参数资料
型号: DM74LS163A
厂商: National Semiconductor Corporation
元件分类: 计数器
英文描述: Synchronous 4-Bit Binary Counters(同步4位二进制计数器)
中文描述: 同步4位二进制计数器(同步4位二进制计数器)
文件页数: 1/12页
文件大小: 210K
代理商: DM74LS163A
TLF6397
54LS161ADM54LS161ADM74LS161A
54LS163ADM54LS163ADM74LS163A
Synchronous
4-Bit
Binary
Counters
May 1992
54LS161ADM54LS161ADM74LS161A
54LS163ADM54LS163ADM74LS163A
Synchronous 4-Bit Binary Counters
General Description
These synchronous presettable counters feature an inter-
nal carry look-ahead for application in high-speed counting
designs The LS161A and LS163A are 4-bit binary counters
The carry output is decoded by means of a NOR gate thus
preventing spikes during the normal counting mode of oper-
ation Synchronous operation is provided by having all flip-
flops clocked simultaneously so that the outputs change co-
incident with each other when so instructed by the count-
enable inputs and internal gating This mode of operation
eliminates the output counting spikes which are normally
associated with asynchronous (ripple clock) counters A
buffered clock input triggers the four flip-flops on the rising
(positive-going) edge of the clock input waveform
These counters are fully programmable that is the outputs
may be preset to either level As presetting is synchronous
setting up a low level at the load input disables the counter
and causes the outputs to agree with the setup data after
the next clock pulse regardless of the levels of the enable
input The clear function for the LS161A is asynchronous
and a low level at the clear input sets all four of the flip-flop
outputs low regardless of the levels of clock load or en-
able inputs The clear function for the LS163A is synchro-
nous and a low level at the clear inputs sets all four of the
flip-flop outputs low after the next clock pulse regardless of
the levels of the enable inputs This synchronous clear al-
lows the count length to be modified easily as decoding the
maximum count desired can be accomplished with one ex-
ternal NAND gate The gate output is connected to the clear
input to synchronously clear the counter to all low outputs
The carry look-ahead circuitry provides for cascading coun-
ters for n-bit synchronous applications without additional
gating Instrumental in accomplishing this function are two
count-enable inputs and a ripple carry output
Both count-enable inputs (P and T) must be high to count
and input T is fed forward to enable the ripple carry output
The ripple carry output thus enabled will produce a high-lev-
el output pulse with a duration approximately equal to the
high-level portion of the QA output This high-level overflow
ripple carry pulse can be used to enable successive cascad-
ed stages High-to-low level transitions at the enable P or T
inputs may occur regardless of the logic level of the clock
These counters feature a fully independent clock circuit
Changes made to control inputs (enable P or T or load) that
will modify the operating mode have no effect until clocking
occurs The function of the counter (whether enabled dis-
abled loading or counting) will be dictated solely by the
conditions meeting the stable set-up and hold times
Features
Y
Synchronously programmable
Y
Internal look-ahead for fast counting
Y
Carry output for n-bit cascading
Y
Synchronous counting
Y
Load control line
Y
Diode-clamped inputs
Y
Typical propagation time clock to Q output 14 ns
Y
Typical clock frequency 32 MHz
Y
Typical power dissipation 93 mW
Y
Alternate
MilitaryAerospace
device
(54LS161
54LS163) is available Contact a National Semiconduc-
tor Sales OfficeDistributor for specificaitons
Connection Diagram
Dual-In-Line Package
TLF6397 – 1
Order Numbers 54LS161ADMQB 54LS161AFMQB
54LS161ALMQB 54LS163ADMQB 54LS163AFMQB
54LS163ALMQB DM54LS161AJ DM54LS161AW
DM54LS163AJ DM54LS163AW DM74LS161AM
DM74LS161AN DM74LS163AM or DM74LS163AN
See NS Package Number E20A J16A
M16A N16E or W16A
C1995 National Semiconductor Corporation
RRD-B30M105Printed in U S A
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相关代理商/技术参数
参数描述
DM74LS163AM 功能描述:计数器 IC Syn 4-Bit Binary Ctr RoHS:否 制造商:NXP Semiconductors 计数器类型:Binary Counters 逻辑系列:74LV 位数:10 计数法: 计数顺序: 工作电源电压:1 V to 5.5 V 工作温度范围:- 40 C to + 125 C 封装 / 箱体:SOT-109 封装:Reel
DM74LS163AMX 功能描述:计数器 IC Syn 4-Bit Binary Ctr RoHS:否 制造商:NXP Semiconductors 计数器类型:Binary Counters 逻辑系列:74LV 位数:10 计数法: 计数顺序: 工作电源电压:1 V to 5.5 V 工作温度范围:- 40 C to + 125 C 封装 / 箱体:SOT-109 封装:Reel
DM74LS163AN 功能描述:计数器 IC Syn 4-Bit Binary Ctr RoHS:否 制造商:NXP Semiconductors 计数器类型:Binary Counters 逻辑系列:74LV 位数:10 计数法: 计数顺序: 工作电源电压:1 V to 5.5 V 工作温度范围:- 40 C to + 125 C 封装 / 箱体:SOT-109 封装:Reel
DM74LS163AN/A+ 制造商:Texas Instruments 功能描述:
DM74LS164 WAF 制造商:Fairchild Semiconductor Corporation 功能描述: