Revised April 2005
74VCXH245
Low Voltage Bidirectional Transceiver with Bushold
General Description
Features
The VCXH245 contains eight non-inverting bidirectional
buffers with 3-STATE outputs and is intended for bus oriented 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 floating data inputs at a valid logic level.
■ 1.2V to 3.6V VCC supply operation
The 74VCXH245 is designed for low voltage (1.2V to 3.6V)
VCC applications.
The 74VCXH245 is fabricated with an advanced CMOS
technology to achieve high-speed operation while maintaining low CMOS power dissipation.
■ Bushold on data inputs eliminates the need for external
pull-up/pull-down resistors
■ tPD
3.5 ns max for 3.0V to 3.6V VCC
■ Static Drive (IOH/IOL)
r24 mA @ 3.0V VCC
■ Uses patented Quiet Series¥ noise/EMI reduction
circuitry
■ Latchup performance exceeds 300 mA
■ ESD performance:
Human body model ! 2000V
Machine model ! 200V
Ordering Code:
Order Number
Package Number
74VCXH245WM
M20B
74VCXH245MTC
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
Description
OE
Output Enable Input (Active LOW)
T/R
Transmit/Receive Input
A0–A7
Side A Bushold Inputs or 3-STATE Outputs
B0–B7
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 Low Voltage Bidirectional Transceiver with Bushold
June 1999
74VCXH245
Connection Diagram
Truth Table
Inputs
Outputs
OE
T/R
L
L
Bus B0–B7 Data to Bus A0–A7
L
H
Bus A0–A7 Data to Bus B0–B7
H
X
HIGH Z State on A0–A7, B0–B7
H HIGH Voltage Level
L LOW Voltage Level
X Immaterial
Z High Impedance
Logic Diagram
www.fairchildsemi.com
2
Recommended Operating
Conditions (Note 3)
0.5V to 4.6V
0.5V to 4.6V
Supply Voltage (VCC)
DC Input Voltage (VI)
Power Supply
DC Output Voltage (VO)
0.5V to 4.6V
0.5V to VCC 0.5V
Outputs Active (Note 2)
DC Input Diode Current (IIK) VI 0V
50 mA
Outputs 3-STATE
50 mA
50 mA
VO ! VCC
(IOH/IOL)
Storage Temperature (TSTG)
Output in Active States
0V to VCC
Output in 3-STATE
0V to 3.6V
Output Current in IOH/IOL
DC Output Source/Sink Current
DC VCC or Ground Current
1.2V to 3.6V
0.3V to 3.6V
Output Voltage (VO)
DC Output Diode Current (IOK)
VO 0V
Operating
Input Voltage
r50 mA
r100 mA
65qC to 150qC
VCC
3.0V to 3.6V
VCC
2.3V to 2.7V
VCC
1.65V to 2.3V
VCC
1.4V to 1.65V
VCC
1.2V
Free Air Operating Temperature (TA)
r24 mA
r18 mA
r6 mA
r2 mA
r100 PA
40qC to 85qC
Minimum Input Edge Rate ('t/'V)
VIN
0.8V to 2.0V, VCC
3.0V
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 Ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation.
Note 2: IO Absolute Maximum Rating must be observed.
Note 3: Floating or unused control inputs must be held HIGH or LOW.
