Datasheet
SN54ABT18245A, SN74ABT18245A
SCAN TEST DEVICES
WITH 18-BIT BUS TRANSCEIVERS
SCBS110H – AUGUST 1992 – REVISED FEBRUARY 1999
26
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 14)
SN54ABT18245A SN74ABT18245A
UNIT
MIN MAX MIN MAX
UNIT
f
clock
Clock frequency TCK 0 50 0 50 MHz
t
w
Pulse duration TCK high or low 8.1 8.1 ns
A, B, DIR, or OE before TCK↑ 9.5 7
t
su
Setup time
TDI before TCK↑
4.5 4.5
ns
TMS before TCK↑ 3.6 3.6
A, B, DIR, or OE after TCK↑ 0.7 0
t
h
Hold time
TDI after TCK↑
0 0
ns
TMS after TCK↑ 0.5 0.5
t
d
Delay time Power up to TCK↑ 50* 50 ns
t
r
Rise time V
CC
power up 1* 1 µs
* On products compliant to MIL-PRF-38535, these parameters are not production tested.
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 14)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
= 5 V,
T
A
= 25°C
SN54ABT18245A SN74ABT18245A
UNIT
(INPUT)
(OUTPUT)
MIN TYP MAX MIN MAX MIN MAX
t
PLH
AorB
BorA
1.5 2.8 4.1 1.5 5.1 1.5 4.8
ns
t
PHL
A
or
B
B
or
A
1.5 3.1 4.6 1.5 5.8 1.5 5.4
ns
t
PZH
OE
BorA
2 4.7 5.8 2 8.1 2 7.5
ns
t
PZL
OE
B
or
A
2 4.5 6.2 2 8.5 2 8
ns
t
PHZ
OE
BorA
2.5 5.8 6.8 2.5 9.5 2.5 8.5
ns
t
PLZ
OE
B
or
A
2.5 4.8 6 2.5 8.5 2.5 7.5
ns
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 14)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
= 5 V,
T
A
= 25°C
SN54ABT18245A SN74ABT18245A
UNIT
(INPUT)
(OUTPUT)
MIN TYP MAX MIN MAX MIN MAX
f
max
TCK↓ 50 90 50 50 MHz
t
PLH
TCK↓
AorB
3 7.1 10.1 2.8 14 3 13.1
ns
t
PHL
TCK↓
A
or
B
3 7 10.1 3 13.8 3 12.8
ns
t
PLH
TCK↓
TDO
2 3.4 5 2 6.4 2 6.1
ns
t
PHL
TCK↓
TDO
2 3.9 5.6 2 7 2 6.5
ns
t
PZH
TCK↓
AorB
4 7.5 10.6 4 14.1 4 13.4
ns
t
PZL
TCK↓
A
or
B
4 7.6 10.5 4 14.3 4 13.6
ns
t
PZH
TCK↓
TDO
2 3.8 5.5 2 7 2 6.6
ns
t
PZL
TCK↓
TDO
2.5 4 5.7 2.3 7.3 2.5 6.9
ns
t
PHZ
TCK↓
AorB
3.5 7.7 10.8 2.9 14.4 3.5 13.6
ns
t
PLZ
TCK↓
A
or
B
2.5 7.1 10.1 2.5 13.8 2.5 12.7
ns
t
PHZ
TCK↓
TDO
2 3.9 5.7 2 7.5 2 7.2
ns
t
PLZ
TCK↓
TDO
1.5 3.5 5.4 1.5 6.7 1.5 6.3
ns