74LCX245 — Low Voltage Bidirectional Transceiver with 5V Tolerant Inputs and Outputs
February 2008
74LCX245
Low Voltage Bidirectional Transceiver with 5V Tolerant
Inputs and Outputs
Features
■
5V tolerant inputs and outputs
■
2.3V to 3.6V V
CC
specifications provided
■
7.0ns t
PD
max. (V
CC
=
3.3V), 10µA I
CC
max.
■
Power down high impedance inputs and outputs
■
Supports live insertion/withdrawal
(1)
■
±24mA output drive (V
CC
=
3.0V)
■
Implements patented noise/EMI reduction circuitry
■
Latch-up performance exceeds 500mA
■
ESD performance:
General Description
The LCX245 contains eight non-inverting bidirectional
buffers with 3-STATE outputs and is intended for bus
oriented applications. The device is designed for low
voltage (2.5V and 3.3V) V
CC
applications with capability
of interfacing to a 5V signal environment. The T/R input
determines the direction of data flow through the device.
The OE input disables both the A and B ports by placing
them in a high impedance state.
The LCX245 is fabricated with an advanced CMOS tech-
nology to achieve high speed operation while maintain-
ing CMOS low power dissipation.
– Human body model
>
2000V
– Machine model
>
200V
■
Leadless DQFN package
Note:
1. To ensure the high-impedance state during power up
or down, OE should be tied to V
CC
through a pull-up
resistor: the minimum value or the resistor is
determined by the current-sourcing capability of the
driver.
Ordering Information
Order Number
74LCX245WM
74LCX245SJ
74LCX245BQX
(2)
74LCX245MSA
74LCX245MTC
Package
Number
M20B
M20D
MLP20B
MSA20
MTC20
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
20-Terminal Depopulated Quad Very-Thin Flat Pack No Leads (DQFN),
JEDEC MO-241, 2.5 x 4.5mm
20-Lead Shrink Small Outline Package (SSOP), JEDEC MO-150, 5.3mm Wide
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153,
4.4mm Wide
Note:
2. DQFN package available in Tape and Reel only.
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering number.
All packages are lead free per JEDEC: J-STD-020B standard.
©1994 Fairchild Semiconductor Corporation
74LCX245 Rev. 1.11.0
www.fairchildsemi.com
74LCX245 — Low Voltage Bidirectional Transceiver with 5V Tolerant Inputs and Outputs
Connection Diagrams
Pin Assignments for SOIC, SOP, SSOP, and TSSOP
Logic Symbol
Truth Table
Inputs
OE
L
L
Pin Assignment for DQFN
H
T/R
L
H
X
Outputs
Bus B
0
– B
7
Data to Bus A
0
– A
7
Bus A
0
– A
7
Data to Bus B
0
– B
7
HIGH Z State on A
0
– A
7
, B
0
– B
7(3)
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Z
=
High Impedance
Note:
3. Unused bus terminals during HIGH Z State must be
held HIGH or LOW.
Logic Diagram
(Top Through View)
Pin Description
Pin
Names
OE
T/R
A
0
–A
7
B
0
–B
7
Description
Output Enable Input
Transmit/Receive Input
Side A Inputs or 3-STATE Outputs
Side B Inputs or 3-STATE Outputs
©1994 Fairchild Semiconductor Corporation
74LCX245 Rev. 1.11.0
www.fairchildsemi.com
2
74LCX245 — Low Voltage Bidirectional Transceiver with 5V Tolerant Inputs and Outputs
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol
V
CC
V
I
V
O
Supply Voltage
DC Input Voltage
DC Output Voltage
Output in 3-STATE
Parameter
Rating
–0.5V to +7.0V
–0.5V to +7.0V
–0.5V to +7.0V
–0.5V to V
CC
+ 0.5V
–50mA
–50mA
+50mA
±50mA
±100mA
±100mA
–65°C to +150°C
Output in HIGH or LOW State
(4)
I
IK
I
OK
DC Input Diode Current, V
I
<
GND
DC Output Diode Current
V
O
<
GND
V
O
>
V
CC
I
O
I
CC
I
GND
T
STG
DC Output Source/Sink Current
DC Supply Current per Supply Pin
DC Ground Current per Ground Pin
Storage Temperature
Note:
4. I
O
Absolute Maximum Rating must be observed.
Recommended Operating Conditions
(5)
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to absolute maximum ratings.
Symbol
V
CC
Supply Voltage
Operating
Data Retention
V
I
V
O
Input Voltage
Output Voltage
3-STATE
HIGH or LOW State
I
OH
/ I
OL
Output Current
V
CC
=
3.0V–3.6V
V
CC
=
2.7V–3.0V
V
CC
=
2.3V–2.7V
T
A
∆
t /
∆
V
Parameter
Min.
