ADS1675: Best driver for positive, single-ended input

Andrea Fontana

Part Number: ADS1675
Other Parts Discussed in Thread: THS4503, THS4501, THS4541

Hello,

I have an application for which i need a very precision ADC to sample a signal which frequencies range from DC to (raughly) 350KHz and i'm thinking to use sigma-delta ADS1675.

Keep in mind that the input signal is positive-only (respect to ground).

Looking to the datasheet i've seen that a THS4503 is used to drive the ADS1675, but the "strange" supply levels (+9V / -4V) are quite boring to be built and provided to the driver.

Due to the fact that my signal is DC and positive-only, i'm wondering if i make a mistake using a THS4501 in single supply (+5V / GND) with a common mode reference of 2.5V.

In attach you may found the TINA schematic....

For the example i've used a positive signal sin @ 100KHz.

Thanks in advance for your reply.

Best Regards

Andrea

Driving_ADS1675.TSC

over 8 years ago

0 Ryan Andrews over 8 years ago

TI__Guru 69476 points

Hello Andrea,

Thank you for your post and welcome to our forum!

The ADS1675 datasheet has not been updated in a few years. The THS4503 can still work fine in the circuit configuration you proposed, but perhaps you might also consider something newer like the THS4541 (see comparison below). This device has almost twice the bandwidth and less than half the broadband voltage noise. The newer THS45xx FDAs in this device family are commonly used to drive our wide bandwidth, unbuffered delta-sigma ADCs.