suria3
Full Member level 5
Hi guys,
I did design a optical receiver circuit which to work at 1.25Gbps. The circuit consists of Transimpedance amplifier (TIA), Limiting Amplifier (LA) and Low Voltage Differential Swing (LVDS) driver. The simulated extracted results showed a sensitivity of 10uApp input current with the output LVDS swing of 350mVpp. The total current consumption of this receiver is 35mA. But when we tested the chip, we didn't get the expected sensitivity, we were only managed to get a clear eye-diagram until 50uApp input current, it was noisy output. There is a large difference in term of sensitivity of the simulated result (with noise enabled in simulator) and the tested in lab. We also did test another optical receiver chip which was designed with 12mA current consumption as for the lower power design and managed to get the good test result until 10uApp as per simulated.
So, here I would like to seek input from the people in this forum to troubleshoot on what could have gone wrong/possible factor for not achieving the simulated result.
Attached is the simulated and tested eye-diagram of the output optical receiver.
Thanks,
Suria.
I did design a optical receiver circuit which to work at 1.25Gbps. The circuit consists of Transimpedance amplifier (TIA), Limiting Amplifier (LA) and Low Voltage Differential Swing (LVDS) driver. The simulated extracted results showed a sensitivity of 10uApp input current with the output LVDS swing of 350mVpp. The total current consumption of this receiver is 35mA. But when we tested the chip, we didn't get the expected sensitivity, we were only managed to get a clear eye-diagram until 50uApp input current, it was noisy output. There is a large difference in term of sensitivity of the simulated result (with noise enabled in simulator) and the tested in lab. We also did test another optical receiver chip which was designed with 12mA current consumption as for the lower power design and managed to get the good test result until 10uApp as per simulated.
So, here I would like to seek input from the people in this forum to troubleshoot on what could have gone wrong/possible factor for not achieving the simulated result.
Attached is the simulated and tested eye-diagram of the output optical receiver.
Thanks,
Suria.