Hi,
I am in need of a micropower comparator with latch output.Application is surge monitor.Also i would like to know whether the comparator will be able to detect the short duration input pulse(i.e 2V signal of 20 micro second). Normally my input signal will be in the order of few millivolts. When surge occurs ,my voltage will go upto 2 Volts but only for a while(20 microseconds). Also the circuit should consume only few microamps(1-3 micro amps)
Suggest me an IC which suits my application.
Hello Sundari,
Your post originated in another E2E forum and was eventually transferred to ours over several days. I apologize for the delayed response.
It doesn't appear that TI has a micro-power comparator that includes the latch function you describe. I suspect you are going to have to use a micro-power comparator and follow it with a separate latch function to capture the 20 us pulse response from the comparator output. The TLV3491 nano-power comparator has a typical supply current requirement of 800 nA and is fast enough for your application.
It appears that you could satisfy the latch function using a flip-flop function, but again your very low current requirement limits the possibilities. TI has the very low current AUP logic family. It includes a positive-edge-triggered, D-type flip-flop with clear and preset functions - the SN74AUP1G74. Its static current is on the order of 900 nA. I suspect there is a set-up condition that would allow you to detect and hold the comparator output state required by the application. There may be other devices that could satisfy the "latch" function.
The combination of these two components should keep you well within your operating current budget.
Regards, Thomas
PA - Linear Applications Engineering