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-rw-r--r--nl_examples/opamp.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/nl_examples/opamp.c b/nl_examples/opamp.c
index 7e62d405b01..d3dc80f76a9 100644
--- a/nl_examples/opamp.c
+++ b/nl_examples/opamp.c
@@ -97,3 +97,91 @@ NETLIST_START(opamp)
NET_C(EBUF.IP, RP1.1)
NETLIST_END()
+
+NETLIST_START(opamp_mod)
+
+ /* Opamp model from
+ *
+ * http://www.ecircuitcenter.com/Circuits/opmodel1/opmodel1.htm
+ *
+ * MB3614 Unit Gain frequency is about 500 kHz and the first pole frequency
+ * about 5 Hz. We have to keep the Unity Gain Frequency below our sampling
+ * frequency of 24 Khz.
+ *
+ * Simple Opamp Model Calculation
+ *
+ * First Pole Frequency 5 Hz
+ * Unity Gain Frequency 11,000 Hz
+ * RP 100,000 Ohm
+ * DC Gain / Aol 2200
+ * CP 0.318 uF
+ * KG 0.022
+ *
+ */
+
+ /* Terminal definitions for calling netlists */
+
+ ALIAS(PLUS, G1.IP) // Positive input
+ ALIAS(MINUS, G1.IN) // Negative input
+ ALIAS(OUT, EBUF.OP) // Opamp output ...
+
+ AFUNC(fUH, 1, "A0 1.2 -")
+ AFUNC(fUL, 1, "A0 1.2 +")
+
+ ALIAS(VCC, fUH.A0) // VCC terminal
+ ALIAS(GND, fUL.A0) // VGND terminal
+
+ AFUNC(fVREF, 2, "A0 A1 + 0.5 *")
+ NET_C(fUH.A0, fVREF.A0)
+ NET_C(fUL.A0, fVREF.A1)
+
+ NET_C(EBUF.ON, fVREF)
+ /* The opamp model */
+
+ LVCCS(G1)
+ PARAM(G1.RI, RES_K(1000))
+#if 0
+ PARAM(G1.G, 0.0022)
+ RES(RP1, 1e6)
+ CAP(CP1, 0.0318e-6)
+#else
+ PARAM(G1.G, 0.002)
+ PARAM(G1.CURLIM, 0.002)
+ RES(RP1, 9.5e6)
+ CAP(CP1, 0.0033e-6)
+#endif
+ VCVS(EBUF)
+ PARAM(EBUF.RO, 50)
+ PARAM(EBUF.G, 1)
+
+ NET_C(G1.ON, fVREF)
+ NET_C(RP1.2, fVREF)
+ NET_C(CP1.2, fVREF)
+ NET_C(EBUF.IN, fVREF)
+
+ NET_C(RP1.1, G1.OP)
+ NET_C(CP1.1, RP1.1)
+
+ DIODE(DP,"D(IS=1e-15 N=1)")
+ DIODE(DN,"D(IS=1e-15 N=1)")
+#if 1
+ NET_C(DP.K, fUH.Q)
+ NET_C(fUL.Q, DN.A)
+ NET_C(DP.A, DN.K, RP1.1)
+#else
+ /*
+ * This doesn't add any performance by decreasing iteration loops.
+ * To the contrary, it significantly decreases iterations
+ */
+ RES(RH1, 0.1)
+ RES(RL1, 0.1)
+ NET_C(DP.K, RH1.1)
+ NET_C(RH1.2, fUH.Q)
+ NET_C(fUL.Q, RL1.1)
+ NET_C(RL1.2, DN.A)
+ NET_C(DP.A, DN.K, RP1.1)
+
+#endif
+ NET_C(EBUF.IP, RP1.1)
+
+NETLIST_END()