.

First claim

What is claimed is:

1. A charging circuit of a battery, comprising:
a charging control module providing a charging voltage;
a current detecting module detecting a charging current and generating a detecting voltage according to the charging current; and
a compensation module detecting the charging voltage and providing a feedback voltage to the charging control module according to the detecting voltage and the charging voltage,
wherein the compensation module further includes:
a buffer receiving and buffering the charging voltage, and providing the buffered charging voltage to an operational amplifier;
the operational amplifier receiving the detecting voltage and the buffered charging voltage, and subtracting the detecting voltage from the buffered charging voltage to obtain the feedback voltage;
a first resistor electrically connected between a first input terminal of the operational amplifier and the current detecting module;
a second resistor electrically connected between the first input terminal of the operational amplifier and an output terminal of the operational amplifier;
a third resistor electrically connected between an output terminal of the buffer and a second input terminal of the operational amplifier; and
a fourth resistor electrically connected between the second input terminal of the operational amplifier and a ground potential.

2. The charging circuit according to claim 1 , wherein the charging control module selectively provides a constant charging current or a fluctuant charging current to the battery according to the feedback voltage.

3. The charging circuit according to claim 1 wherein when the feedback voltage is larger than or equal to a saturated charging level, the charging control module is switched from providing a constant charging current to providing a fluctuant charging current to the battery.

4. The charging circuit according to claim 1 , wherein the current detecting module includes:
a current detecting resistor, wherein the charging current flows through the current detecting resistor and generates a potential difference between two ends of the current detecting resistor; and
a differential amplifier amplifying the potential difference at two ends of the current detecting resistor to provide the detecting voltage.

Assignees

• Asustek Comp Inc

Inventors

• Tu Wei-Chen
• Tsai Ming-Ting
• Wu Yii-Lin
• Hung Hsiang-Jue

Classifications

• H02J7/96

  in response to battery voltage · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/92 Primary

  with prioritisation of loads or sources · CPC title

• H02J7/041

  Electricity · mapped topic

• Y02B40/90

  Cross-Sectional Technologies · mapped topic