4位带2分频及5分频的二进制计数器
Dual 4−Stage Binary Ripple Counter with ÷2 and ÷5 Sections
High−Performance Silicon−Gate CMOS
The MC74HC390A is identical in pinout to the LS390. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs. This device consists of two independent 4−bit counters, each
composed of a divide−by−two and a divide−by−five section. The divide−by−two and divide−by−five counters have separate clock inputs, and can be cascaded to implement various combinations of ÷2 and/or ÷5 up to a ÷100 counter.
Features
•Output Drive Capability: 10 LSTTL Loads
•Outputs Directly Interface to CMOS, NMOS, and TTL
•Operating Voltage Range: 2.0 to 6.0 V
•Low Input Current: 1 A
•High Noise Immunity Characteristic of CMOS Devices
•In Compliance with the Requirements Defined by JEDEC Standard No 7A
•Chip Complexity: 244 FETs or 61 Equivalent Gates
•Pb−Free Packages are Available- .
