Part Number: TLC272
Hello,
We have been manufacturing this PCB with the same subcontractor since 2007, and this design has always worked reliably.
In the latest production batch, we are experiencing abnormal behavior on an analog stage using TLC272 op-amps.
The stage consists of:
- A transimpedance amplifier (TIA)
- Followed by band-pass and gain stages
With the latest batch, the circuit self-oscillates and outputs a saturated signal, even when the photodiode is fully covered.
When we replace the TLC272 devices with parts purchased directly from Mouser and Digi-Key, the circuit works perfectly.
This strongly indicates that the issue is related to the components used during PCBA.
After inspection, we noticed at least three different marking styles on the TLC272 devices across the boards. This seems unusual compared to previous lots.
My main question:
Is it possible that some of these devices are counterfeit or non-genuine?
I am attaching photos of:
- Two working devices from authorized distributors
- One device from the affected batch that looks suspicious
Could you please help verify whether that markings are consistent with genuine TI parts?
We need to determine this with high confidence in order to address the issue with our supplier.
Thank you for your support.
Best regards,
Federico
TLC272_OK_1 (from a previous PCBA)
TLC272_OK_2 (from Mouser and Digikey)
TLC272_NO_OK (last batch)
