SN74LS373: Getting inverted signal at the outputs

Nanthini Rajendran

Part Number: SN74LS373

Hi,

We are using SN74LS373DW latch in our design.

During testing, among the 8 channels of the latch we are getting inverted output at 2 channels. But all the other channels having the same output as input. (Clk is high during these conditions)

May I know what will be the reason for this?

Please help us in this issue. Attached captured waveform for reference.

Thanks,

Nanthini R.

over 2 years ago

0 Emrys Maier over 2 years ago

TI__Guru* 96752 points

Hi Nanthini,

Have you completed an A-B-A swap to see if the issue follows the part or the board?

Also, can you provide a schematic showing the connections to the LS373 (and any loading/connectors that may not show up on the schematic)?

0 Nanthini Rajendran over 2 years ago in reply to Emrys Maier

Prodigy 30 points

Hi Emrys,

We have not performed A-B-A swap.

We are doubting that the IC is failed. How to confirm it?

Thanks,

Nanthini R.

0 Emrys Maier over 2 years ago in reply to Nanthini Rajendran

TI__Guru* 96752 points

Hi Nanthini,

Providing me with a complete schematic can help me to check for any issues that may be related to the usage of the part.

Swapping the part out to another board and putting a new part in its place (A-B-A swap) can confirm whether the issue is with a single failed IC or if the design is the issue.

One other thing I thought of -- is there a bypass capacitor at the supply of this device?

0 Nanthini Rajendran over 2 years ago in reply to Emrys Maier

Prodigy 30 points

Hi Emrys,

Thanks for your reply.

Below is the schematic connection of the IC.

Please let me know if any issue in the design.

Thanks,

Nanthini R.

0 Emrys Maier over 2 years ago in reply to Nanthini Rajendran

TI__Guru* 96752 points

I can't tell anything from the provided schematic.

Logic

Logic forum

SN74LS373: Getting inverted signal at the outputs