THS3095: THS3095 Asymmetric Supply

Magyar Andras Tamas

Intellectual 400 points

Part Number: THS3095
Other Parts Discussed in Thread: THS3491

Hi,

Is it possible to supply the THS3095 with for example +20V/-5V asymmetrically?

Thanks,

Andras

over 3 years ago

0 kai klaas69 over 3 years ago

Guru 140200 points

Hi Andras,

yes you can. But don't violate the absolute maximum ratings, especially referring to the input voltages.

Kai

0 Magyar Andras Tamas over 3 years ago in reply to kai klaas69

Intellectual 400 points

Hi,

Of course thanks. I am driving a mosfet with this amplifier to convert it to current and when I change it to asymmetric supply (+18V/-5V), in the simulation Vgs voltage - that is the output of the amplifier and the input of the gate - starts from 1.7V not from 0V which gives me a surprisingly good result reading the current (I(Rsense).

Do you know when this effect is? Please below see the photo with the symmetric supply (+/-15V), where Vgs start from 0V and the output has some glitch.

0 Michael Steffes over 3 years ago

Guru 47005 points

Sure Magyar,

You also need to observe the I/O headroom limits and consider the disable pin and reference pin operations. There is an upgrade to this device in the THS3491,

This I/O headroom stuff comes up so much, those were the first couple of articles in the signal sped up series I am doing,

https://www.planetanalog.com/input-and-output-voltage-range-issues-for-high-speed-amplifiers-insight-1/

https://www.planetanalog.com/input-and-output-voltage-range-issues-for-high-speed-cfas-and-fdas-insight-2/

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THS3095: THS3095 Asymmetric Supply