BQ76942: OTP Programming, Powering and charge pump

Janardhanbabu Marri

Prodigy 125 points

Part Number: BQ76942

Tool/software:

Hi Ti team,

I have some droughts regarding turn on the chip and charge pump

Can I turn on the BQ76942 chip by providing 12V using bench-top (without cell voltages) across the BAT and VSS pins and also pull down the TS2 (for wake-up) and RST_SHUT?
Can I OTP the chip without connecting cell voltages or without a battery?
How does the charge pump circuit work? (Datasheet tells only about configuration of adding BAT voltage + 11V or 5.5V)
Is there any block internal diagram for the charge pump?

Regards,

Janardhan Babu M.

over 1 year ago

0 Thomas Rainey over 1 year ago

TI__Expert 4320 points

Hi Janardhan,

1. For OTP, 12 V must be applied to the BAT pin and the highest VCx pin (VC10 for the BQ76942). As for TS2 the device should wake up when a voltage is applied to the BAT pin. RST_SHUT can be connected to VSS. You can refer to this FAQ for helpful information on OTP.

2. Yes, you are able to OTP without cell voltages or a battery as long as you meet the requirements stated above.

3. For a better understanding of how the charge pump works, I would recommend reading section 4 Charge Pump (and FET Turn On) of the Multiple FETs with the BQ76952, BQ76942 Battery Monitors (Rev. A)

4. Yes, you can refer to the Pin Equivalent Diagrams for the BQ76952, BQ76942, and BQ769142 application note. Specifically Figure 1-2. CHG Pin Equivalent Diagram, Figure 1-3. BAT and CP1 Pin Equivalent Diagram, and Figure 1-4. DSG Pin Equivalent Diagram.

Best regards,

Thomas Rainey

0 Janardhanbabu Marri over 1 year ago in reply to Thomas Rainey

Prodigy 125 points

Hi Thomas,

Thanks for the fast replay, regarding Charge pump i have gone through the references in the above message. But i am trying to simulate the charge pump circuit to know more about it. Can you help me about sharing some more details about charge pump circuit.

Regards,

Janardhan babu Marri

0 Thomas Rainey over 1 year ago in reply to Janardhanbabu Marri

TI__Expert 4320 points

Hi Janardhan,

Unfortunately I am unable to share more details on the charge pump circuitry, due to it being proprietary information.

Best regards,

Thomas Rainey

+1 Janardhanbabu Marri over 1 year ago in reply to Thomas Rainey

Prodigy 125 points

Hi Thomas,

Not an issue, thanks for your support.

have a great day.

Regards,

Janardhan babu Marri

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BQ76942: OTP Programming, Powering and charge pump