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INTEGRATED CIRCUITS
74ABT646A
Octal bus transceiver/register (3-State)
Product specification
Supersedes data of 1995 Sep 06
IC23 Data Handbook
1998 Feb 17
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Philips Semiconductors Product specification
74ABT646AOctal bus transceiver/register (3-State)
FEA TURES
•Combines 74ABT245 and 74ABT374 type functions in one device
•Independent registers for A and B buses
•Live insertion/extraction permitted
•Power-up 3-State
•Power-up reset
•Multiplexed real-time and stored data
•Output capability: +64mA/–32mA
•Latch-up protection exceeds 500mA per Jedec Std 17
•ESD protection exceeds 2000 V per MIL STD 883 Method 3015
and 200 V per Machine Model
DESCRIPTION
The 74ABT646A high-performance BiCMOS device combines low
static and dynamic power dissipation with high speed and high
output drive.
QUICK REFERENCE DATA
SYMBOL PARAMETER
t
PLH
t
PHL
C
C
I
CCZ
IN
I/O
Propagation delay
An to Bn or Bn to An
Input capacitance
CP, S, OE, DIR
I/O capacitance
Total supply current Outputs disabled; VCC =5.5V 110 µA
The 74ABT646A transceiver/register consists of bus transceiver
circuits with 3-State outputs, D-type flip-flops, and control circuitry
arranged for multiplexed transmission of data directly from the input
bus or the internal registers. Data on the A or B bus will be clocked
into the registers as the appropriate clock pin goes High. Output
Enable (OE
function. In the transceiver mode, data present at the high
impedance port may be stored in either the A or B register or both.
The Select (SAB, SBA) pins determine whether data is stored or
transferred through the device in real-time. The DIR determines
which bus will receive data when the OE
isolation mode (OE
register and/or data from Bus B may be stored in the A 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 examples on the
next page demonstrate the four fundamental bus management
functions that can be performed with the 74ABT646A.
CONDITIONS
T
= 25°C; GND = 0V
amb
CL = 50pF; VCC = 5V
VI = 0V or V
CC
Outputs disabled;
V
= 0V or V
O
CC
) and DIR pins are provided to control the transceiver
is active (Low). In the
= High), data from Bus A may be stored in the B
TYPICAL UNIT
3.2
3.7
ns
4 pF
7 pF
ORDERING INFORMATION
PACKAGES TEMPERATURE RANGE OUTSIDE NORTH AMERICA NORTH AMERICA DWG NUMBER
24-Pin Plastic DIP –40°C to +85°C 74ABT646A N 74ABT646A N SOT222-1
24-Pin plastic SO –40°C to +85°C 74ABT646A D 74ABT646A D SOT137-1
24-Pin Plastic SSOP Type II –40°C to +85°C 74ABT646A DB 74ABT646A DB SOT340-1
24-Pin Plastic TSSOP Type I –40°C to +85°C 74ABT646A PW 7ABT646APW DH SOT355-1
PIN CONFIGURATION
1
CPAB
2
SAB
3
DIR
4
A0
5
A1
6
A2
7
A3
8
A4
9
A5
10
A6
11
A7
12
GND
V
24
CPBA
23
SBA
22
OE
21
B0
20
B1
19
B2
18
B3
17
B4
16
B5
15
B6
14
B713
SA00082
CC
PIN DESCRIPTION
PIN NUMBER SYMBOL FUNCTION
1, 23
CPAB /
CPBA
2, 22 SAB / SBA
3 DIR Direction control input
4, 5, 6, 7,
8, 9, 10, 11
20, 19, 18, 17,
16, 15, 14, 13
A0 – A7 Data inputs/outputs (A side)
B0 – B7 Data inputs/outputs (B side)
21 OE
12 GND Ground (0V)
24 V
CC
A to B clock input / B to A clock
input
A to B select input / B to A
select input
Output enable input
(active-Low)