DC Electrical Characteristics
Symbol
Parameter
Conditions
VCC
Min
Max
Units
(V)
VIH
VIL
HIGH Level Input Voltage
2.7 - 3.6
LOW Level Input Voltage
2.0
2.3 - 2.7
1.6
1.65 - 2.3
0.65 x VCC
1.4 - 1.6
0.65 x VCC
1.2
0.65 x VCC
2.7 - 3.6
0.8
2.3 - 2.7
0.7
1.65 - 2.3
0.35 x VCC
1.4 - 1.6
0.35 x VCC
1.2
VOH
HIGH Level Output Voltage
V
0.05 x VCC
IOH
100 PA
2.7 - 3.6
VCC - 0.2
IOH
12 mA
2.7
2.2
IOH
18 mA
3.0
2.4
IOH
24 mA
3.0
2.2
IOH
100 PA
2.3 - 2.7
VCC - 0.2
IOH
6 mA
2.3
2.0
IOH
12 mA
2.3
1.8
IOH
18 mA
2.3
1.7
1.65 - 2.3
VCC - 0.2
IOH
100 PA
IOH
6 mA
IOH
100 PA
IOH
2 mA
1.4
1.05
IOH
100 PA
1.2
VCC - 0.2
3
V
1.65
1.25
1.4 - 1.6
VCC - 0.2
V
www.fairchildsemi.com
74VCXH245
Absolute Maximum Ratings(Note 1)
74VCXH245
DC Electrical Characteristics
Symbol
(Continued)
Parameter
Conditions
VCC
Min
Max
Units
(V)
VOL
LOW Level Output Voltage
IOL
100 PA
2.7 - 3.6
0.2
IOL
12 mA
2.7
0.4
IOL
18 mA
3.0
0.4
IOL
24 mA
3.0
0.55
IOL
100 PA
2.3 - 2.7
0.2
IOL
12 mA
2.3
0.4
IOL
18 mA
2.3
0.6
IOL
100 PA
1.65 - 2.3
0.2
IOL
6 mA
1.65
0.3
IOL
100 PA
IOL
2 mA
1.4 - 1.6
0.2
1.4
0.35
IOL
100 PA
II
Input Leakage Current
VIN
VCC or GND
II(HOLD)
Bushold Input Minimum
VIN
0.8V
3.0
75.0
Drive Hold Current
VIN
2.0V
3.0
75.0
VIN
0.7V
2.3
45.0
VIN
1.6V
2.3
45.0
VIN
0.57V
1.65
25.0
VIN
1.07V
1.65
25.0
II(OD)
IOZ
1.2
0.05
1.2 - 3.6
r5.0
Bushold Input Over-Drive
(Note 4)
3.6
450
Current to Change State
(Note 5)
3.6
450
(Note 4)
2.7
300
(Note 5)
2.7
300
(Note 4)
1.95
200
(Note 5)
1.95
200
3-STATE Output Leakage
VO
VCC or GND
Quiescent Supply Current
VI
Increase in ICC per Input
VIH
PA
PA
VCC or GND
1.2 - 3.6
20.0
PA
VCC 0.6V
2.7 - 3.6
750
PA
Note 4: An external driver must source at least the specified current to switch from LOW-to-HIGH.
Note 5: An external driver must sink at least the specified current to switch from HIGH-to-LOW.
www.fairchildsemi.com
PA
r10.0
VIH or VIL
ICC
PA
1.2 - 3.6
VI
'ICC
V
4
Symbol
Parameter
tPHL,
Propagation Delay
tPLH
An to Bn or Bn to An
VCC
Conditions
CL
CL
30 pF, RL
15 pF, RL
500:
2k:
TA
40qC to 85qC
(V)
Min
Max
3.3 r 0.3
0.6
3.5
2.5 r 0.2
0.8
4.2
1.8 r 0.15
1.5
8.4
1.5 r 0.1
1.0
1.2
tPZL,
Output Enable Time
CL
30 pF, RL
500:
tPZH
CL
15 pF, RL
2k:
Output Disable Time
CL
30 pF, RL
500:
tPHZ
CL
tOSHL
Output to Output Skew
tOSLH
(Note 7)
CL
CL
Note 6: For CL
15 pF, RL
30 pF, RL
15 pF, RL
2k:
500:
2k:
Figures
1, 2
16.8
3.3 r 0.3
0.6
4.5
2.5 r 0.2
0.8
5.6
1.8 r 0.15
1.5
9.8
1.5 r 0.1
1.0
19.6
Figures
5, 6
Figures
1, 3, 4
ns
Figures
5, 7, 8
49.0
3.3 r 0.3
0.6
2.5 r 0.2
0.8
4.0
1.8 r 0.15
1.5
7.2
1.5 r 0.1
1.0
Figure
Number
ns
42.0
1.2
tPLZ,
Units
3.6
Figures
1, 3, 4
ns
14.4
1.2
36.0
3.3 r 0.3
0.5
2.5 r 0.2
0.5
1.8 r 0.15
0.75
1.5 r 0.1
1.5
1.2
1.5
Figures
5, 7, 8
ns
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 (tOSHL) or LOW-to-HIGH (tOSLH).
