74VCXH245 Low Voltage Bidirectional Transceiver with Bushold
June 1999
Revised April 2005
74VCXH245
Low Voltage Bidirectional Transceiver with Bushold
General Description
The VCXH245 contains eight non-inverting bidirectional
buffers with 3-STATE outputs and is intended for bus ori-
ented applications. The T/R input determines the direction
of data flow. The OE input disables both the A and B Ports
by placing them in a high impedance state. The VCXH245
data inputs include active bushold circuitry, eliminating the
need for external pull-up resistors to hold unused or float-
ing data inputs at a valid logic level.
The 74VCXH245 is designed for low voltage (1.2V to 3.6V)
V
CC
applications.
The 74VCXH245 is fabricated with an advanced CMOS
technology to achieve high-speed operation while main-
taining low CMOS power dissipation.
Features
s
1.2V to 3.6V V
CC
supply operation
s
Bushold on data inputs eliminates the need for external
pull-up/pull-down resistors
s
t
PD
3.5 ns max for 3.0V to 3.6V V
CC
s
Static Drive (I
OH
/I
OL
)
r
24 mA @ 3.0V V
CC
s
Uses patented Quiet Series
¥
noise/EMI reduction
circuitry
s
Latchup performance exceeds 300 mA
s
ESD performance:
Human body model
!
2000V
Machine model
!
200V
Ordering Code:
Order Number
74VCXH245WM
74VCXH245MTC
Package Number
M20B
MTC20
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
Pin Descriptions
Pin Names
OE
T/R
A
0
–A
7
B
0
–B
7
Description
Output Enable Input (Active LOW)
Transmit/Receive Input
Side A Bushold Inputs or 3-STATE Outputs
Side B Bushold Inputs or 3-STATE Outputs
Quiet Series
¥
is a trademark of Fairchild Semiconductor Corporation.
© 2005 Fairchild Semiconductor Corporation
DS500198
www.fairchildsemi.com
74VCXH245
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
CC
)
DC Input Voltage (V
I
)
DC Output Voltage (V
O
)
Outputs 3-STATE
0.5V to
4.6V
0.5V to
4.6V
Recommended Operating
Conditions
(Note 3)
Power Supply
Operating
Input Voltage
Output Voltage (V
O
)
Output in Active States
Output in 3-STATE
Output Current in I
OH
/I
OL
V
CC
V
CC
V
CC
V
CC
V
CC
3.0V to 3.6V
2.3V to 2.7V
1.65V to 2.3V
1.4V to 1.65V
1.2V
0V to V
CC
0V to 3.6V
1.2V to 3.6V
0.5V to
4.6V
0.5V to V
CC
0.5V
Outputs Active (Note 2)
DC Input Diode Current (I
IK
) V
I
0V
50 mA
DC Output Diode Current (I
OK
)
V
O
0V
V
O
!
V
CC
DC Output Source/Sink Current
(I
OH
/I
OL
)
DC V
CC
or Ground Current
Storage Temperature (T
STG
)
0.3V to 3.6V
50 mA
50 mA
r
50 mA
r
100 mA
65
q
C to
150
q
C
Free Air Operating Temperature (T
A
)
Minimum Input Edge Rate (
'
t/
'
V)
V
IN
0.8V to 2.0V, V
CC
3.0V
r
24 mA
r
18 mA
r
6 mA
r
2 mA
r
100
P
A
40
q
C to
85
q
C
10 ns/V
Note 1:
The Absolute Maximum Ratings are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the Absolute Maximum Rat-
ings. The “Recommended Operating Conditions” table will define the condi-
tions for actual device operation.
Note 2:
I
O
Absolute Maximum Rating must be observed.
Note 3:
Floating or unused control inputs must be held HIGH or LOW.
