9.2.1 Typical Application

The typical application in this section includes a standalone charger without power path.

2.2 …F

2.2 …F

47 nF

REGN

10 …F

VBUS

REGN

REGN

ICHG

VSET

GND

Q3

Q1

Q2

BAT

TS

PGND

BTST

SW

VBUS

2.2 …F

PMID

REGN

STAT

Figure 9-1. Typical Application Diagram (1-µH inductor is recommended)

9.2.1.1 Design Requirements

Table 9-1. Design Requirements

PARAMETER

VALUE

Input Voltage

4.1V to 6.2V

Input Current

2.0A

Fast Charge Current

2.0A

Battery Regulation Voltage

4.1V/4.2V/4.35V/4.4V

9.2.1.2 Detailed Design Procedure

9.2.1.2.1 Charge Voltage Settings

Battery charge voltage is set by a resistor connected at the VSET pin. When the REGN LDO startup conditions

are met, and before the REGN LDO powers up, the internal VSET detection circuit is enabled to detect VSET pin

resistance and set battery charge voltage accordingly. The VSET detection circuit is disabled after detection is

complete and changing resistance values on the fly does not change the battery charge voltage. VSET detection

is reenabled once the REGN LDO is recycled.

9.2.1.2.2 Charge Current Setting

The charger current is set by the resistor value at the ICHG pin according to the equation below:

ICHG typical characteresitc curve is shown in Figure 7-6.

9.2.1.2.3 Inductor Selection

The 1.2-MHz switching frequency allows the use of small inductor and capacitor values to maintain an inductor

www.ti.com

BQ25302

SLUSCZ3 – OCTOBER 2020

Copyright © 2020 Texas Instruments Incorporated

Submit Document Feedback

21

Product Folder Links: BQ25302