Dynamic Switching Characteristics
Symbol
VOLP
VOLV
VOHV
Parameter
Quiet Output Dynamic Peak VOL
Quiet Output Dynamic Valley VOL
Quiet Output Dynamic Valley VOH
VCC
Conditions
CL
CL
CL
30 pF, VIH
30 pF, VIH
30 pF, VIH
VCC, VIL
0V
VCC, V IL
VCC, V IL
0V
0V
TA
25qC
(V)
Typical
1.8
0.3
2.5
0.7
3.3
1.0
1.8
0.3
2.5
0.7
3.3
1.0
1.8
1.3
2.5
1.7
3.3
2.0
Units
V
V
V
Capacitance
Symbol
Parameter
TA
Conditions
25qC
Typical
Units
CIN
Input Capacitance
VI
0V or VCC, VCC
1.8V, 2.5V or 3.3V
6
pF
CI/O
Input/Output Capacitance
VI
0V or VCC, VCC
1.8V, 2.5V or 3.3V
7
pF
CPD
Power Dissipation Capacitance
VI
0V or VCC, f
20
pF
5
10 MHz, VCC
1.8V, 2.5V or 3.3V
www.fairchildsemi.com
74VCXH245
AC Electrical Characteristics (Note 6)
74VCXH245
AC Loading and Waveforms (VCC 3.3V r 0.3V to 1.8V r 0.5V)
FIGURE 1. AC Test Circuit
TEST
SWITCH
tPLH, tPHL
Open
tPZL, tPLZ
6V at VCC
VCC x 2 at VCC
tPZH, tPHZ
3.3 r 0.3V;
2.5V r 0.2V; 1.8V r 0.15V
GND
FIGURE 2. Waveform for Inverting and Non-inverting Functions
FIGURE 3. 3-STATE Output High Enable and Disable Times for Low Voltage Logic
FIGURE 4. 3-STATE Output Low Enable and Disable Times for Low Voltage Logic
Symbol
www.fairchildsemi.com
VCC
3.3V r 0.3V
2.5V r 0.2V
1.8V r 0.15V
Vmi
1.5V
VCC /2
VCC /2
Vmo
1.5V
VCC /2
VCC /2
Vx
VOL 0.3V
VOL 0.15V
VOL 0.15V
Vy
VOH 0.3V
VOH 0.15V
VOH 0.15V
6
74VCXH245
AC Loading and Waveforms (VCC 1.5V r 0.1V to 1.2V)
FIGURE 5. AC Test Circuit
TEST
SWITCH
tPLH, tPHL
Open
tPZL, tPLZ
VCC x 2 at VCC
tPZH, tPHZ
1.5 r 0.1V
GND
FIGURE 6. Waveform for Inverting and Non-Inverting Functions
FIGURE 7. 3-STATE Output High Enable and Disable Times for Low voltage Logic
FIGURE 8. 3-STATE Output Low Enable and Disable Times for Low Voltage Logic
VCC
Symbol
1.5V r 0.1V
VCC/2
Vmi
Vmo
VCC/2
VX
VOL 0.1V
VY
VOH 0.1V
7
www.fairchildsemi.com
74VCXH245
Physical Dimensions inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit, JEDEC MS-013, 0.300” Wide Body
Package Number M20B
www.fairchildsemi.com
8
74VCXH245 Low Voltage Bidirectional Transceiver with Bushold
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Thin Shrink Small Outline Package, JEDEC MO-153, 4.4mm Wide
Package Number MTC20
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
www.fairchildsemi.com
9
www.fairchildsemi.com