CD74HC193E.A中文资料德州仪器数据手册PDF规格书

特性 Features

• Synchronous Counting and Asynchronous

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• Two Outputs for N-Bit Cascading

• Look-Ahead Carry for High-Speed Counting

• Fanout (Over Temperature Range)

- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads

- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads

• Wide Operating Temperature Range . . . -55oC to 125oC

• Balanced Propagation Delay and Transition Times

• Significant Power Reduction Compared to LSTTL

Logic ICs

• HC Types

- 2V to 6V Operation

- High Noise Immunity: NIL = 30%, NIH = 30% of VCC

at VCC = 5V

• HCT Types

- 4.5V to 5.5V Operation

- Direct LSTTL Input Logic Compatibility,

VIL= 0.8V (Max), VIH = 2V (Min)

- CMOS Input Compatibility, Il ≤ 1μA at VOL, VOH

描述 Description

The ’HC192, ’HC193 and ’HCT193 are asynchronously

presettable BCD Decade and Binary Up/Down synchronous

counters, respectively.

Presetting the counter to the number on the preset data inputs

(P0-P3) is accomplished by a LOW asynchronous parallel

load input (PL). The counter is incremented on the low-to-high

transition of the Clock-Up input (and a high level on the Clock-

Down input) and decremented on the low to high transition of

the Clock-Down input (and a high level on the Clock-up input).

A high level on the MR input overrides any other input to clear

the counter to its zero state. The Terminal Count up (carry)

goes low half a clock period before the zero count is reached

and returns to a high level at the zero count. The Terminal

Count Down (borrow) in the count down mode likewise goes

low half a clock period before the maximum count (9 in the

192 and 15 in the 193) and returns to high at the maximum

count. Cascading is effected by connecting the carry and

borrow outputs of a less significant counter to the Clock-Up

and Clock-Down inputs, respectively, of the next most

significant counter.

If a decade counter is preset to an illegal state or assumes an

illegal state when power is applied, it will return to the normal

sequence in one count as shown in state diagram.