12/17/2011
2
Found Specifications
Differential amplifier topology PMOS Folded Cascode
Reference topology Bandgap Reference
Minumum Supply Voltage (V) 4.12
Maximum Supply Voltage (V) 5
Gain of differential amplifier (dB) 96
CMRR (dB) 144
Reference power consumption (W) 225
OpAmp power consumption with zero
input (uW) 300
OpAmp power consumption with no
load (uW) 300
Total power consumption (W) 525
Positive Slew Rate (V/s) 9.8V/s
Negative Slew Rate (V/s) 7.2V/s
ICMR (Vmin ~ Vmax) -0.65V 3.37V
Output Swing (Vmin ~ Vmax) 0.5V-4.5V
VDD PSRR (dB) 52
GND PSRR (dB) 52
Nominal output voltage (V) 2.72
Input offset voltage (mV) 190.36
Unloaded Bandwidth (kHz) 2.79
Loaded Bandwidth (kHz) 1.5
Gainbandwidth product (MHz) 270
Compensation capacitor (pF) 2.5
Phase margin (degrees) 52
Rise time (s) 2.26
Fall time (ns) 371
Settling time (ns) 0
Input referred noise (V/Hz^0.5) 32.56
THD for full swing output (%) 4.40
Calculations
Calculate Compensation Capacitor for the Opamp
CC 0.25 CL:=
CC 2.5 pF=
Calculate Minimum Bias Current that Iss should be greater
than
Ibias CC SR:=
Ibias 2.5 107
m4kg
2
A3s6
pF=
The minimum bias current that is required is 25 microamps
Calculate VGS1 of M1 and VSG3 of M3 in the Differential
Amplifier
VSG1 VTHP 2ISS
2
Lp
Kp Wp+:=
VSG1 1.124V=
VSG2 VTHP 2ISS
2
Lp
Kp Wp+:=
VSG2 1.124V=
Calculate ICMR of the Differential Amplifier
VICMR_min VSD_SAT VTHP:=
VICMR_min 0.65 V=
VICMR_max VDD 2VSD_SAT VSG1:=
VICMR_max 3.376V=
Calculate Output Voltage Swing
Vout_min 2VDS_SAT:=
Vout_min 0.5V=
Vout_max VDD 2VSD_SAT:=
Vout_max 4.5V=
Calculate ROUT of the Differential Amplifier
rout1
n p+
2
ISS
:=
rout 2.963M=
12/17/2011
10
Exceeded Specifications
Differential amplifier topology PMOS Folded Cascode
Reference topology Bandgap Reference
Minumum Supply Voltage (V) 4.12
Maximum Supply Voltage (V) 5
Gain of differential amplifier (dB) 96
CMRR (dB) 144
Reference power consumption (W) 225
OpAmp power consumption with zero
input (W) 300
OpAmp power consumption with no
load (uW) 300
Total power consumption (W) 525
Positive Slew Rate (V/s) 9.8
Negative Slew Rate (V/s) 7.2
ICMR (Vmin ~ Vmax) -0.65 3.37
Output Swing (Vmin ~ Vmax) 0.5 -4.5
VDD PSRR (dB) 52
GND PSRR (dB) 52
Nominal output voltage (V) 2.72
Input offset voltage (mV) 190.36
Unloaded Bandwidth (kHz) 2.79
Loaded Bandwidth (kHz) 1.5
Gainbandwidth product (MHz) 270
Compensation capacitor (pF) 2.5
Phase margin (degrees) 52
Rise time (ns) 2.26
Fall time (ns) 371
Settling time (ns) 0
Input referred noise (V/Hz^0.5) 32.56
THD for full swing output (%) 4.40
Unmatched Specifications
Differential amplifier topology PMOS Folded Cascode
Reference topology Bandgap Reference
Minumum Supply Voltage (V) 4.12
Maximum Supply Voltage (V) 5
Gain of differential amplifier (dB) 96
CMRR (dB) 144
Reference power consumption (W) 225
OpAmp power consumption with zero
input (uW) 300
OpAmp power consumption with no
load (uW) 300
Total power consumption (W) 525
Positive Slew Rate (V/s) 9.8
Negative Slew Rate (V/s) 7.2
ICMR (Vmin ~ Vmax) -0.65 3.37
Output Swing (Vmin ~ Vmax) 0.5 -4.5
VDD PSRR (dB) 52
GND PSRR (dB) 52
Nominal output voltage (V) 2.72
Input offset voltage (mV) 190.36
Unloaded Bandwidth (kHz) 2.79
Loaded Bandwidth (kHz) 1.5
Gainbandwidth product (MHz) 270
Compensation capacitor (pF) 2.5
Phase margin (degrees) 52
Rise time (ns) 2.26
Fall time (ns) 371
Settling time (ns) 0
Input referred noise (V/Hz^0.5) 32.56
THD for full swing output (%) 4.40
