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DM74LS469N

更新时间： 2024-02-16 16:34:12

品牌	Logo	应用领域
美国国家半导体 - NSC		计数器
页数	文件大小	规格书
4页	125K
描述
DM54LS469/DM74LS469 8-Bit Up/Down Counter

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数据手册

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DM74LS469N 数据手册

July 1989

DM54LS469/DM74LS469 8-Bit Up/Down Counter

General Description

The ‘LS469 is an 8-bit synchronous up/down counter with

parallel load and hold capability. Three function-select in-

puts (LD, UD, CBI) provide one of four operations which

occur synchronously on the rising edge of the clock (CK).

The output register (Q –Q ) is enabled when OE is LOW,

7 0

and disabled (HI-Z) when OE is HIGH. The output drivers

will sink the 24 mA required for many bus-interface stan-

dards. Two or more ‘LS469 octal up/down counters may be

cascaded to provide larger counters.

The LOAD operation loads the inputs (D –D ) into the out-

put register (Q –Q ). The HOLD operation holds the previ-

Features/Benefits

ous value regardless of clock transitions. The INCREMENT

operation adds one to the output register when the carry-in

8-bit up/down counter for microprogram-counter, DMA

controller and general-purpose counting applications

input is TRUE (CBI LOW), otherwise the operation is a

HOLD. The carry-out (CBO) is TRUE (CBO LOW) when

8 bits matches byte boundaries

the output register (Q –Q ) is all HIGHs, otherwise FALSE

Bus-structured pinout

(CBO HIGH). The DECREMENT operation subtracts one

from the output register when the borrow-in input is TRUE

24-pin SKINNYDIP saves space

TRI-STATE outputs drive bus lines

Low current PNP inputs reduce loading

(CBI LOW), otherwise the operation is a HOLD. The bor-

row-out (CBO) is TRUE (CBO LOW) when the output reg-

Expandable in 8-bit increments

ister (Q –Q ) is all LOWs, otherwise FALSE (CBO HIGH).

Connection Diagram

Standard Test Load

Top View

TL/L/8333–3

TL/L/8333–1

Order Number DM54LS469J,

DM74LS469J or DM74LS469N

See NS Package Number J24F or N24C

Function Table

OE CK LD UD CBI D7–D0 Q7–Q0

Operation

HI-Z

LOAD

HOLD

Q plus 1 INCREMENT

HOLD

Q minus 1 DECREMENT

TRI-STATEÉ is a registered trademark of National Semiconductor Corp.

1995 National Semiconductor Corporation

TL/L/8333

RRD-B30M115/Printed in U. S. A.

12 3 4

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与DM74LS469N相关器件

型号	品牌	获取价格	描述	数据表
DM74LS469N/A+	ETC	获取价格	Synchronous Up/Down Counter
DM74LS469N/B+	ETC	获取价格	Synchronous Up/Down Counter
DM74LS47	FAIRCHILD	获取价格	BCD to 7-Segment Decoder/Driver with Open-Collector Outputs
DM74LS47	NSC	获取价格	BCD TO 7-SEGMENT DECODER/DRIVER
DM74LS47_07	FAIRCHILD	获取价格	BCD to 7-Segment Decoder/Driver with Open-Collector Outputs
DM74LS471J	NSC	获取价格	(256 X 8) 2048-BIT TTL PROM
DM74LS471J/A+	ETC	获取价格	x8 PROM
DM74LS471J/B+	ETC	获取价格	x8 PROM
DM74LS471N	NSC	获取价格	(256 X 8) 2048-BIT TTL PROM
DM74LS471N/A+	ETC	获取价格	x8 PROM