Looking for a high Voltage Comparator single ended 40V with a latch

Thread Starter

MikeJacobs

Joined Dec 7, 2019
95
Looking for a high Voltage Comparator single ended 40V with a latch
Anyone have any recommendations?
Would have to be singled ended with a reference to ground.

I could probably built one from an op amp but was hoping to find an all inclusive part.

any help much appreciated

Thanks!
 

Thread Starter

MikeJacobs

Joined Dec 7, 2019
95
Not sure what you mean by single ended 40V. Supply voltage? Input voltage? What other voltages are available for the latch? What determines when it unlatches?
Single ended as in not differential. As in 40V with respect to ground, that would be the input voltage. Supply voltage im flexible on something 15V or less. I would like a manual reset on the latch. a pin that would have to be pulsed high to reset.
Similar to an SR latch.
Like I said, I could make one but hoping to not have to.
 

dl324

Joined Mar 30, 2015
9,577
Single ended as in not differential. As in 40V with respect to ground, that would be the input voltage.
You can use a voltage divider on the input.
Supply voltage im flexible on something 15V or less. I would like a manual reset on the latch. a pin that would have to be pulsed high to reset.
Similar to an SR latch.
Like I said, I could make one but hoping to not have to.
https://www.ebay.com/itm/192830178485
 

KMoffett

Joined Dec 19, 2007
2,784
"As in 40V with respect to ground, that would be the input voltage " What does that mean? Do they want to change the output if the input is either +40V or ground? Like a 40V logic gate? How close to +40 or 0V to change the output? Or are there only two possible input levels: +40V and 0V?
 

ronsimpson

Joined Oct 7, 2019
400
There is a 15V supply to power the parts.
When the "40V" supply gets above 40 you want the output to latch high, (hold) until it is manually reset. (question mark)

Voltage comparator with reference. In this case there is a 1.24V reference. The 40V will need to be divided down by two external resistors to make 40=1.24. Most comparators do not have a reference internal. Most have a output that only pulls down while this one the output pulls up or down. Maybe the 15V is good and stable and we can compare 40/x to 15V. But if the 15 is not accurate then another reference is needed.
1577737487548.png

This next part is close to what you need. Inputs 1,3 set the flip flop H or L. One side can look at 40V divided down and the other input will look at a reset switch/button.
1577737757159.png
There are several members of the MCI841 family. Pin 3 and 1 can connect to (+) or (-) depending on what part you pick.

All these parts are built to run from a 1.5 to 5.5V supply! I have used these parts and found them to be very handy.
 
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