AFE5807 - question about integrated ADC

Damian Cacko

Other Parts Discussed in Thread: AFE5807, AFE5808A

Hi,

I've got a little problem with AFE5807.
I found it difficult to determine, whether it has 12 or 14-bit ADC.
In description of AFE5807 on TI website there is 12 bit, but
underneath in the AFE's comparison table there is "12, 14-bit".
Same situation in datasheet - first page - 12-Bit, 80 MSPS.
OK, but on "Theory of Operation/ Analog to digital converter" pages I found that there are 14bit ADCs for each channel,
what is more, there is another information suggesting 14 bit resolution: page 31, register map, adress 4[2:0].

I must be certain. So what is (maximum) the resolution finally?

Second question: are there any specialized powering solutions suggested for AFEs?

Regards,

Damian C.

over 11 years ago

0 Chuck Smyth over 11 years ago

TI__Expert 6320 points

Damian,

The AFE5807 and AFE5808A both have a maximum Resolution of 14-bit. However, the AFE5807 is a lower-power version of the AFE and it defaults to 12-bit mode by truncating the 2LSBs. You may also see 16-bit mode, but this means the ADC only adds two zeros for two LSBs in order to provide a convenient data format. See pg. 27

Thanks,

Chuck Smyth

0 Zubair Lutfullah over 11 years ago in reply to Chuck Smyth

Intellectual 295 points

Can you clarify a bit about the Samples per second for each bit resolution?

Are we limited to 12bit 80SPS or 14bit 65SPS?

Is 14bit 80SPS available?

Thanks

Zubair

p.s. I'm open to any other IC if you have suggestions. Max bit resolution + Max Sampling frequency.. For ultrasounds..

0 Chuck Smyth over 11 years ago in reply to Zubair Lutfullah

TI__Expert 6320 points

Zubair,

14bit/80MSPS is not available. For 80MSPS, you must use 12bit mode.

Thanks,

Chuck Smyth

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AFE5807 - question about integrated ADC