BQ24610: Fast charge safety timer

user6555887

Part Number: BQ24610

Dear sir:

When we used bq24610EVM to verify the circuit, we found that the charging safety timer did not work.The change point is Cttc 0.1uF-->0.047uF.

Battery charger does not stop charging after constant current charging for more than 5 hours.

Please help confirm！

Thank you！

over 3 years ago

0 Kedar Manishankar over 3 years ago

TI__Mastermind 24075 points

Hi,

When charge is in progress, can you take scope capture of TTC pin? Use small time scale so that the ramp on TTC is visible. This will tell us if the timer is counting or not.

0 user6555887 over 3 years ago in reply to Kedar Manishankar

Prodigy 230 points

Dear sir:

TTC waveform measurement is as follows

During measurement, the battery voltage is 15.72V and the charging current is 600mA

Test connection diagram:

TTC waveform:

Please help us confirm it,Thank you!

0 Michael Emanuel35 over 3 years ago in reply to user6555887

TI__Mastermind 40305 points

Hello,

The image indicates you have pulled TTC high. Pulling TTC high disables the safety timer. Leave JP1 floating to enable the safety timer.

Thanks,

Mike Emanuel

Please click "Resolved" if this answered your question.

0 user6555887 over 3 years ago in reply to Michael Emanuel35

Prodigy 230 points

Dear Mike:

Is it OK to connect the TTC pin to a capacitor to GND during circuit design? Is termination current enabled？Will the safety timer reset according to the conditions described in the specification?

Thank you very much!

Ellie

0 Michael Emanuel35 over 3 years ago in reply to user6555887

TI__Mastermind 40305 points

Dear Ellie,

The intended use of the TTC pin is to place a capacitor to enable a charge safety timer. If you wish to use the safety timer please remove JP1. As long as only the capacitor is present, and no pullup to VREF nor pulldown is present, termination will be enabled and the safety timer will be enabled (according to the capacitor selection equation with K_TTC and C_TTC).

Thanks,

Mike Emanuel

Please click "Resolved" if this answered your question.

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BQ24610: Fast charge safety timer