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Message ID: 2226     Entry time: Mon Aug 13 17:36:39 2018
Author: anchal 
Type: Summary 
Category: PD 
Subject: Photodiode Transimpedance Amplification Circuit 

Redesigned D1400384-v2 is ready and uploaded on dcc. PCB Layout, circuit schematic, Gerber files, LISO analysis, front panel and full BOM are attached.
The circuit is kept the same except for replacing LT1128 with OPA827 in the transimpedance amplifier stages and adding few OMIT and ZERO resistances to have more options for using the circuit. Following are the notes (also present as ReadMe.txt in the .zip file in dcc):

1) To not have whitening option, do not populate IC5, U8, U9 and their peripheral resistors and capacitors and put a 0 Ohm resistor (Jumper) at R20 and R26

2) To have fixed transimpedance, do not populate IC8 and its peripheral resistors and capacitors and populate R7 and R22 with the desired transimpedance.

3) In case of switchable transimpedance, R11=R15=100 and R14=R28=10k are the two options in present design. These can also be changed according to choice. Mark the front panel accordingly with the choices.

4) For low transimpedances, it is better to replace U5 and U7 with LT1128 instead.

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