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Message ID: 2384     Entry time: Thu Aug 8 17:19:12 2019
Author: Shalika Singh 
Type: Noise Budget 
Category: 2micronLasers 
Subject: Noise Analysis of TIA using SR785 Spectrum Analyser and Zero Simulation 

Input Referred noise to be calculated for trans-impedance.

Attachment 1: The Circuit Diagram on paper,

>>  the TIA with a gain of 5.1k

Attachment 2: Noise across TIA 

The input-referred current noise across the TIA was measured using SR785 and was compared against the graph obtained from ZERO simulation.

** This time, I divided the measurements into 7 parts, 0-800, 800-2.4k, 2.4k-5.6k, 5.6k-12k, 12k-24.8k, 24.8k-50.4k, 50.4k-101.6k. The number of points for each was 800. Hanning Window function was used in the template file and the Input channels were grounded. 

Attachment 3: Noise across TIA 

The input-referred current noise across the TIA was measured using SR785 and was compared against the graph obtained from ZERO simulation.

** This time, I divided the measurements into 1 part, 10-6.4k. The number of points for each was 800. Hanning Window function was used in the template file and the Input channels were grounded. 

** To measure the noise the output was measured at the pin6 of the OpAmp.

** A source of 1V was applied to the circuit by keeping a 10k in series with the input of the circuit when Transfer Function was being measured.

** It's difficult to avoid 60Hz harmonics with a circuit kept in open as this one. Lots of its effects are visible in the plot.

 

Attachment 4: Noise of the power supply used

The power supply was observed to be used to be noisy. 

Attachment 1: TIA.pdf  16 kB  Uploaded Thu Aug 8 18:23:43 2019  | Hide | Hide all
TIA.pdf
Attachment 2: Noise_across_TIA.pdf  57 kB  Uploaded Thu Aug 8 18:25:08 2019  | Hide | Hide all
Noise_across_TIA.pdf
Attachment 3: Noise_across_TIA.pdf  27 kB  Uploaded Thu Aug 8 18:54:28 2019  | Hide | Hide all
Noise_across_TIA.pdf
Attachment 4: powersupply.pdf  3.235 MB  Uploaded Thu Aug 8 19:18:12 2019  | Hide | Hide all
powersupply.pdf
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