Tool/software:
Hi TI Team,
I am encountering an issue with the BQ24073 Li-ion battery management IC when trying to reset an active PCM (Protection Circuit Module) on a Li-ion battery. Here are the observations:
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Setup Details:
- The PCM activates due to low battery voltage (below 3V) and disables the battery output (0V).
- During power-up, I observe a transient voltage rise from 0V to 3.5V on the BAT and BAT1 pins for ~200ms.
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Current Measurement:
- Using a 10Ω resistor in series with the battery, I measured:
- 156mV drop (15.6mA) for 28ms.
- 662mV drop (66.2mA) for 25ms.
- Using a 10Ω resistor in series with the battery, I measured:
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Additional Observation:
- When I connect the battery directly to a bench power supply at 3V, the PCM wakes up, and the battery output is restored. This confirms that the battery and PCM are functioning correctly.
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Issue:
- Despite the transient voltage rise from the BQ24073, the PCM remains in its locked state, and the battery output stays at 0V.
- The BQ24073 seems unable to reliably trigger the PCM to reset and restore the battery's normal operation.
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Questions:
- What are the best practices to configure the BQ24073 for triggering PCM reset, especially for transient scenarios?
- Are there specific considerations for timing, voltage, or current to ensure the PCM is reset properly?
- Could any additional circuitry (e.g., pre-charge or capacitor adjustments) help sustain the transient and meet the PCM's requirements?
- Are there any known limitations of the BQ24073 in handling PCM reset functionality?
I have attached oscilloscope screenshots showing the voltage and current behaviour during the event.
Thank you in advance for your support!