Analog Integrated Circuit Design

2nd edition


Example 6.11

1. Unity-gain frequency

1-1. Schematic

1-2. HSPICE Netlist

* Example 6.11 for unity-gain frequency

 

* MOS model
.include p18_cmos_models_tt.inc

 

* main circuit (Current-mirror opamp)
* input stage
m1 4 1 3 0 nmos w=90u l=0.4u
m2 5 2 3 0 nmos w=90u l=0.4u
m3 4 8 6 9 pmos w=40u l=0.4u
m4 5 8 7 9 pmos w=40u l=0.4u
m5 6 4 9 9 pmos w=20u l=0.4u
m6 7 5 9 9 pmos w=20u l=0.4u

 

*output stage
m7 10 5 9 9 pmos w=20u l=0.4u
m8 11 4 9 9 pmos w=40u l=0.4u
m9 12 8 10 9 pmos w=20u l=0.4u
m10 16 8 11 9 pmos w=40u l=0.4u
m11 12 13 14 0 nmos w=4u l=0.4u
m12 16 13 15 0 nmos w=8u l=0.4u
m13 14 12 0 0 nmos w=4u l=0.4u
m14 15 12 0 0 nmos w=8u l=0.4u

 

*load capacitance
cl 16 0 2.5p
*cl 16 0 5p
**change cl value for 75 degree phase margin without lead compensation

 

* current source
Ibias 3 0 160u

 

* voltage source
Vdd 9 0 1.8
Vin 1 0 1 pulse(750m 1.25 0 1n 1n 49n 100n)
Vb1 13 0 1.4
Vb2 9 8 1.2
V1 2 16 dc=0 ac=1

 

* analysis
.op
.ac dec 10 1k 100G

 

* options
.options post

.end

1-3. Simulation Result

 

fta = 194 MHz (CL = 2.5pF)
Phase margin = 56degrees

fta = 104 MHz (CL = 5pF)
Phase margin = 71degrees

2. Slew rate

2-1. Schematic

2-2. HSPICE Netlist

* Example 6.11 for Slew rate

 

* MOS model
.include p18_cmos_models_tt.inc

 

* main circuit (Current-mirror opamp)
* input stage
m1 4 1 3 0 nmos w=90u l=0.4u
m2 5 2 3 0 nmos w=90u l=0.4u
m3 4 8 6 9 pmos w=40u l=0.4u
m4 5 8 7 9 pmos w=40u l=0.4u
m5 6 4 9 9 pmos w=20u l=0.4u
m6 7 5 9 9 pmos w=20u l=0.4u

 

*output stage
m7 10 5 9 9 pmos w=20u l=0.4u
m8 11 4 9 9 pmos w=40u l=0.4u
m9 12 8 10 9 pmos w=20u l=0.4u
m10 2 8 11 9 pmos w=40u l=0.4u
m11 12 13 14 0 nmos w=4u l=0.4u
m12 2 13 15 0 nmos w=8u l=0.4u
m13 14 12 0 0 nmos w=4u l=0.4u
m14 15 12 0 0 nmos w=8u l=0.4u

 

*load capacitance
cl 2 0 2.5p

 

* current source
Ibias 3 0 160u

 

* voltage source
Vdd 9 0 1.8
Vin 1 0 1 pulse(0.75 1.25 0 0.1n 0.1n 49.8n 100n)
Vb1 13 0 1.4
Vb2 9 8 1.2

 

* analysis
.op
.tran 1n 300n

 

* options
.options post

.end

 

2-3. Simulation Result

Slew rate = 104V/┬Ás



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