SN54HC646_15 Datasheet, PDF (1/16 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

SN54HC646, SN74HC646
OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3-STATE OUTPUTS
SCLS150C – DECEMBER 1982 – REVISED MARCH 2003
D Wide Operating Voltage Range of 2 V to 6 V
D High-Current 3-State Outputs Can Drive Up
To 15 LSTTL Loads
D Low Power Consumption, 80-µA Max I_CC
D Typical t_pd = 11 ns
D ±6-mA Output Drive at 5 V
D Low Input Current of 1 µA Max
D Independent Registers for A and B Buses
D Multiplexed Real-Time and Stored Data
D True Data Paths
SN54HC646 . . . JT OR W PACKAGE
SN74HC646 . . . DW OR NT PACKAGE
(TOP VIEW)
SN54HC646 . . . FK PACKAGE
(TOP VIEW)
CLKAB 1
SAB 2
DIR 3
A1 4
A2 5
A3 6
A4 7
A5 8
A6 9
A7 10
A8 11
GND 12
24 V_CC
23 CLKBA
22 SBA
21 OE
20 B1
19 B2
18 B3
17 B4
16 B5
15 B6
14 B7
13 B8
4 3 2 1 28 27 26
A1 ₅
25 ^OE
A2 ₆
24 B1
A3 7
23 B2
NC 8
22 NC
A4 9
21 B3
A5 10
20 B4
A6 1112 _{13 14 15 16 17 1819} B5
description/ordering information
NC – No internal connection
The ’HC646 devices consist 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 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 ’HC646 devices.
Output-enable (OE) and direction-control (DIR) inputs control the transceiver functions. In the transceiver
mode, data present at the high-impedance port may be stored in either or both registers.
The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. DIR
determines which bus receives data when OE is active (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.
ORDERING INFORMATION
TA
PACKAGE†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
PDIP – NT
Tube
SN74HC646NT
SN74HC646NT
–40°C to 85°C
SOIC – DW
Tube
Tape and reel
SN74HC646DW
SN74HC646DWR
HC646
CDIP – JT
Tube
SNJ54HC646JT
SNJ54HC646JT
–55°C to 125°C CFP – W
Tube
SNJ54HC646W
SNJ54HC646W
LCCC – FK
Tube
SNJ54HC646FK
SNJ54HC646FK
† _{Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are}
available at www.ti.com/sc/package.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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.
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