Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLogic ICsLogic IC - Receiver, transceiver SOIC 24

SN54HCT646, SN74HCT646

OCTAL BUS TRANSCEIVERS AND REGISTERS

WITH 3-STATE OUTPUTS

SCLS178C – MARCH 1984 – REVISED MARCH 2003

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Operating Voltage Range of 4.5 V to 5.5 V

Low Power Consumption, 80-µA Max I

Typical t

= 12 ns

±6-mA Output Drive at 5 V

Low Input Current of 1 µA Max

Inputs Are TTL-Voltage Compatible

Independent Registers for A and B Buses

Multiplexed Real-Time and Stored Data

True Data Paths

High-Current 3-State Outputs Can Drive Up

To 15 LSTTL Loads

14 15 16 17

SN54HCT646 ...JT OR W PACKAGE

SN74HCT646 . . . DW OR NT PACKAGE

(TOP VIEW)

SN54HCT646 . . . FK PACKAGE

(TOP VIEW)

CLKAB

SAB

DIR

GND

CLKBA

SBA

4321 28

12 13

DIR

SAB

CLKAB

GND

CLKBA

SBA

27 26

NC – No internal connection

description/ordering information

The ’HCT646 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 ’HCT646 devices.

Output-enable (OE

) and direction-control (DIR) inputs control the transceiver functions. In the transceiver

mode, data present at the high-impedance port can be stored in either or both registers.

ORDERING INFORMATION

PACKAGE

†

ORDERABLE

PART NUMBER

TOP-SIDE

MARKING

PDIP – NT Tube SN74HCT646NT SN74HCT646NT

–40°C to 85°C

SOIC DW

Tube SN74HCT646DW

HCT646

SOIC

–

Tape and reel SN74HCT646DWR

HCT646

CDIP – JT Tube SNJ54HCT646JT SNJ54HCT646JT

–55°C to 125°C

CFP – W Tube SNJ54HCT646W SNJ54HCT646W

LCCC – FK Tube SNJ54HCT646FK SNJ54HCT646FK

†

Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are

available at www.ti.com/sc/package.

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.

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.

Summary of content (13 pages)

PAGE 1
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 D D D D Operating Voltage Range of 4.5 V to 5.5 V Low Power Consumption, 80-µA Max ICC Typical tpd = 12 ns ±6-mA Output Drive at 5 V Low Input Current of 1 µA Max Inputs Are TTL-Voltage Compatible Independent Registers for A and B Buses Multiplexed Real-Time and Stored Data True Data Paths High-Current 3-State Outputs Can Drive Up To 15 LSTTL Loads SN54HCT646 . . .
PAGE 2
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 description/ordering information (continued) 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 can be stored in one register and /or B data can be stored in the other register.
PAGE 3
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS 21 OE L 3 DIR L 1 23 CLKAB CLKBA X X 2 SAB X BUS B BUS A BUS A BUS B SCLS178C – MARCH 1984 – REVISED MARCH 2003 22 SBA L 21 OE L 3 DIR H 3 DIR X X X 1 23 CLKAB CLKBA X ↑ X ↑ ↑ ↑ 2 SAB X X X 2 SAB L 22 SBA X BUS B BUS A BUS A 21 OE X X H 23 CLKBA X REAL-TIME TRANSFER BUS A TO BUS B BUS B REAL-TIME TRANSFER BUS B TO BUS A 1 CLKAB X 22 SBA X X X STORAGE FROM A, B, OR A AND B 21 OE L L 3 DIR L H 1 CLKA
PAGE 4
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 logic diagram (positive logic) OE DIR CLKBA SBA CLKAB SAB 21 3 23 22 1 2 One of Eight Channels 1D C1 A1 4 20 B1 1D C1 To Seven Other Channels Pin numbers shown are for the DW, JT, NT, and W packages. absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 5
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 recommended operating conditions (see Note 4) SN54HCT646 NOM MAX MIN NOM MAX 4.5 5 5.5 4.5 5 5.5 VCC VIH Supply voltage VIL VI Low-level input voltage Input voltage 0 VO tt Output voltage 0 High-level input voltage VCC = 4.5 V to 5.5 V VCC = 4.5 V to 5.5 V SN74HCT646 MIN 2 2 Input transition (rise and fall) time V V 0.8 VCC VCC UNIT 0 0 500 0.
PAGE 6
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 switching characteristics over recommended operating free-air temperature range, CL = 50 pF (unless otherwise noted) (see Figure 2) PARAMETER FROM (INPUT) TO (OUTPUT) fmax CLKBA or CLKAB tpd d A or B A or B B or A SBA or SAB† A or B ten OE A or B tdis di OE A or B ten DIR A or B tdis di DIR A or B tt Any VCC MIN TA = 25°C TYP MAX SN54HCT646 MIN MAX SN74HCT6
PAGE 7
SN54HCT646, SN74HCT646 OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS SCLS178C – MARCH 1984 – REVISED MARCH 2003 PARAMETER MEASUREMENT INFORMATION VCC S1 Test Point From Output Under Test PARAMETER ten RL tdis CL (see Note A) S2 tPZH RL 1 kΩ tPZL tPHZ 1 kΩ CL S1 S2 50 pF or 150 pF Open Closed Closed Open Open Closed Closed Open Open Open 50 pF tPLZ tpd or tt 50 pF or 150 pF –– LOAD CIRCUIT 3V High-Level Pulse 1.3 V 3V Reference Input 1.3 V 0V 1.
PAGE 8
PACKAGE OPTION ADDENDUM www.ti.
PAGE 9
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device SN74HCT646DWR Package Package Pins Type Drawing SOIC DW 24 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 24.4 Pack Materials-Page 1 10.75 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 15.7 2.7 12.0 24.
PAGE 10
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) SN74HCT646DWR SOIC DW 24 2000 367.0 367.0 45.
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