AD7903 - can it do +/-5v differential input?

Hello Rodney,

the AD7903 can work with negative differential input voltages, +/-5V for the differential input voltage (IN+ - IN-) would not be a problem. But it can not work with an absolute voltage below 0V at its analog inputs.

In your description the individual input pins would go down to -5V. According to the datasheet the absolute input voltage at IN+ and IN- must be in the range -0.1V to Vref+0.1V.

best regards

Achim

Hi RodneyDavies ,

 Achim is correct. The absolute input voltage, INx+ and INx-, is -0.1V to Vref+0.1V. You will need to condition your -5V input to a voltage level acceptable by the ADC. Connecting the -5V input directly should be avoided as it may damage the device.

Regards,

JC

Hi RodneyDavies ,

 Achim is correct. The absolute input voltage, INx+ and INx-, is -0.1V to Vref+0.1V. You will need to condition your -5V input to a voltage level acceptable by the ADC. Connecting the -5V input directly should be avoided as it may damage the device.

Regards,

JC

Thanks JC and Achim - I will need to use appropriate conditioning drivers for this.