SLYW038D September 2014 – April 2025 AFE030 , AFE031 , AFE032 , ALM2402-Q1 , LMC6035-Q1 , LMV601 , LMV602 , LMV604 , LMV611 , LMV612 , LMV614 , LMV881 , OPA1602 , OPA1604 , OPA1612 , OPA1612-Q1 , OPA1622 , OPA1652 , OPA1654 , OPA1662 , OPA1662-Q1 , OPA1664 , OPA1688 , OPA170 , OPA170-EP , OPA171-Q1 , OPA172 , OPA180 , OPA188 , OPA191 , OPA192 , OPA197 , OPA211-EP , OPA2170 , OPA2171 , OPA2171-EP , OPA2171-Q1 , OPA2172 , OPA2180 , OPA2188 , OPA2192 , OPA2211-EP , OPA2211-HT , OPA2227-EP , OPA2277-EP , OPA2313 , OPA2314 , OPA2314-EP , OPA2314-Q1 , OPA2316 , OPA2317 , OPA2320-Q1 , OPA2322-Q1 , OPA2376-Q1 , OPA2625 , OPA313 , OPA314 , OPA316 , OPA317 , OPA320 , OPA322 , OPA348-Q1 , OPA355-Q1 , OPA4170 , OPA4171 , OPA4171-Q1 , OPA4172 , OPA4180 , OPA4188 , OPA4192 , OPA4277-EP , OPA4313 , OPA4314 , OPA4316 , OPA4317 , OPA4322 , OPA4322-Q1 , OPA549-HIREL , OPA564-Q1 , OPA625 , SM73307 , SM73308 , TLC2274-HT , TLE2141-Q1 , TLV2314 , TLV2316 , TLV2333 , TLV27L2-Q1 , TLV314 , TLV316 , TLV333 , TLV4314 , TLV4316 , TLV4333
Loaded open-loop gain
Feedback factor
Closed-loop noise gain
Loop gain
Where
VO = the voltage at the output of the op amp
VOUT = the voltage output delivered to the load, which may be important to the application but is not considered in stability analysis
VFB = feedback voltage
RF, R1, RiS0 and CL = the op amp feedback network and load. Other op amp topologies will have different feedback networks; however, the test circuit will be the same for most cases. Figure 50 shows the exception to the rule (multiple feedback).
C1 and L1 = components that facilitate SPICE analysis. They are large (1TF, 1TH) to make the circuit closed-loop for DC, but open loop for AC frequencies. SPICE requires closed-loop operation at DC for convergence.
Loaded open loop gain
Feedback factor
Closed-loop noise gain
Loop gain
Where
VO = the voltage at the output of the op amp
VOUT = the voltage output delivered to the load. This may be important to the application but is not considered in stability analysis.
VFB = feedback voltage
RF, R1, Riso and CF = the op amp feedback network. Because there are two paths for feedback, the loop is broken at the input.
C1 and L1 = components that facilitate SPICE analysis. They are large (1TF, 1TH) to make the circuit closed loop for DC, but open loop for AC frequencies. SPICE requires closed-loop operation at DC for convergence.
CIN = the equivalent input capacitance taken from the op amp datasheet. This capacitance normally does not need to be added because the model includes it. However, when using this simulation method the capacitance is isolated by the 1TH inductor.