Other NXP Productsのトピックpcf8563 Current Drain

pcf8563 Current Drain

fav — Fri, 11 Aug 2023 23:22:11 GMT

I'm using the PCF8563T to interrupt a cpu every 24 hrs. Vdd is 3.3v and I'm using a 32.768 kHz external crystal which is sufficiently accurate for my app with no compensation. The configuration works as expected with no problems. The issue I have is that with no I2C or interrupt activity and no clock outputs, the chip is drawing about 1.6ma while internally maintaining the time. Is this normal or am I overlooking something in the configuration setup to achieve lower current drain?

Thanks for any assistance with this.

Frank

Re: pcf8563 Current Drain

guoweisun — Fri, 11 Aug 2023 23:28:53 GMT

Can you share with your schematic?

Re: pcf8563 Current Drain

fav — Sat, 12 Aug 2023 16:10:44 GMT

Thanks for responding.

I misstated the current draw in my original post. 1.6 ma is the current draw from a 12v to 3.3v dc-dc converter. The current draw, as noted in the schematic, is 5.1 ma. I have tried configurations with no interrupt and with I2C connections removed after configuring the RTC, but the high current drain remains.

Re: pcf8563 Current Drain

guoweisun — Mon, 14 Aug 2023 01:03:23 GMT

This's impossible, how many boards did you test? same result?

Re: pcf8563 Current Drain

fav — Mon, 14 Aug 2023 17:58:50 GMT

I was unable to try another meter over the weekend, but today I used a different meter and the current draw was about 300nA. Sorry for the oversight and thank you for responding.

Frank