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TLV4H390-SEP: Common mode input range of TLV4H390-SEP

Adam Gilbert
Prodigy 130 points

Part Number: TLV4H390-SEP
Other Parts Discussed in Thread: TLV4H290-SEP, TLV9024

Hello, I'm interested in powering the TLV4H390-SEP with 1.8V(V+) and 0V (V-)

In the data sheet  www.ti.com/.../tlv4h390-sep.pdf, the common mode input range is listed as (V-)-0.2 to (V+)-1.5. Could you confirm that this actually means that the common mode range would be -0.2V up to 0.3V?

I can see on other forum posts for this part that a possible commercial equivalent is www.ti.com/.../tlv9024.pdfThis part seems to have a common mode input range of (V-)-0.2 to (V+)+0.2  - so I believe this would give me -0.2V to 2V. 

Does the TLV4h390 data sheet have a typo? 

I plan on using this part as part of an over current detection circuit so likely I'll just bias one input at a reference level and the other pin would be proportional to the current I'm measuring. Mostly want to figure out what level to bias one of the comparator input pins at. Half supply (0.9V) would probably be my start point. The data sheet however seems to hint that I'd need to bias at 0.2V maybe.

On a slightly different topic if I were to use the TLV4H290-SEP isntead, I could power at 3.3V or 5V. Which I guess would greatly increase the common-mode range. Would the part be happy having a pull up on its open drain outputs to 1.8V? Can the propagation speed of the TLV4H290 be improved by using stronger pull ups e.g 1k?

Appreciate the help!

Adam

 

  • 0
    TI__Guru 68676 points

    Hi Adam,

    Yes, the TLV9024 is the commercial version.

    Yes, the input range would be 0.3V max at 1.8V. Not a typo..sorry..

    In characterization, it was seen that the offset changed more than we wanted in the "upper" input pair after extended testing, so we limited the input to VCC-1.5.

    Yes, it is still rail to rail under the hood, but we do not guarantee the upper common mode range. Officially, TI cannot condone exceeding the specifications...but...your choice.

    Yes. You can pull the output up to any voltage up to 6V, regardless of supply voltage. Decreasing the pull-up resistor value will speed up the risetime, but at the expense of power dissipation and VOL.

  • 0 in reply to Paul Grohe
    Prodigy 130 points

    Thank you for the quick reply! From your info I think I should use the TLV4H290-SEP. I can then run it at a higher voltage and still interface with the 1.8V logic on our FPGA. Cheers!