AFE58JD18: Differential Input Signal for AFE58JD18

Dmitri Gurevich

Part Number: AFE58JD18
Other Parts Discussed in Thread: AFE58JD16, PGA5807, AFE58JD32, ADS5294, ADS52J65, ADS52J91

Hi,

I have a differential ADC driver in my front-end. Can I connect the LNA of AFE58JD18 differentially, instead of the single-ended connection recommended in datasheet? And use both INP and INN analog inputs ?

Thanks

over 2 years ago

0 Karthik Nagabhushana over 2 years ago

TI__Expert 4690 points

Hi Dmitri,

AFE58JD18 can not support differential input. Among TI's Ultrasound AFEs, PGA5807 (8-channel analog out), AFE58JD16 (16-channel digital out), and AFE58JD32 (32-channel digital out) can support differential input.

Alternatively, since you mentioned that you already have a front-end, if all you require is a multi-channel ADC, you can refer to ADS52J91 (16/32 channel, 12-bit, 100/50 MSPS) or ADS5294 (8-channel, 14-bit, 80MSPS) or ADS52J65 (8-channel, 16-bit, 125 MSPS).

Let me know if you have any other questions. If not, consider closing this thread from your end.

Thanks,

Karthik

0 Dmitri Gurevich over 2 years ago in reply to Karthik Nagabhushana

Prodigy 10 points

Thanks Karthik

So if the AFE58JD18 was designed to work with a single-ended input, why does it have a negative input INM ?

0 Karthik Nagabhushana over 2 years ago in reply to Dmitri Gurevich

TI__Expert 4690 points

Hi Dmitri,

The AFE58JD18 input network is not symmetric for INP and INM as shown below -

INMx input takes the DC offset-correction input which cannot be disabled. Hence the AFE input must be given at INPx.

If that answered your question, consider closing this thread.

Thanks,

Karthik

0 Dmitri Gurevich over 2 years ago in reply to Karthik Nagabhushana

Prodigy 10 points

Thanks Karthik!

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AFE58JD18: Differential Input Signal for AFE58JD18