Thursday, 10 October 2013

Op_Amp_Openloop_Operation_with_fixed_positive_regulated_Vref_in_MATLAB


An op amp comparator outputs + Vsat when when voltage at non-inverting input exceeds the voltage at the inverting input and outputs -Vsat when the voltage at inverting input exceeds the voltage at the non-inverting input.
Check this fixed positive regulated open loop operation on op amp. The simulation in MALAB is as...



Properties of components used in circuit is as...
AC Voltage Source: 
Peak amplitude: 10 V
Phase Shift: 0 rad.
Frequency: 5 hz.
Finite Gain Op Amp:
Gain : 10
Rin = 10^6 ohm
Rout = 100 ohm
Vmin = -15 V
Vmax = +15V
Resistor:
R = 1 kOhm
Diode:
Vforward = 1 V
Ron = 0.3 ohm
Goff = 10^(-8) 1/ohm
DC Voltage Source :
1 V
Let the time period of simulation response be 2 seconds.

Now let us change the value of Resistor R = 10000 kohm. The response changes as ....

Now let the R = 1 k ohm and DC Voltage Source voltage be = 5 volt , the response changes as ....
Now when Vdc = 8 V then response changes to .....
and when Vdc = 9 V response change to ......
and when Vdc = 10 V response becomes.....
this is how op amp behaves for positive fixed regulated reference DC voltage in open loop operation.




(su317)


Rest of the details about simulink you can find below.
Op_Apm_open_loop_operation_With_fixed_Positive_Rgulated_Vref

Op_Apm_open_loop_operation_With_fixed_Positive_Rgulated_Vref

$hiv

11-Oct-2013 07:54:45

Model - Op_Apm_open_loop_operation_With_fixed_Positive_Rgulated_Vref

Simulation Parameter Value
Solver ode45
RelTol 1e-3
Refine 1
MaxOrder 5
ZeroCross on
[more info]

System - Op_Apm_open_loop_operation_With_fixed_Positive_Rgulated_Vref

Table 1. AC Voltage Source Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version Amp Amp unit Shift Shift unit Omega Omega unit I Log V Log Local Var Names Local Var Descs Local Var Logging
AC Voltage Source foundation.electrical.sources.ac_voltage foundation.electrical.sources.ac_voltage ac_voltage ac_voltage 1 10 V 0 rad 5 Hz off off |i|v |i|v [0 0]
Table 2. DC Voltage Source Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version V0 V0 unit I Log V Log Local Var Names Local Var Descs Local Var Logging
DC Voltage Source foundation.electrical.sources.dc_voltage foundation.electrical.sources.dc_voltage dc_voltage dc_voltage 1 1 V off off |i|v |i|v [0 0]
Table 3. Diode Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version Vf Vf unit Ron Ron unit Goff Goff unit I Log V Log Local Var Names Local Var Descs Local Var Logging
Diode foundation.electrical.elements.pwl_diode foundation.electrical.elements.pwl_diode pwl_diode pwl_diode 1 1 V 0.3 Ohm 1e-8 1/Ohm off off |i|v |i|v [0 0]
Table 4. Electrical Reference Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version I Log Local Var Names Local Var Descs Local Var Logging
Electrical Reference foundation.electrical.elements.reference foundation.electrical.elements.reference reference reference 1 off |i |i 0
Electrical Reference1 foundation.electrical.elements.reference foundation.electrical.elements.reference reference reference 1 off |i |i 0
Electrical Reference2 foundation.electrical.elements.reference foundation.electrical.elements.reference reference reference 1 off |i |i 0
Electrical Reference3 foundation.electrical.elements.reference foundation.electrical.elements.reference reference reference 1 off |i |i 0
Table 5. Finite Gain Op-Amp Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version A A unit Rin Rin unit Rout Rout unit Vmin Vmin unit Vmax Vmax unit Local Var Logging
Finite Gain Op-Amp elec.integrated_circuits.finitegain_opamp elec.integrated_circuits.finitegain_opamp finitegain_opamp finitegain_opamp 1 10 1 1e+6 Ohm 100 Ohm -15 V 15 V []
Table 6. PS-Simulink Converter Block Properties
Name Unit Affine Conversion
PS-Simulink Converter 1 off
Table 7. Resistor Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version R R unit I Log V Log Local Var Names Local Var Descs Local Var Logging
Resistor foundation.electrical.elements.resistor foundation.electrical.elements.resistor resistor resistor 1 1 kOhm off off |i|v |i|v [0 0]
Table 8. Solver Configuration Block Properties
Name Do DC Residual Tolerance Use Local Solver Local Solver Choice Local Solver Sample Time Do Fixed Cost Max Nonlin Iter Max Mode Iter Linear Algebra Accelerate Profile Use Local Sampling Delays Memory Budget
Solver Configuration off 1e-9 off NE_BACKWARD_EULER_ADVANCER .001 off 3 2 Sparse off off off 1024
Table 9. Voltage Sensor Block Properties
Name Component Path Component Variants Component Variant Names Class Name Schema Version I1 Log V1 Log Local Var Names Local Var Descs Local Var Logging
Voltage Sensor foundation.electrical.sensors.voltage foundation.electrical.sensors.voltage voltage voltage 1 off off |i1|v1 |i1|v1 [0 0]

Appendix

Table 10. Block Type Count
BlockType Count Block Names
Electrical Reference (m) 4 Electrical Reference, Electrical Reference1, Electrical Reference2, Electrical Reference3
Voltage Sensor (m) 1 Voltage Sensor
Solver
Configuration (m)
1 Solver Configuration
Scope 1 Scope
Resistor (m) 1 Resistor
PS-Simulink
Converter (m)
1 PS-Simulink Converter
Finite Gain Op-Amp (m) 1 Finite Gain Op-Amp
Diode (m) 1 Diode
DC Voltage Source (m) 1 DC Voltage Source
AC Voltage Source (m) 1 AC Voltage Source

Open Loop Operation of Op Amp

An open loop operation of op amp which is hardly seen used this way can be studied in MATLAB with it's responses.
                                                          A_{\text{OL}}=\frac{V_{\text{out}}}{\left(V^+-V^-\right)}
An op amp can have open loop gain equal to 10^5.

The MATLAB simulation circuit which can be used is .....


This circuit can be drawn in MATLAB in it's model. MATLAB's model can approached by using
"Alt + F + M " on command window of the MATLAB. In order to get above used components you have to surf  "Simulink Library Browser" of MATLAB, for which all you need to do is to type 'simulink' in your MATLAB command window.

Simulating the above circuit we get a beautiful response in the Scope as...


Let the time period of simulation be set to 1 second and gain A be set to 10. Change the values of gain A to see change in response.