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Entry  Tue Aug 13 19:03:05 2019, Shalika Singh, Noise Budget, 2micronLasers, Noise Analysis of Voltage Regulator Circuit using SR785 Spectrum Analyzer regulator.pdfNoise_across_Voltage_Regulator.pdfregulator.zip
    Reply  Thu Aug 15 08:03:13 2019, rana, Noise Budget, 2micronLasers, Noise Analysis of Voltage Regulator Circuit using SR785 Spectrum Analyzer 
       Reply  Thu Aug 15 08:36:29 2019, Shalika, Noise Budget, 2micronLasers, Noise Analysis of Voltage Regulator Circuit using SR785 Spectrum Analyzer 
    Reply  Fri Aug 30 05:11:11 2019, Chris, Noise Budget, 2micronLasers, Noise Analysis of Voltage Regulator Circuit using SR785 Spectrum Analyzer 
Message ID: 2396     Entry time: Tue Aug 13 19:03:05 2019     Reply to this: 2401   2413
Author: Shalika Singh 
Type: Noise Budget 
Category: 2micronLasers 
Subject: Noise Analysis of Voltage Regulator Circuit using SR785 Spectrum Analyzer 

As it was observed that normal voltage supply is noisy and not suitable for our circuit, we plan to use a voltage regulator that will help us provide a clean supply. Referring to previous elog entries the corresponding corrections were made( polarity of electrolytic capacitors, ceramic cap in parallel to electrolytic, 3V difference between input and output of respective regulators).

Attachment 1: The Circuit Diagram of Voltage regulator

The component used                   Input Voltage                              Output Voltage

a. LM7915                                    -18 V                                  -15.1 V

b. LM7815                                    18 V                                    14.86 V

c. LM317                                      18 V                                   14.96 V      

Attachment 2: Output Voltage noise of regulator circuit

The noise observed using SR785 at the output of each regulator is shown. It clearly shows that LM317 manifests less noise in comparison to LM7915 and LM7815. It will be therefore a good idea to use this to provide 15V bias in our circuit.

Attachment 3: The Scripts

Find all the scripts and data used in this measurement.

Attachment 1: regulator.pdf  295 kB  Uploaded Tue Aug 13 20:05:10 2019  | Hide | Hide all
regulator.pdf
Attachment 2: Noise_across_Voltage_Regulator.pdf  125 kB  Uploaded Tue Aug 13 20:16:52 2019  | Hide | Hide all
Noise_across_Voltage_Regulator.pdf
Attachment 3: regulator.zip  369 kB  Uploaded Thu Aug 15 23:04:52 2019
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