MAX77751

3.15A USB-C Autonomous Charger

for 1-Cell Li+ Batteries

www.maximintegrated.com

Maxim Integrated | 33

Figure 11. D+/D- Connections in a Reference System

Capacitor Selection

All capacitors should be X5R dielectric or better. Be aware that multi-layer ceramic capacitors have large voltage

coefficients. Before selecting capacitors, check for sufficient voltage rating and derated capacitance at the max operating

voltage condition. Table 5 shows the capacitors to select after considering the derating and operating voltage.

Table 5. Capacitor Selections

PIN

TYPE

CHGIN Capacitor

2.2µF/16V

BYP Capacitor

10µF + 22µF/16V

SYS Capacitor

2x10µF/10V

BATT Capacitor

10µF/10V

VDD Capacitor

2.2µF/10V

PVL Capacitor

2.2µF/10V

BST Capacitor

100nF/6.3V

Thermal Considerations

If the system that includes the MAX77751 can read the battery temperature, the temperature can be controlled by

charging is disabled by pulling the ITOPOFF pin low. Figure 12 shows a recommended system diagram where the MCU

has an ADC to sense the temperature, a GPIO output connected to ITOPOFF to enable or disable charging, and a GPIO

input connected to INOKB to check the presence of a valid charger. Note that the GPIO output should be an open-drain

type. In this system configuration, if the MCU judges the temperature is too high, the MCU should pull the GPIO output

low to disable charging. It is important to check if a valid charger is present through the INOKB signal before disabling

charging. Pulling ITOPOFF low when the INOKB signal is high (i.e., inactive) could affect the TOPOFF current sensing.

Meanwhile, if the temperature goes back to normal, the MCU should make the GPIO be high impedance state to enable

charging.

MAX77751

CC2

CC1

INOKB

DP

DN

CHGIN

MCU

CC1

USB TYPE-C

CONNECTOR

CC2

D+

D-

D+

D-

GPIO

GPIO