DC Electrical Characteristics
Symbol
V
IH
Parameter
HIGH Level Input Voltage
Conditions
V
CC
(V)
2.7 - 3.6
2.3 - 2.7
1.65 - 2.3
1.4 - 1.6
1.2
V
IL
LOW Level Input Voltage
2.7 - 3.6
2.3 - 2.7
1.65 - 2.3
1.4 - 1.6
1.2
V
OH
HIGH Level Output Voltage
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
2.0
1.6
0.65 x V
CC
0.65 x V
CC
0.65 x V
CC
0.8
0.7
0.35 x V
CC
0.35 x V
CC
0.05 x V
CC
V
CC
- 0.2
2.2
2.4
2.2
V
CC
- 0.2
2.0
1.8
1.7
V
CC
- 0.2
1.25
V
CC
- 0.2
1.05
V
CC
- 0.2
V
V
V
Min
Max
Units
100
P
A
12 mA
18 mA
24 mA
100
P
A
6 mA
12 mA
18 mA
100
P
A
6 mA
100
P
A
2 mA
100
P
A
2.7 - 3.6
2.7
3.0
3.0
2.3 - 2.7
2.3
2.3
2.3
1.65 - 2.3
1.65
1.4 - 1.6
1.4
1.2
3
www.fairchildsemi.com
74VCXH245
AC Electrical Characteristics
(Note 6)
Symbol
t
PHL
,
t
PLH
Parameter
Propagation Delay
A
n
to B
n
or B
n
to A
n
C
L
t
PZL
,
t
PZH
C
L
t
PLZ
,
t
PHZ
C
L
t
OSHL
t
OSLH
Output to Output Skew
(Note 7)
C
L
Note 6:
For C
L
Conditions
C
L
30 pF, R
L
500
:
V
CC
(V)
3.3
r
0.3
2.5
r
0.2
1.8
r
0.15
T
A
40
q
C to
85
q
C
Max
3.5
4.2
8.4
16.8
42.0
4.5
5.6
9.8
19.6
49.0
3.6
4.0
7.2
14.4
36.0
0.5
0.5
0.75
1.5
1.5
Min
0.6
0.8
1.5
1.0
0.6
0.8
1.5
1.0
0.6
0.8
1.5
1.0
Units
Figure
Number
Figures
1, 2
ns
Figures
5, 6
Figures
1, 3, 4
ns
Figures
5, 7, 8
Figures
1, 3, 4
ns
Figures
5, 7, 8
15 pF, R
L
30 pF, R
L
2k
:
500
:
1.5
r
0.1
1.2
3.3
r
0.3
2.5
r
0.2
1.8
r
0.15
Output Enable Time
C
L
15 pF, R
L
30 pF, R
L
2k
:
500
:
1.5
r
0.1
1.2
3.3
r
0.3
2.5
r
0.2
1.8
r
0.15
Output Disable Time
C
L
15 pF, R
L
30 pF, R
L
2k
:
500
:
1.5
r
0.1
1.2
3.3
r
0.3
2.5
r
0.2
1.8
r
0.15
C
L
ns
15 pF, R
L
2k
:
1.5
r
0.1
1.2
50 pF, add approximately 300 ps to the AC maximum specification.
Note 7:
Skew is defined as the absolute value of the difference between the actual propagation delay for any two separate outputs of the same device. The
specification applies to any outputs switching in the same direction, either HIGH-to-LOW (t
OSHL
) or LOW-to-HIGH (t
OSLH
).
Dynamic Switching Characteristics
Symbol
V
OLP
Parameter
Quiet Output Dynamic Peak V
OL
C
L
30 pF, V
IH
Conditions
V
CC
, V
IL
0V
V
CC
(V)
1.8
2.5
3.3
V
OLV
Quiet Output Dynamic Valley V
OL
C
L
30 pF, V
IH
V
CC
, V
IL
0V
1.8
2.5
3.3
V
OHV
Quiet Output Dynamic Valley V
OH
C
L
30 pF, V
IH
V
CC
, V
IL
0V
1.8
2.5
3.3
T
A
25
q
C
0.3
0.7
1.0
V
Typical
Units
0.3
0.7
1.0
1.3
1.7
2.0
V
V
Capacitance
Symbol
C
IN
C
I/O
C
PD
Input Capacitance
Input/Output Capacitance
Power Dissipation Capacitance
Parameter
V
I
V
I
V
I
0V or V
CC
, V
CC
0V or V
CC
, V
CC
0V or V
CC
, f
Conditions
1.8V, 2.5V or 3.3V
1.8V, 2.5V or 3.3V
1.8V, 2.5V or 3.3V
T
A
25
q
C
6
7
20
Typical
Units
pF
pF
pF
10 MHz, V
CC
5
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