參數(shù)資料
型號: 74HC193
廠商: NXP Semiconductors N.V.
元件分類: 通用總線功能
英文描述: Presettable synchronous 4-bit binary up/down counter
中文描述: 可預(yù)置同步4位二進制加/減計數(shù)器
文件頁數(shù): 2/13頁
文件大?。?/td> 95K
代理商: 74HC193
December 1990
2
Philips Semiconductors
Product specification
Presettable synchronous 4-bit binary
up/down counter
74HC/HCT193
FEATURES
Synchronous reversible 4-bit binary counting
Asynchronous parallel load
Asynchronous reset
Expandable without external logic
Output capability: standard
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT193 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT193 are 4-bit synchronous binary up/down
counters. Separate up/down clocks, CP
U
and
CP
D
respectively, simplify operation. The outputs change
state synchronously with the LOW-to-HIGH transition of
either clock input. If the CP
U
clock is pulsed while CP
D
is
held HIGH, the device will count up. If the CP
D
clock is
pulsed while CP
U
is held HIGH, the device will count down.
Only one clock input can be held HIGH at any time, or
erroneous operation will result. The device can be cleared
at any time by the asynchronous master reset input (MR);
it may also be loaded in parallel by activating the
asynchronous parallel load input (PL).
The “193” contains four master-slave JK flip-flops with the
necessary steering logic to provide the asynchronous
reset, load, and synchronous count up and count down
functions.
Each flip-flop contains JK feedback from slave to master,
such that a LOW-to-HIGH transition on the CP
D
input will
decrease the count by one, while a similar transition on the
CP
U
input will advance the count by one.
One clock should be held HIGH while counting with the
other, otherwise the circuit will either count by two’s or not
at all, depending on the state of the first flip-flop, which
cannot toggle as long as either clock input is LOW.
Applications requiring reversible operation must make the
reversing decision while the activating clock is HIGH to
avoid erroneous counts.
The terminal count up (TC
U
) and terminal count down
(TC
D
) outputs are normally HIGH. When the circuit has
reached the maximum count state of 15, the next
HIGH-to-LOW transition of CP
U
will cause TC
U
to go
LOW.
TC
U
will stay LOW until CP
U
goes HIGH again, duplicating
the count up clock.
Likewise, the TC
D
output will go LOW when the circuit is in
the zero state and the CP
D
goes LOW. The terminal count
outputs can be used as the clock input signals to the next
higher order circuit in a multistage counter, since they
duplicate the clock waveforms. Multistage counters will not
be fully synchronous, since there is a slight delay time
difference added for each stage that is added.
The counter may be preset by the asynchronous parallel
load capability of the circuit. Information present on the
parallel data inputs (D
0
to D
3
) is loaded into the counter
and appears on the outputs (Q
0
to Q
3
) regardless of the
conditions of the clock inputs when the parallel load
(PL) input is LOW. A HIGH level on the master reset (MR)
input will disable the parallel load gates, override both
clock inputs and set all outputs (Q
0
to Q
3
) LOW. If one of
the clock inputs is LOW during and after a reset or load
operation, the next LOW-to-HIGH transition of that clock
will be interpreted as a legitimate signal and will be
counted.
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參數(shù)描述
74HC193_13 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Presettable synchronous 4-bit binary up/down counter
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74HC193D,652 功能描述:計數(shù)器 IC 4BIT COUNTR U/D SYNC RoHS:否 制造商:NXP Semiconductors 計數(shù)器類型:Binary Counters 邏輯系列:74LV 位數(shù):10 計數(shù)法: 計數(shù)順序: 工作電源電壓:1 V to 5.5 V 工作溫度范圍:- 40 C to + 125 C 封裝 / 箱體:SOT-109 封裝:Reel
74HC193D,653 功能描述:計數(shù)器移位寄存器 4-BIT BINARY U/D COUNTER RoHS:否 制造商:Texas Instruments 計數(shù)器類型: 計數(shù)順序:Serial to Serial/Parallel 電路數(shù)量:1 封裝 / 箱體:SOIC-20 Wide 邏輯系列: 邏輯類型: 輸入線路數(shù)量:1 輸出類型:Open Drain 傳播延遲時間:650 ns 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝:Reel
74HC193DB 功能描述:計數(shù)器 IC 4BIT BIN UP/DN CNTER SYNCHRONOUS RoHS:否 制造商:NXP Semiconductors 計數(shù)器類型:Binary Counters 邏輯系列:74LV 位數(shù):10 計數(shù)法: 計數(shù)順序: 工作電源電壓:1 V to 5.5 V 工作溫度范圍:- 40 C to + 125 C 封裝 / 箱體:SOT-109 封裝:Reel