HD74HC590 Datasheet, PDF (1/11 Pages) Hitachi Semiconductor – 8-bit Binary Counter/Register (with 3-state outputs)

HD74HC590
8-bit Binary Counter/Register (with 3-state outputs)
Description
This device each contains an 8-bit binary counter that feeds an 8-bit storage register. The storage register
has parallel outputs. Separate clocks are provided for both the binary counter and storage register. The
binary counter features a direct clear input CCLR and a count enable input CCKEN. For cascading a ripple
carry output RCO is provided. Expansion is easily accomplished by tying RCO of the first stage to CCKEN
of the second stage, etc.
Both the counter and register clocks are positive-edge triggered. If the user wishes to connect both clocks
together, the counter state will always be one count ahead of the register, Internal circuitry prevents
clocking from the clock enable.
Features
• High Speed Operation: t_pd (RCK to Q) = 18.5 ns typ (C_L = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads
• Wide Operating Voltage: V_CC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I_CC (static) = 4 µA max (Ta = 25°C)