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BQ25703A: bq25703A / Maximum input current during PFM mode

S.Satoshi
Guru 21685 points
Part Number: BQ25703A

Hi,

Now my customer consider to bq25703A and they are investigating the detail of input current during PFM mode. They need to investigate it because they need to meet their system to California Energy Commission. So please discuss if you can prepare any information about maximum (worst) value of IAC_SW_LIGHT_buck, IAC_SW_LIGHT_boost and IAC_SW_LIGHT_buckboost.

This is request from our major customer so please let me discuss off like if you can.

Best Regards,

Satoshi / Japan Disty

  • 0
    TI__Guru 56650 points
    The PFM to PWM transition current is around 0.5A inductor average current in different mode. It is also related to external ACP/ACN pin filter parameter because in buck mode, the inductor current estimation is related to the peak sensing current. So, overall, the maximum PFM to PWM transition current is from couple hundreds mA to 1.xA.
    To meet energy star, the light load power is around 250mW. That current is much less than 100mA. So, bq25703A's PFM cover all buck, buckboost and boost mode energy star request.
  • 0 in reply to Wang5577
    Guru 21685 points
    Hi Wang,

    Now their target total system power is less than 120mW at 12V VBUS. So I'd like to have any information like simulation data about leakage current and/or efficiency (total power loss) at no load operation. Customer requests this information for competitor also.
    I can inform you the detail of this business off line. Please refer my profile for my contact info.

    Best Regards,
    Satoshi
  • 0 in reply to S.Satoshi
    TI__Guru 56650 points
    For 120mW power, bq2570x charger works on PFM.
    For notebook charger, the system standby power consumption is about 200mW. Energy star requests input power less than 500mW which include adapter power loss. Assume adapter side 50% efficiency. Charger side need to have 80% efficiency at 200mW.
    If their total system standby power is less than 120mW, charger and adapter can be easily to meeting energy star.

    Please let me know if you see a new energy star requirement.