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Can AD7655 really sample at 1 MSPS?

Question asked by ezmbi on Sep 22, 2016
Latest reply on Sep 22, 2016 by Gnib

The AD7655 data sheet (Rev. D) states that the ADC is capable of 1 MSPS (normal mode). That's in the features caption and in Table 1 on page 1. However, table 3 on page 6 specifies the "time between conversions" t_2 to be greater than 2 us. How come this converter can sample at 1 us, then? I reckon, either must be true: which one?

 

I'd like to know because we would like to replace an AD7654 (specified at 500kSPS) with a faster dual-channel ADC. The AD7655 would be an ideal candidate because it is pin-compatible and it'd allow us to test the behaviour on the same board.

 

If the AD7655 cannot sample (or cannot be made to sample) at 1 MSPS after all and the datasheet proves to be wrong, could anybody suggest a replacement for it that meets the critera:

- pin-compatibility with AD7654

- two-channel simulatneous

- sample rate > 1 MSPS

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