TPS659113 RTC delay in IPNC DM81xx Platform

I knew Ti  employee Chris Meng has found the same problem on TPS659113 on IPNC app.

http://e2e.ti.com/support/power_management/pmu/f/43/t/220436.aspx

Best Regards

Jiger

Dear Biser,

What is the difference between the crystal oscillator and the TPS659113 built-in RC oscillator? how to confirm it?

Best Regards

Jiger

Dear Biser Gatchev-XID:

We are using IPNC DM8127 platform, we found that TPS659113 RTC time is no accuracy.  We are using external crystal, crystal is 32.768 kHz.

We use a button cell (3.3 V ) for our DM81xx board, the diagram as below:

We have set bit 5, CK32K_CTRL in the DEVCTRL_REG register of the TPS659113, now the bit5 is 0,that mean is We are using external crystal. And the button cell is 3.227 V .

By the way, I found the RTC time lost after power off the system sometime . But I add a capacitance in to TPS659113’s D7 pin, this lost is never happen. However, the time is still no accuracy.

Dose anybody met this problem?

Biser, Is there an issue with the internal RC ckt for the TPS65911x?

You mentioned to 'make sure you use external crystal and not internal RC'.

Thanks.