DM74ALS652WM

© 2001 Fairchild Semiconductor Corporation DS009174 www.fairchildsemi.com
October 1986
Revised June 2001
DM74ALS652 Octal 3-STATE Bus Transceiver and Register
DM74ALS652
Octal 3-STATE Bus Transceiver and Register
General Description
This device incorporates an octal transceiver and an octal
D-type register configured to enable transmission of data
from bus to bus or internal register to bus.
This bus transceiver features totem-pole 3-STATE outputs
designed specifically for driving highly-capacitive or rela-
tively low-impedance loads. The high-impedance state and
increased high level logic drive provide this device with the
capability of being connected directly to and driving the bus
lines in a bus organized system without need for interface
or pull-up components. They are particularly attractive for
implementing buffer registers, I/O ports, bidirectional bus
drivers, and working registers.
The registers in the DM74ALS652 are edge-triggered
D-type flip-flops. On the positive transition of the clock
(CAB or CBA), the input data is stored into the appropriate
register. The CAB input controls the transfer of data into
the A register and the CBA input controls the B register.
The SAB and SBA control pins are provided to select
whether real-time data or stored data is transferred. A LOW
input level selects real-time data and a HIGH level selects
stored data. The select controls have a “make before
break” configuration to eliminate a glitch which would nor-
mally occur in a typical multiplexer during the transition
between stored and real-time data.
The enable (GAB and G
BA) control pins provide four
modes of operation: real-time data transfer from bus A to
B, real-time data transfer from bus B to A, real-time bus A
and/or B data transfer to internal storage, or internal stored
data transfer to bus A and/or B.
Features
Switching specifications at 50 pF
Switching specifications guaranteed over full tempera-
ture and V
CC
range
Advanced oxide-isolated, ion-implanted Schottky TTL
process
3-STATE buffer-type outputs drive bus lines directly
Independent registers and enables for A and B buses
Multiplexed real-time and stored data
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter X to the ordering code.
Connection Diagram
Order Number Package Number Package Description
DM74ALS652WM M24B 24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
DM74ALS652NT N24C 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
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DM74ALS652
Function Table
H = HIGH Logic Level
L = LOW Logic Level
X = Dont Care (Either LOW or HIGH Logic Levels, including transitions)
H/L = Either LOW or HIGH Logic Level excluding transitions
= Positive-going edge of pulse
Note 1: The data output functions may be enabled or disabled by various signals at the G
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 on the clock inputs.
Note 2: Select control = L; clocks can occur simultaneously
Select control = H; clocks must be staggered in order to load both registers.
Logic Diagram
Inputs Data I/O (Note 1)
Operation or Function
GAB G
BA CAB CBA SAB SBA A1 thru A8 B1 thru B8
XH
H/L X X Input Not Specified Store A, Hold B
LXH/L
X X Not Specified Input Store B, Hold A
LH
↑↑X X Input Input Store A and B Data
L H H/L H/L X X Input Input Isolation, Hold Storage
L L X X X L Output Input Real-Time B Data to A Bus
L L X H/L X H Output Input Stored B Data to A Bus
H H X X L X Input Output Real-Time A Data to B Bus
HH
↑↑X X Input Output Stored A Data to B Bus
HH
↑↑X
(Note 2)
X Input Output Store A in both Registers
LL
↑↑XX
(Note 2)
Output Input Store B in both Registers
H L H or L H or L H H Output Output Stored A Data to B Bus and
Stored B Data to A Bus
3 www.fairchildsemi.com
DM74ALS652
Absolute Maximum Ratings(Note 3)
Note 3: 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.
Recommended Operating Conditions
Note 4: = with reference to the LOW-to-HIGH transition of the respective clock.
Electrical Characteristics
over recommended free air temperature range
Note 5: For I/O ports the 3-STATE output currents (I
OZH
and I
OZL
) are included in the I
IH
and I
IL
parameters.
Supply Voltage 7V
Input Voltage
Control Inputs 7V
I/O Ports 5.5V
Operating Free-Air Temperature Range 0
°C to +70°C
Storage Temperature Range
65°C to +150°C
Typical
θ
JA
N Package 44.5°C/W
M Package 80.5
°C/W
Symbol Parameter Min Nom Max Units
V
CC
Supply Voltage 4.5 5 5.5 V
V
IH
HIGH Level Input Voltage 2 V
V
IL
LOW Level Input Voltage 0.8 V
I
OH
HIGH Level Output Current 15 mA
I
OL
LOW Level Output Current 24 mA
f
CLK
Clock Frequency 0 40 MHz
t
W
Pulse Duration, Clocks LOW or HIGH 12.5 ns
t
SU
Data Setup Time, A before CAB or 10 ns
B before CBA (Note 4)
t
H
Data Hold Time, A after CAB or 0 ns
B after CBA (Note 4)
T
A
Free Air Operating Temperature 0 70 °C
Symbol Parameter Test Conditions Min Typ Max Units
V
IK
Input Clamp Voltage V
CC
= Min, I
I
= 18 mA 1.2 V
V
OH
HIGH Level V
CC
= 4.5V to 5.5V I
OH
= 0.4 mA V
CC
2
Output Voltage V
CC
= Min I
OH
= 3 mA 2.4 3.2 V
I
OH
= Max 2
V
OL
LOW Level V
CC
= Min I
OL
= 12 mA 0.25 0.4
Output Voltage I
OL
= 24 mA 0.35 0.5 V
I
OL
= 48 mA 0.35 0.5
I
I
Input Current at Maximum V
CC
= Max I/O Ports, V
I
= 5.5V 100
µA
Input Voltage Control Inputs, V
I
= 7V 100
I
IH
HIGH Level Input Current V
CC
= Max, V
I
= 2.7V, (Note 5) 20 µA
I
IL
LOW Level V
CC
= Max, Control Inputs 200
µA
Input Current V
I
= 0.4V (Note 5) I/O Ports 200
I
O
Output Drive Current V
CC
= Max, V
O
= 2.25V 30 112 mA
I
CC
Supply Current V
CC
= Max Outputs HIGH 47 76
Outputs LOW 55 88 mA
Outputs Disabled 55 88

DM74ALS652WM

Mfr. #:
Manufacturer:
ON Semiconductor / Fairchild
Description:
Bus Transceivers Oct 3-STATE Tran Reg
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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