topic PCF2131TFY Battery Draw in Other NXP Products

PCF2131TFY Battery Draw

chadl — Mon, 14 Jul 2025 20:26:38 GMT

A product using the PCF2131TFY is having intermittent issue where some boards are depleting their batteries in a matter of days. The batteries installed are CR2032. Are there any considerations to take or look into for diagnosing this issue? Or are there known issues with this part?

Re: PCF2131TFY Battery Draw

guoweisun — Tue, 15 Jul 2025 02:02:41 GMT

Can you share your schematic here?

Re: PCF2131TFY Battery Draw

chadl — Tue, 15 Jul 2025 12:13:22 GMT

I sent you a private message.

Re: PCF2131TFY Battery Draw

guoweisun — Mon, 21 Jul 2025 01:11:19 GMT

For some unused pins please follow below suggestions setting:

Customer can leave CLKOUT and TS1-4 pins open when not using them in application.

Customer can set CLKOUT pin to be in high-Z mode by setting CLKOUT_ctl register (13h) bit[2:0] = 111b. And set TS1-4 pin are to be inactive pins by setting Control_4 register (03h) bit [7:4] = 0000b and Control_5 register (04h) but [7:4] = 0000b.

Re: PCF2131TFY Battery Draw

chadl — Mon, 28 Jul 2025 12:13:29 GMT

Turns out the issue is that there was some excess and uncleaned solder flux on all of the PCBs that was causing some excess current draw and the battery drain.