This document summarizes the modeling of a Toshiba TC74VHCT244AFW CMOS digital integrated circuit. It includes: 1. The component details, manufacturer, and part number. 2. Simulation results of the truth table, input/output waveforms, and comparisons to measurement data with less than 1% error. 3. Timing analyses of propagation delay, input/output voltage levels, and output enable/disable times with simulation matches to measurement within 1.5%.

1. Device Modeling Report
COMPONENTS : CMOS DIGITAL INTEGRATED CIRCUIT
PART NUMBER : TC74VHCT244AFW
MANUFACTURER : TOSHIBA
Bee Technologies Inc.
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

2. Truth Table
Circuit simulation result
U1:1GBAR 0
U1:2GBAR 0
U1:1A1 0
U1:1A2 0
U1:1A3 0
U1:1A4 0
U1:2A1 0
U1:2A2 0
U1:2A3 0
U1:2A4 0
U1:1Y1 0
U1:1Y2 0
U1:1Y3 0
U1:1Y4 0
U1:2Y1 0
U1:2Y2 0
U1:2Y3 0
U1:2Y4 0
0s 0.5us 1.0us
Time
Evaluation circuit
_ U1
1G VCC
LO
_
1A1 2G
LO LO
2Y4 1Y1
1A2 2A4
LO LO
2Y3 1Y2
1A3 2A3
LO LO
R1 V1
2Y2 1Y3
1MEG
1A4 2A2
LO LO
5
2Y1 1Y4
GND 2A1
LO
VHCT244A
0
Comparison table
Input Output
%Error
G An Yn (Measurement) Yn (Simulation)
L L L L 0
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

3. Truth Table
Circuit simulation result
U1:1GBAR 0
U1:2GBAR 0
U1:1A1 1
U1:1A2 1
U1:1A3 1
U1:1A4 1
U1:2A1 1
U1:2A2 1
U1:2A3 1
U1:2A4 1
U1:1Y1 1
U1:1Y2 1
U1:1Y3 1
U1:1Y4 1
U1:2Y1 1
U1:2Y2 1
U1:2Y3 1
U1:2Y4 1
0s 0.5us 1.0us
Time
Evaluation circuit
_ U1
1G VCC
LO
_
HI
1A1 2G
LO
2Y4 1Y1
HI
1A2 2A4 HI
2Y3 1Y2
HI
1A3 2A3 HI
R1 V1
2Y2 1Y3
1MEG
HI
1A4 2A2 HI
5
2Y1 1Y4
GND 2A1 HI
VHCT244A
0
Comparison table
Input Output
%Error
G An Yn (Measurement) Yn (Simulation)
L H H H 0
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

4. Truth Table
Circuit simulation result
U1:1GBAR 1
U1:2GBAR 1
U1:1A1 0
U1:1A2 0
U1:1A3 0
U1:1A4 0
U1:2A1 0
U1:2A2 0
U1:2A3 0
U1:2A4 0
U1:1Y1 Z
U1:1Y2 Z
U1:1Y3 Z
U1:1Y4 Z
U1:2Y1 Z
U1:2Y2 Z
U1:2Y3 Z
U1:2Y4 Z
0s 0.5us 1.0us
Time
Evaluation circuit
_ U1
HI 1G VCC
_
1A1 2G HI
2Y4 1Y1
1A2 2A4
X
2Y3 1Y2
1A3 2A3
X V1
R1
2Y2 1Y3
1MEG
DSTM1
CLK 1A4 2A2
5
OFFTIME = .2uS 2Y1 1Y4
ONTIME = .2uS
GND 2A1
VHCT244A
0
Comparison table
Input Output
%Error
G An Yn (Measurement) Yn (Simulation)
H X Z Z 0
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

5. High Level and Low Level Input Voltage
Circuit simulation result
5.0V
Output
(540.005u,2.0003)
2.5V Input
(515.984u,799.195m)
0V
0s 0.5ms 1.0ms 1.5ms 2.0ms
V(OUT) V(V1:+)
Time
Evaluation circuit
_ U1
1G VCC
LO
_
1A1 2G
LO
2Y4 1Y1
OUT
1A2 2A4
2Y3 1Y2 V2
V1 = 0 V1 1A3 2A3
V2 = 5 R1
TD = 0.5m 2Y2 1Y3 5
TR = 0.1m 1G
TF = 0.1m 1A4 2A2
PW = 1m
PER = 2m 2Y1 1Y4
GND 2A1
VHCT244A
0
Comparison table
VCC = 5V Measurement Simulation %Error
VIH (V) 2 2 0
VIL (V) 0.8 0.799195 -0.101
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

