SN54F242, SN74F242
QUADRUPLE BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDFS062A – D2932, MARCH 1987 – REVISED OCTOBER 1993
Copyright 1993, Texas Instruments Incorporated
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
•Asynchronous Communication Between
Data Buses
•Local Bus-Latch Capability
•Inverting Logic
•Package Options Include Plastic
Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs
description
These quadruple bus transceivers are designed
for asynchronous communications between data
buses. The control function implementation allows
for maximum flexibility in timing. These devices
allow data transmission from the A bus to the
B bus or from the B bus to the A bus depending
upon the logic levels at the output-enable (OEBA
and OEAB) inputs. The output-enable inputs can
be used to disable the device so that the buses are
effectively isolated.
The dual-enable configuration gives the
quadruple bus transceivers the capability to store
data by simultaneous enabling of OEBA and
OEAB. Each output reinforces its input in this
transceiver configuration. Thus, when both control
inputs are enabled and all other data sources to
the two sets of bus lines are at high impedance,
both sets of bus lines (eight in all) remain at their
states. The 4-bit codes appearing on the two sets
of buses will be complementary for the ′F242.
The SN54F242 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74F242 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
FUNCTION
OEAB OEBA
FUNCTION
L L A to B
HHB to A
HL Isolation
L H Latch A and B
(A = B)
SN54F242 ...J PACKAGE
SN74F242 ...D OR N PACKAGE
(TOP VIEW)
SN54F242 . . . FK PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
NC
NC
B1
NC
B2
A1
NC
A2
NC
A3
NC
OEAB
NC
B4
B3 V
OEBA
A4
GND
NC CC
NC – No internal connection
1
2
3
4
5
6
7
14
13
12
11
10
9
8
OEAB
NC
A1
A2
A3
A4
GND
VCC
OEBA
NC
B1
B2
B3
B4
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
SN54F242, SN74F242
QUADRUPLE BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDFS062A – D2932, MARCH 1987 – REVISED OCTOBER 1993
2–2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol†
3
A1 B1
11
EN2
1EN1
13
OEBA
5
A3
6
A4
4
A2 B2
10
B3
9
B4
8
OEAB
1
2
†This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
logic diagram (positive logic)
B4
B3
B2
B1
OEBA
8
9
10
11
13
A4
A3
A2
A1
OEAB
6
5
4
3
1
Pin numbers shown are for the D, J, and N packages.
SN54F242, SN74F242
QUADRUPLE BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDFS062A – D2932, MARCH 1987 – REVISED OCTOBER 1993
2–3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, VI (see Note 1) –1.2 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input current range –30 mA to 5 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the disabled or power-off state –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the high state –0.5 V to VCC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current into any output in the low state: SN54F242 96 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F242 128 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range: SN54F242 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F242 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may af fect device reliability.
NOTE 1: The input voltage ratings may be exceeded provided the input current ratings are observed.
recommended operating conditions
SN54F242 SN74F242
UNIT
MIN NOM MAX MIN NOM MAX
UNIT
VCC Supply voltage 4.5 5 5.5 4.5 5 5.5 V
VIH High-level input voltage 2 2 V
VIL Low-level input voltage 0.8 0.8 V
IIK Input clamp current –18 –18 mA
IOH High-level output current –12 –15 mA
IOL Low-level output current 48 64 mA
TAOperating free-air temperature –55 125 0 70 °C
SN54F242, SN74F242
QUADRUPLE BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDFS062A – D2932, MARCH 1987 – REVISED OCTOBER 1993
2–4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN54F242 SN74F242
UNIT
PARAMETER
TEST
CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
VIK VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
IOH = – 3 mA 2.4 3.3 2.4 3.3
VOH
VCC = 4.5 V IOH = – 12 mA 2 3.2
V
V
OH IOH = – 15 mA 2 3.1
V
VCC = 4.75 V, IOH = – 3 mA 2.7
VOL
VCC =45V
IOL = 48 mA 0.38 0.55
V
V
OL
V
CC =
4
.
5
V
IOL = 64 mA 0.42 0.55
V
II
A or B port
VCC =55V
VI = 5.5 V 1 1
mA
I
IControl inputs
V
CC =
5
.
5
V
VI = 7 V 0.1 0.1
mA
IIH
A or B port‡
VCC =55V
VI=27V
70 70
µA
I
IH Control inputs
V
CC =
5
.
5
V
,
V
I =
2
.
7
V
20 20 µ
A
IIL‡VCC = 5.5 V, VI = 0.5 V –1 –1 mA
IOS§VCC = 5.5 V, VO = 0 –100 –225 –100 –225 mA
V55V
Outputs high 30 46 30 46
ICC
V
CC =
5
.
5
V
,
See Note 2
Outputs low 46 69 46 69 mA
See
Note
2
Outputs disabled 42 63 42 63
†All typical values are at VCC = 5 V, TA = 25°C.
‡For I/O ports, the parameters IIH and IIL include the off-state output current.
§Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.
NOTE 2: ICC is measured either with all transceivers enabled in only one direction or all transceivers disabled.
switching characteristics (see Note 3)
PARAMETER FROM
(
INPUT
)
TO
(
OUTPUT
)
VCC = 5 V,
CL = 50 pF,
RL = 500 Ω,
TA = 25°C
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500Ω,
TA = MIN to MAX¶UNIT
(INPUT)
(OUTPUT)
′F242 SN54F242 SN74F242
MIN TYP MAX MIN MAX MIN MAX
tPLH
AorB
BorA
2.2 4.1 6.5 2.2 9 2.2 7.5
ns
tPHL
A
or
B
B
or
A
1 2.6 4.5 0.5 5 1 4.5
ns
tPZL
Enable
AorB
2.7 5.6 7.5 2.2 10 2.7 8.5
ns
tPZH
Enable
A
or
B
2.7 6.1 9 2.2 12 2.7 10.5
ns
tPHZ
Disable
AorB
1.8 6.6 9 1.8 11 1.8 9.5
ns
tPLZ
Disable
A
or
B
2.7 5.6 9.5 2.3 13.5 2.7 11
ns
¶For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
NOTE 3: Load circuits and waveforms are shown in Section 1.
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Copyright 1998, Texas Instruments Incorporated
