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BQ40Z80: BQ40Z80 abnormal behavior in the product line

Part Number: BQ40Z80


The customer have a project using BQ40Z80 for 7-series, but there has always been a problem in their production line, which triggered the anti-cracking mechanism of the IC and required re-burning the software. Therefore, they wanted to understand the following three questions:
1. According to previous communication records, the anti-cracking of IC is judged by the voltage of TS1. Could you please explain the logic of anti-cracking in detail? How much greater is the voltage? How long does it last? At which stage the judgment was cracked.
2. They found that when they equip the battery cell, the IC will be activated by mistake. Generally, when the third cell is applied, the IC is activated. Will the activation of the IC during this power-on process cause the IC Flash to be erased?
3. They found that every time the IC is activated, TS1 will have an abnormal spike, as shown in the figure below, what is the reason for the spike?

  • Hello Fabio,

    1- I do not understand what you mean by "anti-cracking". Please elaborate.

    2- What do you mean the by IC is activated by mistake? Is the device waking up? Turning on and off the device does not erase the flash. 

    3- It could be due to the startup transients. They can add a capacitor in parallel with the resistor for immunity. Also, where is the GND of the IC connected to? Please share the schematic.

    Does equip the battery cell mean attaching the batteries to the gauge? Plugging batteries can cause high transients. There are some GND guideline we have for this. I can elaborate more when I see the schematic. 

    Regards,
    Jose Couso