Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Jeroen Belleman <jeroen@nospam.please>
Newsgroups: sci.electronics.design
Subject: Re: AD5791
Date: Tue, 4 Jun 2024 21:53:13 +0200
Organization: A noiseless patient Spider
Lines: 15
Message-ID: <v3nr7c$ibi4$1@dont-email.me>
References: <vqcu5j9nu9tf051iu0f1grobcehg1pb0rv@4ax.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 04 Jun 2024 21:51:08 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="3d816770846643475677dc42d4d380d3";
	logging-data="601668"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18IZzL6vMjjlb+17tIwadyk"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Cancel-Lock: sha1:XotLzX/Zk8jdqSG4J7wxA5daTuw=
Content-Language: en-US
In-Reply-To: <vqcu5j9nu9tf051iu0f1grobcehg1pb0rv@4ax.com>
Bytes: 1541

On 6/4/24 19:48, john larkin wrote:
> https://www.analog.com/en/products/ad5791.html
> 
> That's an amazing part. 20 bit DAC with 1 PPM accuracy and 0.05 PPM
> per degree C tempco.
> 
> My main gripe is its 3.4K output impedance, which makes a lot of
> Johnson noise. I suppose I could run a bunch in parallel.
> 

But you can power the chip from +/-16V and the LSB can be in
the 25uV ballpark. The Johnson noise of 7.5nV/rtHz doesn't
seem so bad then, does it?

Jeroen Belleman