SN54HC646 Datasheet | Texas Instruments

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 ICC D Typical tpd = 11 ns D ±6-m A 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) DIR SAB CLKAB NC VCC CLKBA SBA CLKAB SAB DIR A1 A2 A3 A4 A5 A6 A7 A8 GND 1 2 3 4 5 6 7 8 9 10 11 12 24 VCC 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 A2 6 A3 7 NC 8 A4 9 A5 10 A6 1112 13 14 15 16 17 1819 OE B1 B2 NC B3 B4 B5 A7 A8 GND NC B8 B7 B6 description/ordering information - 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...