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TPS40425: Can TPS40425 or TPS40428 support two channel on-die voltage sensing?

Part Number: TPS40425
Other Parts Discussed in Thread: TPS40428, , TPS53681

i have a design for 1.2VA/15A and 1.2VB/15A, and both rails requires on-die voltage sense from ASIC. Can i use TPS40425 or TPS40428 for this?

Thanks.

  • Hello, 

    TPS40425/8 can support two outputs. 

    The channel 2 does not have remote sense amplifier, but it can sense Vout at load side (ASIC side). 

    Thanks

    Qian

  • Hi Qian,

    so that means the channel2 can't be used for on-die sensing, due to lack of diff amplifier, right?

    is there any controller (TPS40xxx) can support this request (both channel has diff amplifier for on-die sensing)?

    Thanks.

  • Hello, 

    Without diff amplifier, the Vout sense trace can still be connected to ASCI side, but the grounding offset between controller and ASIC can not be eliminated. 

    If the grounding offset is very small, let's say a few mV, then Vout at ASCI side is only a few mV off which may not be an problem for your system. 

    If you do need diff amplifier for both rails, TPS53681 is an option. 

    Thanks

    Qian

  • Hi Qian,

    Thanks.

    The "on-die sensing" here means the controller senses the voltage for feedback loop control from ASIC's dedicated Vsen/Vss pins, not directly Vout/GND nets.

    Without diff amplifier, will the on-die sensing work properly if connect ASIC Vsen/Vss pins directly to TPS40425/8's loop2 VSNS/GSNS? (assume no grounding offset). 

    Meanwhile i will look into TPS53681 as well.

    Thanks.

  • Hi Qian,

    Thanks.

    The "on-die sensing" here means the controller sense the voltage for feedback loop control from ASIC's dedicated Vsen/Vss pins, not directly Vout/GND nets.

    Without diff amplifier, will the on-die sensing work properly if connect ASIC's Vsen/Vss directly to TPS40425/8's loop2 VSNS/GSNS?

    Meanwhile i will look into TPS53681 as well.

    Thanks.

  • Hello,

    The VSNS and GSNS of ch2 is only for voltage sense for telemtry, not for control loop. 

    Without diff amplifier, ch2 can not sense the voltage between Vsen and Vss pins of ASCI.  

    We have to consider other device. 

    Thanks

    Qian