器件名称: HD74HC674
功能描述: 16-bit Shift Register
文件大小: 44.52KB 共8页
简 介:HD74HC674
16-bit Shift Register
Description
The HD74HC674 is a 16-bit parallel-in, serial-out shift register. A three-state input/output (data I/O) port provides access for entering serial data or reading the shift-register word in a recirculating loop. The device has four basic modes of operation: 1. 2. 3. 4. Hold (do nothing) Write (serially via input/output) Read (serially) Load (parallel via data inputs)
Low-to-high-level changes at the chip select input should be made only when the clock input is low to prevent false clocking.
Features
High Speed Operation: tpd (CLK to SER/Q15) = 17 ns typ (CL = 50 pF) High Output Current: Fanout of 15 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 A max Low Quiescent Supply Current: ICC (static) = 4 A max (Ta = 25°C)
Function Table
Inputs CS H L L L R/W X L H H Mode X X L H CLK X SER/Q15 Z Z Q14n P15 Operation Do nothing Shift and write (serial load) Shift and read Parallel load
HD74HC674
Pin Arrangement
CS CLK R/W NC Mode SER/Q15 P0 P1 P2
1 2 3 4 5 6 7 8 9
24 VCC 23 P15 22 P14 21 P13 20 P12 19 P11 18 P10 17 P9 16 P8 15 P7 14 P6 13 P5
P3 10 P4 11 GND 12
(Top view)
2
HD74HC674
Logic Diagram
IN PE CK P
P0
Q
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
VCC
P15 Mode CS CLK R/W SER/Q15
3
HD74HC674
DC Characteristics
Ta = 25°C Item Input voltage Symbol VIH Ta = –40 to +85°C Max — — — 0.5 1.35 1.8 — — — — — 0.1 0.1 0.1 0.33 0.33 ±1.0 40 ±5.0 A A A I OL = 6 mA I OL = 7.8 mA Vin ……
