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Electronics => Projects, Designs, and Technical Stuff => Topic started by: F1GWR on August 14, 2024, 08:56:54 am

Title: LTC2928: what is the trick to allow *four negative* voltage monitoring?
Post by: F1GWR on August 14, 2024, 08:56:54 am

Hi,

I saw an example of one LTC2928 (among three) used in the Agilent DSO9404A to monitor four negative voltages. Schematic is not available.

The question is not "would this be possible?", because it is, but "which application circuit using this LTC2928 would be able to monitor four negative voltages?" As this IC was initially designed solely for four positive or one negative and three positive depending on the VSEL tying.

Checked datasheet, app notes and design notes but didn't find any clue...

Any help appreciated.

Title: Re: LTC2928: what is the trick to allow *four negative* voltage monitoring?
Post by: Andree Henkel on August 14, 2024, 11:26:37 am

look to the left: OP484, likely 3 of the four channels of it do it.

Title: Re: LTC2928: what is the trick to allow *four negative* voltage monitoring?
Post by: F1GWR on August 21, 2024, 08:25:42 am

Quote from: Andree Henkel on August 14, 2024, 11:26:37 am

look to the left: OP484, likely 3 of the four channels of it do it.

Hi Andree,
Thanks. Sorry for late answer, just saw your message.
Yeah you may be right obviously! This fourfold opamp should be wired as an inverting amplifier with gain -1. I'll check that when I will have some time after urgent tasks...
Will let you know.
Christian