1. ECE 2799 Electrical and Computer Engineering Design “Op-Amp Selection” Prof. Bitar

2. S. J. Bitar - 2007 Ideal Op-Amp Characteristics Input Resistance (Rin = ∞) Input Resistance (Rin = ∞) Open Loop Voltage Gain (A = ∞) Open Loop Voltage Gain (A = ∞) Output Resistance (Rout = 0) Output Resistance (Rout = 0) Input Voltage Range (+/- ∞) Input Voltage Range (+/- ∞) Output Voltage Range (+/- ∞) Output Voltage Range (+/- ∞) Output Current Limit (+/- ∞) Output Current Limit (+/- ∞) Bandwidth (∞) Bandwidth (∞) Av in Rout Rin v in V out Linear Model

3. S. J. Bitar - 2007 Real Op-Amp Limitations Output Voltage Range Limits Output Voltage Range Limits Output Current Limit Output Current Limit Bandwidth Limit Bandwidth Limit Slew Rate Slew Rate Input Offset Voltages Input Offset Voltages Input Bias Currents Input Bias Currents Input Voltage Range Input Voltage Range Single Supply & Low Voltage Concerns Single Supply & Low Voltage Concerns

4. S. J. Bitar - 2007 Output Voltage Range Limits Clipping at (or below) Supply Rails

5. S. J. Bitar - 2007 Output Current Limit Check Output Current Spec

6. S. J. Bitar - 2007 Bandwidth Limitation Gain x BW = Constant Check Gain Bandwidth Product (GBWP) Spec

7. S. J. Bitar - 2007 Slew Rate Limitation (V/μsec)

8. V OFFSET 994.72 μV S. J. Bitar - 2007 Input Offset Voltage V+ V- V+ V- V+ Vout1 - + + OP1 uA741 V1 10V V2 10V R2 1M R1 1k Vout1 - + + OP1 uA741 R2 1M R1 1k P1 100k R3 1M 205.89uV 1.06V

9. S. J. Bitar - 2007 Input Bias Currents

10. S. J. Bitar - 2007 Input Voltage Range Issues Keep V- < Vin < V+ Excessive Input Currents due to ESD Diode Protected Inputs

11. S. J. Bitar - 2007 Input Voltage Range Issues Add Current Limiting Resistor

12. S. J. Bitar - 2007 Input Voltage Range Issues Vout Phase Inversion and Clipping w/ JFET Input Op-Amps

13. S. J. Bitar - 2007 Input Voltage Range Issues Diode Clamp Fix (for JFET Input Op-Amps)

14. S. J. Bitar - 2007 Single Supply & Low Voltage Concerns LM741 - A Bad Choice for Low Voltage Single Supply Applications

15. S. J. Bitar - 2007 Single Supply & Low Voltage Concerns Improvement: Reaching the Ground Rail with the LM124, LM358

16. S. J. Bitar - 2007 Low Voltage Single Supply Solutions “Rail-To-Rail” Input AND/OR Output (CMOS) Op-Amps

17. S. J. Bitar - 2007 Single Supply Issues Problem: Output Cannot Swing Negative Typical Inverting Amplifier

18. S. J. Bitar - 2007 Single Supply Issues Solution:Bias Ground Points to Vcc/2 Use Capacitive Coupling to Block DC and Pass AC NOTE:Output Centered Around Vcc/2 (4.5V)

19. Copyright - Stephen J. Bitar 2006 Single-Supply Issues Non-Inverting Amplifier

20. Copyright - Stephen J. Bitar 2006 Single-Supply Issues Difference Amplifier

21. Copyright - Stephen J. Bitar 2006 Single-Supply Issues Schmitt Trigger Oscillator