PCA9430 NTC Temperature monitoring and control Charging

[Bimalsinh]

Hello,

We are working on a product design where we have used PCA9430 PMIC along with other NFC WLC solutions. We have following query and requires your feedback for the same.

- Our Requirement of product is to suspend the battery charging when NTC temperature is below 0C and above 45C.

- But while looking into the PCA9430 datasheet it seems it has internal JEITA compliant temperature thresholds cold as below<0C (which is ok) and Hot as >60C. Is it configurable?

- What should be done if we require to suspend the charging once it crosses >45C. one possible option is that MCU reads the NTC temperature from PCA9430 and suspend the charging, But is it possible to achieve through PCA9430?

- We did the preliminary test on our prototype and found that PCA9430 didn't stopped the charging even when temperature is >60C. even though the NTC_EN was enabled. Can you provide which are the critical parameters to be set in order to achieve the functionality?

Awaiting your positive feedback as soon as possible.

[KaiLi]

Hello @Bimalsinh 

Could you share with us the schematic? Let's check how to control PCA9430.

BR

kelly

[Bimalsinh]

Hello KellyLi,

In the schematic of PMIC, PCA9430 for NTC there is no specific requirement i think. It's just connection to NTC resistor external. Please find the related snap below. Here the PCA9430 is connected to MCU through I2C.

Awaiting your valuable feedback here.

Let us know if you need more details we can move to E-mail communication.

[KaiLi]

Hello @Bimalsinh 

Figure 9 in the datasheet clearly describes this feature, so it is logical to still charge between 45-60 degrees. But it is wrong to still charge when the temperature is above 60 degrees. But there is a point that needs to be noted. The temperature of the NTC is fed back to the inside of the chip, which is actually transmitted through voltage. Therefore, it is recommended that you confirm that when the temperature reaches 60 degrees or above, measure the voltage of the NTC. The voltage (TP17 in your design) at this time should be less than 200mV. 

In addition, it is recommended that ADC configurate continuous conversion(01) and enable averaging.

BR

kelly

[Bimalsinh]

Hello,

Thanks for the feedback, we were able to check that the charging is suspended when temperature is approximately above 60C.

But as i mentioned earlier, is there a way to configure this temperature threshold from 60C to 45C?

[KaiLi]

Hello @Bimalsinh 

This feature is only on and off, the temperature is not adjustable, and only the charging voltage and current are adjustable.

BR

kelly