器件名称:
74HC91
功能描述:
8-bit Shift Register
文件大小:
49.79KB 共9页
简 介:
HD74HC91 8-bit Shift Register Description This serial-in, serial-out, 8-bit shift register is composed of eight R-S master-slave flip-flops, input gating, and a clock drive. Single-rail data and input control are gated through inputs A and B and an internal inverter to form the complementary inputs to the first bit of the shift register. Drive for the internal common clock line is provided by an inverting clock driver. This clock pulse inverter/driver causes these circuits to shift information one bit on the positive edge of an input clock pulse. Features High Speed Operation: tpd (Data Word Input to Output) = 21 ns typ (CL = 50 pF) High Output Current: Fanout of 10 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 tn A H L X X : tn : t n + 8: B H X L Irrelevant Reference bit time, clock low Bit time after 8 low-to-high clock transitions Outputs tn + 8 QH H L L QH L H H HD74HC91 Pin Arrangement NC NC NC NC Vcc NC NC 1 2 3 4 5 6 7 (Top View) CK QH QH A B 14 13 12 11 10 9 8 QH QH A Inputs B GND Clock NC 2 HD74HC91 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 A A I OL = 4 mA I OL = 5.2 mA Vin = VCC or GND Vin = VCC or GND, Iout = 0 A V I OH = –4 mA I OH = –5.2 mA Vin = VIH or VIL I OL = 20 A V Vin = VIH or VIL I OH = –20 A V Unit V Test Conditions VCC (V)……
