Looking for a cheap >800ksps 16-bit D/A

[SioL]

Hi there,

I'm looking for a cheap D/A, needs to do at least 800ksps at 16 bits.
More speed or better accuracy would be welcome, but I'm not prepared
to pay an arm and a leg for that bonus.

From what I see so far prices go crazy at such speeds and resolution.

SioL

 

[[email protected]]

Hi there,

I'm looking for a cheap D/A, needs to do at least 800ksps at 16 bits.
More speed or better accuracy would be welcome, but I'm not prepared
to pay an arm and a leg for that bonus.

From what I see so far prices go crazy at such speeds and resolution.

Depends what you mean by crazy

http://focus.ti.com/lit/ds/symlink/ads8371.pdf

is claimed to be $12 for 1k quantities, offering 750k sample/sec. for
$12.66 you can go up to 1.25M samples/sec with the

http://focus.ti.com/lit/ds/symlink/ads8401.pdf

The Analog Devices part

http://www.analog.com/UploadedFiles/Data_Sheets/3409832066141394038AD7725_a.pdf

is $20 in 100-up qunatities, but it is sigma-delta.

http://www.analog.com/UploadedFiles/Data_Sheets/297966481931038630530425AD7653_a.pdf

is SAR, but only costs $12.72 100-up.

 

[SioL]

Depends what you mean by crazy

http://focus.ti.com/lit/ds/symlink/ads8371.pdf

is claimed to be $12 for 1k quantities, offering 750k sample/sec. for
$12.66 you can go up to 1.25M samples/sec with the

http://focus.ti.com/lit/ds/symlink/ads8401.pdf

The Analog Devices part
...

Bill, I need a D/A. You listed A/D converters only.

SioL

 

[[email protected]]

Hi there,

I'm looking for a cheap D/A, needs to do at least 800ksps at 16 bits.
More speed or better accuracy would be welcome, but I'm not prepared
to pay an arm and a leg for that bonus.

From what I see so far prices go crazy at such speeds and resolution.

SioL

If you want cheap then you dont need 16 bits. It's very unlikely you
need 16 bits anyway and even more unlikely you'll get it even if you
were prepared to pay. 12 bits is the realistic limit for low cost
options.

 

[Spehro Pefhany]

Hi there,

I'm looking for a cheap D/A, needs to do at least 800ksps at 16 bits.
More speed or better accuracy would be welcome, but I'm not prepared
to pay an arm and a leg for that bonus.

From what I see so far prices go crazy at such speeds and resolution.

SioL

Some of the audio ones come close to your stated requirements.


Best regards,
Spehro Pefhany

 

[John Larkin]

Hi there,

I'm looking for a cheap D/A, needs to do at least 800ksps at 16 bits.
More speed or better accuracy would be welcome, but I'm not prepared
to pay an arm and a leg for that bonus.

From what I see so far prices go crazy at such speeds and resolution.

SioL

TI's DAC8541 is about $3 in quantity. Ole reliable PCM56 is cheap,
bipolar, internal ref, available in DIP, and is actually pretty good
at DC.

Both serial, of course.

John

 

[[email protected]]

Bill, I need a D/A. You listed A/D converters only.

Oops. A senile moment ... meanwhile, how is this for $16 in small
quantities (from Digikey)

http://focus.ti.com/lit/ds/symlink/dac8830.pdf

Analog Devices have a couple of comparable parts

http://www.analog.com/UploadedFiles/Data_Sheets/52988073AD5541_5542.pdf

http://www.analog.com/en/prod/0,,AD5545,00.html

at comparable prioces.

 

[Joerg]

Hello Spehro,

Some of the audio ones come close to your stated requirements.

SioL might consider using these in staggered fashion to achieve the
required sample rate. I did this a lot with ADCs.

 

[SioL]

TI's DAC8541 is about $3 in quantity. Ole reliable PCM56 is cheap,
bipolar, internal ref, available in DIP, and is actually pretty good
at DC.

DAC8541 is way too slow, at 10uS settling time. PCM56 is much better at 1.5uS,
but still too slow for 800ksps.

Both serial, of course.

That's what I'm looking for

SioL

 

[SioL]

Hello Spehro,


SioL might consider using these in staggered fashion to achieve the required sample rate. I did this a lot with ADCs.

Hmm, using another D/A to provide ref. voltage for the first D/A?

SioL

 

[SioL]

Oops. A senile moment ... meanwhile, how is this for $16 in small
quantities (from Digikey)

It happens

http://www.analog.com/en/prod/0,,AD5545,00.html

This one looks good. I thought there might be something cheaper out there.
I guess I'll have to adjust my target price a bit higher.

Help appreciated!

SioL

 

[Joerg]

Hello SioL,

Hmm, using another D/A to provide ref. voltage for the first D/A?

That won't likely become accurate enough. I was thinking of using
several slower audio DACs and then having them feed an output node in a
round robin fashion through a "chopper". I usually had to do this the
other way around, using ADCs that were too slow for the application and
then ganging several. This is much more difficult than DAC ganging
because I had to auto-align gain, offset and clock phase. The latter is
the tough one but in your DAC application you might not have to worry
much about it.

 

[SioL]

That won't likely become accurate enough. I was thinking of using several slower audio DACs and then having them feed an output
node in a round robin fashion through a "chopper". I usually had to do this the other way around, using ADCs that were too slow
for the application and then ganging several. This is much more difficult than DAC ganging because I had to auto-align gain,
offset and clock phase. The latter is the tough one but in your DAC application you might not have to worry much about it.

Hey, thanks, that's an interesting idea indeed, could save ~4-5 US$
I'll see how I fare with PCB real estate.

SioL