Battery Interface & Coulomb Counter on MC34708

[T_I]

Hi, We are working on a new design according to i.MX53QSB-R. I have 2 questions for Battery Interface & Coulomb Counter on MC34708.

question 1

BATT, BATTISNSCCN, CHRGFB, BATTISNSN, BATTISNSCCP, BATTISNSP, ITRIC, BP, BPSNS connect VCC_BP.

I think that I don't have to connect all. Don't I need to tie only BP and BATT to VCC_BP?

question 2

TRICKLESEL tied to VCOREDIG and PRETMR tied to GND. But I don't use Trickle Charge & Standalone Charge.

Is it any problem if floating PRETMR and TRICKLESEL?

What do you think?

[T_I]

Thank you for your quick reply.

I design it as you taught it.

Thanks!

[DarylBergstrom]

Reply to Question 1.
You should connect BATT, BATTISNSCCN, CHRGFB, BATTISNSN, BATTISNSCCP, BATTISNSP, BP and BPSNS together with VCC_BP. You don’t need to connect the ITRIC pin as this is only used for trickle charging a battery.

Reply to Question 2.
You can float both pins TRICKLESEL and PRETMR. Please ensure that you have the GBAT pin grounded so that the MC34708 doesn’t detect that an Mbatt FET is present.