2.0
1.5
0
0
0
Max.
3.6
3.6
5.5
5.5
V
CC
±24
±12
±8
Units
V
V
V
mA
Free-Air Operating Temperature
Input Edge Rate, V
IN
=
0.8V–2.0V, V
CC
=
3.0V
–40
0
85
10
°C
ns / V
Note:
5. Unused inputs must be held HIGH or LOW. They may not float.
©1994 Fairchild Semiconductor Corporation
74LCX245 Rev. 1.11.0
www.fairchildsemi.com
3
74LCX245 — Low Voltage Bidirectional Transceiver with 5V Tolerant Inputs and Outputs
DC Electrical Characteristics
T
A
=
–40°C to +85°C
Symbol
V
IH
V
IL
V
OH
Parameter
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Voltage
V
CC
(V)
2.3–2.7
2.7–3.6
2.3–2.7
2.7–3.6
2.3–3.6
2.3
2.7
3.0
Conditions
Min.
1.7
2.0
Max.
Units
V
0.7
0.8
I
OH
=
–100µA
I
OH
=
–8mA
I
OH
=
–12mA
I
OH
=
–18mA
I
OH
=
–24mA
I
OL
=
100µA
I
OL
=
8mA
I
OL
=
12mA
I
OL
=
16mA
I
OL
=
24mA
0
≤
V
I
≤
5.5V
0
≤
V
O
≤
5.5V,
V
I
= V
IH
or V
IL
V
I
or V
O
=
5.5V
V
I
=
V
CC
or GND
3.6V
≤
V
I
, V
O
≤
5.5V
(6)
V
IH
=
V
CC
– 0.6V
V
CC
– 0.2
1.8
2.2
2.4
2.2
0.2
0.6
0.4
0.4
0.55
±5.0
±5.0
10
10
±10
500
V
V
V
OL
LOW Level Output Voltage
2.3–3.6
2.3
2.7
3.0
V
I
I
I
OZ
I
OFF
I
CC
∆I
CC
Input Leakage Current
3-STATE Output Leakage
Power-Off Leakage Current
Quiescent Supply Current
Increase in I
CC
per Input
2.3–3.6
2.3–3.6
0
2.3–3.6
2.3–3.6
µA
µA
µA
µA
µA
Note:
6. Outputs disabled or 3-STATE only.
AC Electrical Characteristics
T
A
=
–40°C to +85°C, R
L
=
500Ω
V
CC
=
3.3V ± 0.3V,
C
L
=
50pF
Symbol
t
PHL
, t
PLH
t
PZL
, t
PZH
t
PLZ
, t
PHZ
t
OSHL
, t
OSLH
V
CC
=
2.7V,
C
L
=
50pF
Min.
1.5
1.5
1.5
V
CC
=
2.5V ± 0.2V,
C
L
=
30pF
Min.
1.5
1.5
1.5
Parameter
Propagation Delay,
A
n
to B
n
or B
n
to A
n
Output Enable Time
Output Disable Time
Output to Output Skew
(7)
Min.
1.5
1.5
1.5
Max.
7.0
8.5
7.5
1.0
Max.
8.0
9.5
8.5
Max.
8.4
10.5
9.0
Units
ns
ns
ns
ns
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
).
©1994 Fairchild Semiconductor Corporation
74LCX245 Rev. 1.11.0
www.fairchildsemi.com
4
74LCX245 — Low Voltage Bidirectional Transceiver with 5V Tolerant Inputs and Outputs
Dynamic Switching Characteristics
T
A
=
25°C
Symbol
V
OLP
V
OLV
Parameter
Quiet Output Dynamic Peak V
OL
Quiet Output Dynamic Valley V
OL
V
CC
(V)
3.3
2.5
3.3
2.5
Conditions
C
L
=
50pF, V
IH
=
3.3V, V
IL
=
0V
C
L
=
30pF, V
IH
=
2.5V, V
IL
=
0V
C
L
=
50pF, V
IH
=
3.3V, V
IL
=
0V
C
L
=
30pF, V
IH
=
2.5V, V
IL
=
0V
Typical
0.8
0.6
–0.8
–0.6
Unit
V
V
Capacitance
Symbol
C
IN
C
OUT
C
PD
Parameter
Input Capacitance
Output Capacitance
Power Dissipation Capacitance
Conditions
V
CC
=
Open, V
I
=
0V or V
CC
V
CC
=
3.3V, V
I
=
0V or V
CC
V
CC
=
3.3V, V
I
=
0V or V
CC
, f
=
10MHz
Typical
7.0
8.0
25.0
Units
pF
pF
pF
©1994 Fairchild Semiconductor Corporation
74LCX245 Rev. 1.11.0
www.fairchildsemi.com
5
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