SN74LVC1G80-Q1: Feasibility of using with momentary contact switch in dome lighting application

Scarlett Cao

Part Number: SN74LVC1G80-Q1
Other Parts Discussed in Thread: SN74HCS72-Q1

Hi team,

May I have your suggestion on whether SN74LVC1G80-Q1 or any other logic device can help achieve the function below?

My customer is working on a dome lighting solution. Their application requirement is that the LED can be toggled between IN and OUT condition with momentary contact switch. Their current solution is IS32LT3175, a LED driver with integrated debounce and latch circuit on EN pin to achieve this. We do not have led driver product with same feature, so I'd like to propose replacement solution with a logic device before our LED driver product.

Could you check the following description about competitor's EN pin operation logic and suggests any way to work around? Thanks a lot

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 244390 points

This requires a pull-up resistor for the switch, an R-C low-pass filter for debouncing, an R-C circuit (or a reset IC) to generate a pulse to reset the state at power up, and a flip-flop with a negative-edge trigger and with Schmitt-trigger inputs, i.e., the SN74HCS72-Q1.

0 Dylan Hubbard over 3 years ago in reply to Clemens Ladisch

TI__Mastermind 42670 points

Hey Scarlett,

As Clemens suggested, the SN74HCS72-Q1 might be the best option to use here. Here is also a training video that I think provides similar functionality desired: https://training.ti.com/convert-momentary-switch-toggle-switch.

0 Scarlett Cao over 3 years ago in reply to Clemens Ladisch

TI__Expert 3410 points

Thanks for your reply Clemens :)

0 Scarlett Cao over 3 years ago in reply to Dylan Hubbard

TI__Expert 3410 points

Thanks for your reply Dylan, this video is very helpful!

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SN74LVC1G80-Q1: Feasibility of using with momentary contact switch in dome lighting application