74AC11648
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS114 – MARCH 1990 – REVISED APRIL 1993
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Independent Registers for A and B Buses
Multiplexed Real-Time and Stored Data
Inverting Data Paths
Flow-Through Architecture Optimizes
PCB Layout
Center-Pin V
CC
and GND Configurations
Minimize High-Speed Switching Noise
EPIC
™
(Enhanced-Performance Implanted
CMOS) 1-µm Process
500-mA Typical Latch-Up Immunity
at 125°C
Package Options Include Plastic
Small-Outline Packages and Standard
Plastic 300-mil DIPs
DW OR NT PACKAGE
(TOP VIEW)
description
OE
A1
A2
A3
A4
GND
GND
GND
GND
A5
A6
A7
A8
DIR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
CLKAB
SAB
B1
B2
B3
B4
V
CC
V
CC
B5
B6
B7
B8
CLKBA
SBA
The 74AC11648 consists of bus transceiver
circuits, D-type flip-flops, and control circuitry
arranged for multiplexed transmission of data
directly from the input bus or from the internal
registers. Data on the A or B bus is clocked into the registers on the low-to-high transition of the appropriate clock
(CLKAB or CLKBA) input. Figure 1 illustrates the four fundamental bus-management functions that can be
performed with the 74AC11648.
Output-enable (OE) and direction-control (DIR) inputs are provided to control the transceiver functions. In the
transceiver mode, data present at the high-impedance port may be stored in either register or in both.
The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The
direction control (DIR) determines which bus will receive data when OE is low. In the isolation mode (OE high),
A data may be stored in one register and/or B data may be stored in the other register.
When an output function is disabled, the input function is still enabled and may be used to store and transmit
data. Only one of the two buses, A or B, may be driven at a time.
The 74AC11648 is characterized for operation from – 40°C to 85°C.
EPIC is a trademark of Texas Instruments Incorporated.
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.
Copyright
©
1993, Texas Instruments Incorporated
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
2–1
74AC11648
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS114 – MARCH 1990 – REVISED APRIL 1993
BUS B
BUS B
28
CLKAB
X
16
CLKBA
X
27
SAB
L
15
SBA
X
REAL-TIME TRANSFER
BUS A TO BUS B
28
CLKAB
X
L
16
CLKBA
L
X
27
SAB
X
H
BUS B
15
SBA
H
X
TRANSFER STORED DATA
TO A AND/OR B
BUS A
1
OE
L
14
DIR
L
16
28
CLKAB CLKBA
X
X
27
SAB
X
15
SBA
L
1
OE
L
REAL-TIME TRANSFER
BUS B TO BUS A
BUS B
BUS A
1
OE
X
X
H
14
DIR
X
X
X
28
16
CLKAB CLKBA
X
↑
X
↑
↑
↑
STORAGE FROM
A, B, OR A AND B
27
SAB
X
X
X
15
SBA
X
X
X
1
OE
L
L
Figure 1. Bus-Management Functions
2–2
POST OFFICE BOX 655303
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DALLAS, TEXAS 75265
BUS A
14
DIR
L
H
BUS A
14
DIR
H
74AC11648
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS114 – MARCH 1990 – REVISED APRIL 1993
FUNCTION TABLE
INPUTS
OE
X
X
H
H
L
L
L
L
DIR
X
X
X
X
L
L
H
H
CLKAB
↑
X
↑
L
X
X
X
L
CLKBA
X
↑
↑
L
X
L
X
X
SAB
X
X
X
X
X
X
L
H
SBA
X
X
X
X
L
H
X
X
DATA I/O
A1 THRU A8
Input
Unspecified†
Input
Input disabled
Output
Output
Input
Input
B1 THRU B8
Unspecified†
Input
Input
Input disabled
Input
Input
Output
Output
OPERATION OR FUNCTION
Store A, B unspecified†
Store B, A unspecified†
Store A and B data
Isolation, hold storage
Real-time B data to A bus
Stored B data to A bus
Real-time A data to B bus
Stored A data to B bus
† The data output functions may be enabled or disabled by various signals at the OE and DIR inputs. Data input functions are always enabled;
i.e., data at the bus pins will be stored on every low-to-high transition of the clock inputs.
