• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 441 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

PGA280 Output help

Manjunath Bhat
Prodigy 120 points
Other Parts Discussed in Thread: PGA280

Hi All,

I am planning to measure -ve and +ve voltage on my board using PGA280 amplifier.

If I use VSP=+15V , VSN=-15v, VSOP=5V and VSON=0V( GND) ( Fig 43 in PGA280 datasheet)

and G=1 what would be the differential output voltage range for the following inputs.

Vin = +10V , 5V , 0V , -5v , -10V.

what would be the range for VOP and VON for all the above input , if I use VSOP=5v. and output signal rate ?

from the data sheet , its not clear on diffrential output range of the device.

Can I interface PGA280 out to an ADC with diffrential input capability with signal range of 3.3v ?

please help.

thanks.

 

  • 0
    TI__Guru 55466 points

    Hello Majunath,

    The differential output stage voltage swing is specified to be 100mV from the rail (VSOPand VSON supplies)   with a load current of 2mA.  The VSOP - VSON output voltage supplies are specified to operate from 2.7V to 5.5V.  The device may be used with  an ADC with a signal range of 3.3V by setting VSOP=+3.3V and VSON=GND.  The VOCM is normally biased at a voltage of (VSOP-VSON)/2 .

    The differential output voltage is limited by the VSOP and VSON output supplies.  If you operate the device with  VSOP-VSON=5V; the maximum allowed output differential signal will be about ~4.8V. 

    If you use the device with a Gain = 1; the maximum allowed differential signal that you will be able to input will be around ~4.8V; if you exceed this input voltage with Gain=1; you will overload the amplifier.  

    The device is very flexible and offers input gain settings from1/8 V/V to 256V/V in binary steps.  For example, if you require an input differential signal of 8V; you could set the device to use gain of 1/2 to obtain a differential output signal of 4V

    Best Regards,

    Luis