Over temperature current derating in the CYPD3175

[PaBe_4746231]

We are planning to use the CYPD3175 for one of our application as USB-A and USB-C charger. I would like to know if the external thermistor for the over temperature protection can be used to reduce the current in the USB-C and USB-A port by programming a custom firmware? If yes, can you point me to the proper API that can be used to read the temperature and set the current for each port?

Thanks

[Pranava_YN · Accepted solution]

Hi,

Yes, thermistor can be used to measure temperature and update PDOs accordingly such that PDOs with required current values are advertised based on temperature reading.

Please refer to uint16_t app_otp_get_sys_temp(uint8_t port, uint8_t therm_id) function defined in fault_handlers.c file to read thermistor voltage through internal ADC. You can continuously monitor the thermistor reading and change the PDOs according to requirement. Any change in PDOs would require renegotiation of the entire contract with the sink device.

Refer to Active Power Identification with Multiple PDOs  and dpm_update_src_cap_mask vaule  threads to dynamically change PDOs at runtime.

Regards,

Pranava

[PaBe_4746231]

Thanks for the information.