need simple sample and hold chip

Apr 06, 2007 5 Replies

I'm looking for the switch or gate for a sample and hold. requirements: +/- 5V input , TTL control referenced to analog ground, dip or soic package. 4066 or 4053 need not apply. bandwidth is 20 khz and sampling rate is undersampling,ie 100 to 500 hz.



any candidates?



thanks, Steve Roberts



One possibility is a programmable-current (transconductance) op amp. LM13700 has two sections, first section can be the follower, second can be the buffer, stick a capacitor in between (or onto the buffer negative feedback) and just gate the program current on the follower to HOLD.

Integrated solutions include LF398 (but it seems like overkill here).

Why not 4066 or HC version?

John

Maxim has appnote 638, showing specs of analog switches. Lots of them are for +/- supply with separate logic ground.

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Selecting the Right CMOS Analog Switch - Maxim/Dallas

-- John

The DG411/412/413 are ok parts. You didn't state why you can't use the 405x parts.

The DGxxx parts are analog switches they started out IIRC as Siliconix parts. Today many people make them. If you google on: DG411 Datasheet You are likely to find the makers. Vishay would be the most likely source today. IIRC Maxim has published a datasheet for them so they may also make them.

LF398 ?

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

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