Positive supply voltage
1998 Feb 17 853-1553 18978
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Philips Semiconductors Product specification
74ABT646AOctal bus transceiver/register (3-State)
LOGIC SYMBOL
3
23
22 SBA
21 OE
4567 891011
A0 A1 A2 A3 A4 A5 A6 A7
CPAB1
SAB2
DIR
CPBA
B0 B1 B2 B3 B4 B5 B6 B7
20 19 18 17 16 15 14 13
SA00083
LOGIC SYMBOL (IEEE/IEC)
21
3
22
2
23
1
4
5
6
7
8
9
10
11
G3
3EN1 [BA]
3EN2 [AB]
G6
G7
C4
C5
1
1
5D 7
17
64D
1
6
1
2
20
19
18
17
16
15
14
13
SA00084
REAL TIME BUS TRANSFER
BUS B TO BUS A
A
B
}
DIR CPABCPBA SAB SBA
OE
LLXXXL
REAL TIME BUS TRANSFER
BUS A TO BUS B
AAA
BBB
}
DIR CPABCPBA SAB SBA
OE
LHXXLX
STORAGE FROM
A, B, OR A AND B
}
DIR CPABCPBA SAB SBA
OE
LH↑ XXX
LLX↑ XX
HX↑↑XX
TRANSFER STORED DATA
TO A OR B
}
DIR CPABCPBA SAB SBA
OE
L L X H or L X H
L H H or L X H X
SA00085
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Philips Semiconductors Product specification
74ABT646AOctal bus transceiver/register (3-State)
FUNCTION TABLE
INPUTS DATA I/O
OE DIR CPAB CPBA SAB SBA An Bn
X X ↑ X X X Input
X
X
L
H
X
X
Unspecified
output*
Input Input
Output Input
Input Output
X X X ↑ X X
H
H
L
L
L
L
X
X
L
L
H
H
↑
H or L
X
X
X
H or L
↑
H or L
X
H or L
X
X
X
X
X
X
L
H
H = High voltage level
L = Low voltage level
X = Don’t care
↑ = Low-to-High clock transition
* The data output function may be enabled or disabled by various signals at the OE
data at the bus pins will be stored on every Low-to-High transition of the clock.
Unspecified
output*
Store A, B unspecified
Input 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
input. Data input functions are always enabled, i.e.,
LOGIC DIAGRAM
OE
DIR
CPBA
SBA
CPAB
SAB
A0
21
3
23
22
1
2
1of 8 Channels
4
1D
C1
Q
1D
C1
Q
20
B0
1998 Feb 17
5
A1
6
A2
7
A3
8
A4
9
A5
10
A6
11
A7
DETAIL A X 7
19
B1
18
B2
17
B3
16
B4
15
B5
14
B6
13
B7
SA00086
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Philips Semiconductors Product specification
74ABT646AOctal bus transceiver/register (3-State)
ABSOLUTE MAXIMUM RATINGS
SYMBOL
V
CC
I
IK
V
I
I
OK
V
OUT
I
OUT
T
stg
DC supply voltage –0.5 to +7.0 V
DC input diode current VI < 0 –18 mA
DC input voltage
DC output diode current VO < 0 –50 mA
DC output voltage
DC output current output in Low state 128 mA
Storage temperature range –65 to 150 °C
PARAMETER CONDITIONS RATING UNIT
3
3
1, 2
–1.2 to +7.0 V
output in Off or High state –0.5 to +5.5 V
NOTES:
1. Stresses beyond those listed 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 .
2. The performance capability of a high-performance integrated circuit in conjunction with its thermal environment can create junction
temperatures which are detrimental to reliability. The maximum junction temperature of this integrated circuit should not exceed 150°C.
3. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
RECOMMENDED OPERATING CONDITIONS
LIMITS
Min Max
V
CC
V
V
V
I
OH
I
OL
∆t/∆v Input transition rise or fall rate 0 10 ns/V
T
amb
DC supply voltage 4.5 5.5 V
Input voltage 0 V
I
High-level input voltage 2.0 V
IH
Low-level Input voltage 0.8 V
IL
High-level output current –32 mA
Low-level output current 64 mA
Operating free-air temperature range –40 +85 °C
CC
V
1998 Feb 17
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