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Query on DVDD of TPA2051D3

Sateesh Nayak
Prodigy 110 points
Other Parts Discussed in Thread: TPA2051D3

Hi,

Please suggest for the below queries related to TPA2051D3.

1) According to TPA2051D3 datasheet the delay tpws should be less than 100us.

In our case AVDD is connected to Battery voltage. Consider following cases

case (i) if AVDD is > 3.3V, DVDD will be always present and within time tpws .
 case ii) If AVDD is < 3.3V, DVDD will be off  but AVDD will be on (<3.3V) so the only way that DVDD can get on is through charging and once the charger is connected we will get DVDD within tpws  so the question is  whether digital part will work as the delay was lesser than  tpws or it doesn't work since AVDD is always on.

2) We can use different voltage for I2C and DVDD according to datasheet.



Lets say I am using DVDD = 2V for TPA2051D3 and the SCL, SDA lines are pulled to 3.3V
which is a valid case as Vih for 3.3 is 3V and DVDD is less than 3V for PVDD = 3.7V.
So on what voltage level does enable work ? Is it 3.3V like the SDA/SCL lines or we should consider DVDD as 2V for Enable.

3) Datasheet says Recommended voltage for DVDD is 1.7 to 3.3. Can the digital part be 
still on for 1.2V as it doesn't cross absolute minimum volatge. Does that twps timing rule holds good when DVDD is 1.2V or the DIgital part will be off below 1.7V.

Regards,
Sateesh

  • 0
    TI__Mastermind 37045 points

    Hi, Sateesh,

    Sorry we missed this post. Is this still open?

    My colleague will get back to you on this.

    reg,

    Paul.

  • 0 in reply to user5276421
    Prodigy 110 points

    Hi Paul,

                 Its still open. I need clarifications for above queries.

    Regards,

    Sateesh

  • 0
    TI__Mastermind 34665 points

    Hi Sateesh,

    Looks like you're trying violate our device spec conditions. I will provide guidance, but we only gaurantee our datasheet specs.

    1. For the Tpws violation of 100us with AVDD and DVDD, I would recommend ensuring EN pin goes low before or when DVDD turns off and AVDD is <3.3V. Once the charger is plugged in and DVDD is available wait the min 1000us before EN goes high.
    2. Separate or different voltages for DVDD and I2C pull-up isn't recommended. When DVDD isn't available I2C communication isn't available for TPA2051D3. The I2C input buffers are bias by DVDD and driving the I2C pins above DVDD will turn the ESD protection diodes to clamp the voltage to DVDD + diode voltage. The EN is also works of DVDD like the SCL/SDA pins.
    3. Below 1.7V the digial doesn't work. The absolute min voltage isn't for device operation. Is the absolute min recommended voltage prevent device damage.