logic symbol
‡
1
OE
DIR
CLKBA
SBA
CLKAB
SAB
14
16
15
28
27
C6
G7
≥1
1
6D
1
A2
A3
A4
A5
A6
A7
A8
3
4
5
10
11
12
13
7
7
25
24
23
20
19
18
17
B2
B3
B4
B5
B6
B7
B8
5
5
1
≥1
2
4D
20
B1
G3
3 EN1 [BA]
3 EN2 [AB]
C4
G5
A1
2
‡ This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
2–3
74AC11648
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS114 – MARCH 1990 – REVISED APRIL 1993
logic diagram (positive logic)
OE
1
DIR
CLKBA
SBA
CLKAB
SAB
14
16
15
28
27
1 of Eight
Channels
1D
C1
A1
2
26
1D
C1
B1
To Seven Other Channels
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage range, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V
Input voltage range, V
I
(see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to V
CC
+ 0.5 V
Output voltage range, V
O
(see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to V
CC
+ 0.5 V
Input clamp current, I
IK
(V
I
< 0 or V
I
> V
CC
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
20 mA
Output clamp current, I
OK
(V
O
< 0 or V
O
> V
CC
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
50 mA
Continuous output current, I
O
(V
O
= 0 to V
CC
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
50 mA
Continuous current through V
CC
or GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
200 mA
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 affect device reliability.
NOTE 1: The input and output voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
2–4
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
74AC11648
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS114 – MARCH 1990 – REVISED APRIL 1993
recommended operating conditions
MIN
VCC
VIH
Supply voltage
High-level input voltage
VCC = 3 V
VCC = 4.5 V
VCC = 5.5 V
VCC = 3 V
VIL
VI
VO
IOH
Low-level input voltage
Input voltage
Output voltage
High-level output current
VCC = 3 V
VCC = 4.5 V
VCC = 5.5 V
VCC = 3 V
IOL
∆t
/∆v
TA
Low-level output current
Input transition rise or fall rate
Operating free-air temperature
VCC = 4.5 V
VCC = 5.5 V
0
– 40
VCC = 4.5 V
VCC = 5.5 V
0
0
3
2.1
3.15
3.85
0.9
1.35
1.65
VCC
VCC
–4
– 24
– 24
12
24
24
10
85
ns/ V
°C
mA
mA
V
V
V
V
NOM
5
MAX
5.5
UNIT
V
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
VCC
3V
IOH = – 50
µA
VOH
IOH = – 4 mA
IOH = – 24 mA
A
IOH = – 75 mA†
IOL = 50
µA
VOL
IOL = 12 mA
IOL = 24 mA
IOL = 75 mA†
VI = VCC or GND
VO = VCC or GND
VI = VCC or GND,
VI = VCC or GND
VO = VCC or GND
IO = 0
4.5 V
5.5 V
3V
4.5 V
5.5 V
5.5 V
3V
4.5 V
5.5 V
3V
4.5 V
5.5 V
5.5 V
5.5 V
5.5 V
5.5 V
5V
5V
4.5
12
±
0.1
±
0.5
8
0.1
0.1
0.1
0.36
0.36
0.36
TA = 25°C
MIN
TYP
MAX
2.9
4.4
5.4
2.58
3.94
4.94
MIN
2.9
4.4
5.4
2.48
3.8
4.8
3.85
0.1
0.1
0.1
0.44
0.44
0.44
1.65
±1
±
5
80
µA
µA
µA
pF
pF
V
V
MAX
UNIT
II
IOZ‡
ICC
Ci
Cio
Control inputs
A or B ports
Control inputs
A or B ports
† Not more than one output should be tested at a time, and the duration of the test should not exceed 10 ms.
‡ For I/O ports, the parameter IOZ includes the input leakage current.
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•
DALLAS, TEXAS 75265
2–5
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