6. High Level and Low Level Output Voltage
Circuit simulation result
5.0V
2.5V
Output
SEL>>
0V Input
V(OUT)
5.0V
2.5V
0V
0s 5ms 10ms
V(U1:1A1)
Time
Evaluation circuit
_ U1
1G VCC
LO
_
1A1 2G
LO
2Y4 1Y1
OUT
1A2 2A4
2Y3 1Y2 V2
V1 = 0 1A3 2A3
V2 = 4.5 V1
TD = 0.5m 2Y2 1Y3 4.5
TR = 3n R1
TF = 3n 1A4 2A2
PW = 1m 0.09MEG
PER = 2m 2Y1 1Y4
GND 2A1
VHCT244A
0
Comparison table
VCC = 4.5V Measurement Simulation %Error
VOH (V) 4.5 4.4976 -0.053
VOL (V) 0 0 0
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

7. Propagation Delay Time
Circuit simulation result
5.0V 3.0V
1 2
Output
Input
2.5V 1.5V
>>
0V 0V
0s 0.5us 1.0us
1 V(TPLH_TPHL) 2 V(V1:+)
Time
Evaluation circuit
_ U1
1G VCC
LO
_
1A1 2G
LO
tplh_tphl
2Y4 1Y1
1A2 2A4
2Y3 1Y2
V1 = 0
V2 = 3 1A3 2A3 V2
TD = 0.2u V1
TR = 3.8n 2Y2 1Y3 C1
TF = 3.8n
PW = 0.5u 1A4 2A2 50p 5
PER = 1u
2Y1 1Y4
GND 2A1
VHCT244A
0
Comparison table CL = 50 pF
tr = tf =3 ns Measurement Simulation %Error
tPLH (ns) 5.9 5.9782 1.325
tPHL (ns) 5.9 5.9327 0.554
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

8. Output enable time, high impedance (off) to high output (tPZH)
Output disable time, high to high impedance (off) output (tPHZ)
Circuit simulation result
5.0V 3.0V
1 2
Output
Input
2.0V
2.5V
1.0V
>>
0V 0V
0s 0.5us 1.0us
1 V(TPHZ_TPZH) 2 V(V1:+)
Time
Evaluation circuit
_ U1
1G VCC
_
HI
1A1 2G HI
tphz_tpzh
2Y4 1Y1
1A2 2A4
2Y3 1Y2
V1 = 0
V2 = 3 1A3 2A3 V2
TD = 0.2u V1 C1
TR = 3.8n 2Y2 1Y3 R1 R2
TF = 3.8n 50p
PW = 0.5u 1A4 2A2 1k 1k 5
PER = 1u
2Y1 1Y4
GND 2A1
VHCT244A
0
Comparison table CL = 50 pF, RL = 1 K
tr = tf =3 ns Measurement Simulation %Error
tPZH (ns) 8.2 8.2441 0.538
tPHZ (ns) 8.8 8.9224 1.391
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005

9. Output enable time, high impedance (off) to low output (tPZL)
Output disable time, low to high impedance (off) output (tPLZ)
Circuit simulation result
5.0V 3.0V
1 2
Output
Input
2.5V 1.5V
>>
0V 0V
0s 0.5us 1.0us
1 V(TPZL_TPLZ) 2 V(V1:+)
Time
Evaluation circuit
_ U1
1G VCC
_
1A1 2G HI
LO
tpzl_tplz
2Y4 1Y1
1A2 2A4
2Y3 1Y2 R2
V1 = 0
V2 = 3 1A3 2A3 1k
TD = 0.2u V1 V3
TR = 3n 2Y2 1Y3 C1 R1
TF = 3n
PW = 0.5u 1A4 2A2 50p 1k
PER = 1u V2 5
2Y1 1Y4
GND 2A1 10
VHCT244A
0
Comparison table CL = 50 pF, RL = 1 K
tr = tf =3 ns Measurement Simulation %Error
tPZL (ns) 8.2 8.2238 0.290
tPLZ (ns) 8.8 8.8277 0.315
All Rights Reserved Copyright (c) Bee Technologies Inc. 2005