MAX77751

3.15A USB-C Autonomous Charger

for 1-Cell Li+ Batteries

www.maximintegrated.com

Maxim Integrated | 19

CHGIN

SYS

LX

PGND

BYP

BATT

INPUT CONTROL

10µF

16V

0603

2x10µF

10V

0603

10µF

10V

0603

0.47µH

BYP

BATT

JUNCTION

TEMPERATURE

SENSOR TEMP

SYS

DRV_OUT

1.3MHz

BUCK CONTROLLER

CHARGE CONTROLLER

REVERSE BOOST

CONTROLLER

CHARGE

TIMER

2.2µF

16V

0603

WATCHDOG

UP TO 3.0A OF

CHARGE

CURRENT AND

UP TO 6A OF

DISCHARGE

CURRENT

BATT

GND

+

BST

0.1µF

6.3V

0402

22µF

16V

0603

MAX77751

UP TO +13.7V OPERATING

UP TO 3.0A INPUT CURRENT

Figure 2. Battery Charger Detailed Functional Diagram

Detailed Description

The MAX77751 includes a full-featured switch-mode charger for a one-cell lithium ion (Li+) or lithium polymer (Li-polymer)

battery. As shown in Figure 2, the current limit for the CHGIN input is automatically configured allowing the flexibility for

connection to either an AC-to-DC wall charger or a USB port.

The synchronous switch-mode DC-DC converter utilizes a high 1.3MHz switching frequency, which is ideal for portable

devices because it allows the use of small components while eliminating excessive heat generation. The DC-DC has both

a buck and a boost mode of operation. When charging the battery, the converter operates as a buck. The DC-DC buck