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university:courses:electronics:electronics-lab-nr [01 Mar 2019 16:04]
amiclaus [Procedure:]
university:courses:electronics:electronics-lab-nr [23 Aug 2019 14:06]
amiclaus
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 ====Testing supply headroom==== ====Testing supply headroom====
  
-To test the headroom requirements for +V<​sub>​DD</​sub>,​ disconnect the fixed positive power supply from +V<​sub>​DD</​sub>​ and remove any supply decoupling capacitors. Be sure to turn off the power supplies before making any changes or additions to your breadboard. Now connect +V<​sub>​DD</​sub>​ to AWG 1. Set AWG 1 to trapezium (trapezoid) ​ waveform at 100 Hz. Set the amplitude to 5V with a 2.5V offset for a 0 to +5V swing. Connect scope channel 1 to the output of AWG1 and connect scope channel 2 to -V<​sub>​REF</​sub>​ of the first example circuit at pin 14 of the OP482. Use the oscilloscope instrument in the XY mode, scope channel for X and scope channel 2 for Y. Start AWG 1 and turn on the fixed negative 5V  power supply. Record the minimum +V<​sub>​DD</​sub>​ voltage where -V<​sub>​REF</​sub>​ starts to remain constant at -1.25V.+To test the headroom requirements for +V<​sub>​DD</​sub>,​ disconnect the fixed positive power supply from +V<​sub>​DD</​sub>​ and remove any supply decoupling capacitors. Be sure to turn off the power supplies before making any changes or additions to your breadboard. Now connect +V<​sub>​DD</​sub>​ to AWG 1. Set AWG 1 to trapezium (trapezoid) ​ waveform at 100 Hz. Set the amplitude to 5V peak-to-peak ​with a 2.5V offset for a 0 to +5V swing. Connect scope channel 1 to the output of AWG1 and connect scope channel 2 to -V<​sub>​REF</​sub>​ of the first example circuit at pin 14 of the OP482. Use the oscilloscope instrument in the XY mode, scope channel for X and scope channel 2 for Y. Start AWG 1 and turn on the fixed negative 5V  power supply. Record the minimum +V<​sub>​DD</​sub>​ voltage where -V<​sub>​REF</​sub>​ starts to remain constant at -1.25V.
  
-To test the headroom requirements for -V<​sub>​SS</​sub>,​ reconnect +V<​sub>​DD</​sub>​ to the fixed positive power supply. Disconnect the fixed negative power supply from -V<​sub>​SS</​sub>​ and remove any supply decoupling capacitors. Now connect -V<​sub>​SS</​sub>​ to AWG 1. Set the amplitude to 5V with a -2.5V offset for a 0 to -5V swing. Start AWG 1 and turn on the fixed positive 5V  power supply. Repeat your measurements of pins 14 of the OP482 recording the lowest value for -V<​sub>​SS</​sub>​ where the reference voltage is constant.+To test the headroom requirements for -V<​sub>​SS</​sub>,​ reconnect +V<​sub>​DD</​sub>​ to the fixed positive power supply. Disconnect the fixed negative power supply from -V<​sub>​SS</​sub>​ and remove any supply decoupling capacitors. Now connect -V<​sub>​SS</​sub>​ to AWG 1. Set the amplitude to 5V peak-to-peak ​with a -2.5V offset for a 0 to -5V swing. Start AWG 1 and turn on the fixed positive 5V  power supply. Repeat your measurements of pins 14 of the OP482 recording the lowest value for -V<​sub>​SS</​sub>​ where the reference voltage is constant.
  
 =====Directions Step 3:===== =====Directions Step 3:=====
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 Repeat the supply headroom tests you did in Step 2 for this configuration. Are there any differences?​ Repeat the supply headroom tests you did in Step 2 for this configuration. Are there any differences?​
  
 +<WRAP round download>​
 **Resources:​** **Resources:​**
   * Fritzing files: [[ https://​minhaskamal.github.io/​DownGit/#/​home?​url=https://​github.com/​analogdevicesinc/​education_tools/​tree/​master/​m2k/​fritzing/​neg_voltage_ref_bb | neg_voltage_ref_bb]]   * Fritzing files: [[ https://​minhaskamal.github.io/​DownGit/#/​home?​url=https://​github.com/​analogdevicesinc/​education_tools/​tree/​master/​m2k/​fritzing/​neg_voltage_ref_bb | neg_voltage_ref_bb]]
   * LTspice files: [[ https://​minhaskamal.github.io/​DownGit/#/​home?​url=https://​github.com/​analogdevicesinc/​education_tools/​tree/​master/​m2k/​ltspice/​neg_voltage_ref_ltspice | neg_voltage_ref_ltspice]]   * LTspice files: [[ https://​minhaskamal.github.io/​DownGit/#/​home?​url=https://​github.com/​analogdevicesinc/​education_tools/​tree/​master/​m2k/​ltspice/​neg_voltage_ref_ltspice | neg_voltage_ref_ltspice]]
 +</​WRAP>​
 ====For further reading:​==== ====For further reading:​====
  
university/courses/electronics/electronics-lab-nr.txt · Last modified: 23 Aug 2019 14:06 by amiclaus