# Voltage Shift 0-5V to 0- (-300mV)?

Ive been hurting my brain a lot on this one and reading up on opamps, clamps, and level shifters, but still can't figure it out.

I need to take a 0v to 5v signal (TTL) and convert it to 0v to (negative) 300mV.

So far, I only could find this circuit which shifts this in reverse and meant for AC: https://www.maximintegrated.com/en/design/technical-documents/app-notes/4/4836.html

Id be super grateful for any help! :)

Edit: The reason I was adding the 2nd opamp was I wanted to use it as a simple NOT gate, since I have it to spare. Any tips how to do that with the split supply?

• Use an opamp with a gain of -0.0600. You will need a negative rail if you want a negative voltage. Commented Apr 5, 2022 at 3:18
• That’s an unusual requirement. Can you explain a bit more what it is for? Commented Apr 5, 2022 at 3:28
• Refer to the old Texas Instruments "TTL Data Book" for the details on TTL levels. Commented Apr 5, 2022 at 3:56
• Your question is missing important information. 1. What power supply voltages are available for this? 2. What is the longest possible time the signal will be in the -300 mV state? 3. Which input level (0 V or +5 V) is being translated to -300 mV? Commented Apr 5, 2022 at 4:23
• you can invert to -5 then scale down with R's . How much current? Use a suitable V+/V- supply. Commented Apr 5, 2022 at 4:24