DRV425-Q1: Use of an external reference for multiple DRV425-Q1 devices

Frank Meyer

Part Number: DRV425-Q1

Hello,

If an external reference were to be used to drive the DRV425-Q1's REFINT (pin 5) when the device is operated at 5 VDC, what is the max/typical input current that can be expected? It feeds the return leg of the DRV425-Q1's differential amplifier.

The data sheet doesn't specify this in section 6.5 under voltage reference or Shunt-sense Amplifier.

Thanks in advance.

over 5 years ago

0 Javier Contreras4 over 5 years ago

TI__Mastermind 31040 points

Frank,

I will look at this closely tomorrow and let you know.

0 Javier Contreras4 over 5 years ago in reply to Javier Contreras4

TI__Mastermind 31040 points

Frank,

The load will be a 40K Ω as you see on the input. So the largest current drop will either be (VS - Vref)/40K or (Vref-GND)/40K which every is larger. Also since the input voltage will differ you will need to understand the load will change. So a buffer would be required. If you are sharing more than two Vref for pins you may wnat to use a buffer.

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DRV425-Q1: Use of an external reference for multiple DRV425-Q1 devices