eldo_user

Examples
Example 11—Loop Stability of an Opamp
.PARAM pCX=0.2P
CX M8D OUT pCX ! COMPENSATION CAP.
CL OUT 0 1p ! LOAD CAP.
The above lines specify the circuit has a capacitive load, and a compensation capacitor is set so
that phase margin is approx. 45°.
.OPTION tuning=vhigh
The above line sets the simulator accuracy to very high.
VDD VDD 0 1.65V
VSS VSS 0 -1.65V
VB BIAS 0 0.95V
VINP INP 0 AC 1 0
The above lines specify the power supplies, bias, and input.
.ac dec 10 1 1e8
The above line indicates that an AC analysis is performed on the circuit within the frequency
range 1Hz to 100MHz with 10 steps per decade.
.LSTB VSTB
The above line indicates that a loop stability analysis is performed on the circuit.
.plot ac lstb_db
.plot ac lstb_p
The above lines request the loop stability output plots of loop gain and phase.
1300
Eldo® User's Manual, 15.3