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参数资料
| 型号： | 74ALS161BDB |
| 厂商： | NXP SEMICONDUCTORS |
| 元件分类： | 通用总线功能 |
| 英文描述： | 4-bit binary counter |
| 中文描述： | ALS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP BINARY COUNTER, PDSO16 |
| 封装： | PLASTIC, SOT-338-1, SSOP2-16 |
| 文件页数： | 2/14页 |
| 文件大小： | 168K |
| 代理商： | 74ALS161BDB |
Philips Semiconductors
Product specification
74ALS161B/74ALS163B
4-bit binary counter
74ALS161B
74ALS163B
4-bit binary counter, asynchronous reset
4-bit binary counter, synchronous reset
2
1991 Feb 08
853–1350 01670
FEATURES
Synchronous counting and loading
Two count enable inputs for n-bit cascading
Positive edge-triggered clock
Asynchronous reset (74ALS161B)
Synchronous reset (74ALS163B)
High speed synchronous expansion
Typical count rate of 140MHz
TYPE
TYPICAL f
MAX
TYPICAL
SUPPLY CURRENT
(TOTAL)
74ALS161B
140MHz
10mA
74ALS163B
140MHz
10mA
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
V
CC
= 5V
±
10%,
T
amb
= 0
°
C to +70
°
C
DRAWING
NUMBER
16-pin plastic DIP
74ALS161BN, 74ALS163BN
SOT38-4
16-pin plastic SO
74ALS161BD, 74ALS163BD
SOT109-1
16-pin plastic SSOP
Type II
74ALS161BDB,
74ALS163BDB
SOT338-1
DESCRIPTION
Synchronous presettable 4-bit binary counters (74ALS161B,
74ALS163B) feature an internal carry look-ahead and can be used
for high speed counting. Synchronous operation is provided by
having all flip-flops clocked simultaneously on the positive-going
edge of the clock. The clock input is buffered.
The outputs of the counters may be preset to High or Low level. A
Low level at the parallel enable (PE) input disables the counting
action and causes the data at the D0 – D3 inputs to be loaded into
the counter on the positive-going edge of the clock (provided that
the setup and hold requirements for PE are met). Preset takes place
regardless of the levels at count enable (CEP, CET) inputs.
A Low level at the master reset (MR) input sets all the four outputs
of the flip-flops (Q0 – Q3) in 74ALS161B to Low levels, regardless of
the levels at CP, PE, CET and CEP inputs (thus providing an
asynchronous clear function).
For the 74ALS163B the clear function is synchronous. A Low level
at the synchronous reset (SR) input sets all four outputs of the
flip-flops (Q0 – Q3) to Low levels after the next positive-going
transition on the clock (CP) input ( provided that the setup and hold
time requirements for SR are met). This action occurs regardless of
the levels at CP, PE, CET and CEP inputs. The synchronous reset
feature enables the designer to modify the maximum count with only
one external NAND gate (see Figure 1).
The carry look-ahead simplifies serial cascading of the counters.
Both count enable (CEP and CET) inputs must be High to count.
The CET input is fed forward to enable the TC output. The TC
output thus enabled will produce a High output pulse of a duration
approximately equal to the High level output of Q0. This pulse can
be used to enable the next cascaded stage (see Figure 2).
The TC output is subjected to decoding spikes due to internal race
conditions, Therefore, it is not recommended for use as clock or
asynchronous reset for flip-flops, registers, or counters.
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
74ALS (U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
D0 – D3
Data inputs
1.0/1.0
20
μ
A/0.1mA
20
μ
A/0.1mA
20
μ
A/0.1mA
20
μ
A/0.1mA
20
μ
A/0.1mA
20
μ
A/0.1mA
20
μ
A/0.1mA
CEP
Count enable parallel input (active-Low)
1.0/1.0
CET
Count enable trickle input (active-Low)
1.0/1.0
CP
Clock input (active rising edge)
1.0/1.0
PE
Parallel enable input (active-Low)
1.0/1.0
MR
Asynchronous master reset input (active-Low) for 74ALS161B
1.0/1.0
SR
Asynchronous reset input (active-Low) for 74ALS163B
1.0/1.0
Q0 – Q3
Flip-flop outputs
20/80
0.4mA/8mA
TC
Terminal count output (active-Low)
One (1.0) ALS unit load is defined as: 20
μ
A in the High state and 0.1mA in the Low state.
20/80
0.4mA/8mA
NOTE:
相关PDF资料 |
PDF描述 |
|---|---|
| 74ALS164 | 8-bit serial-in parallel-out shift register |
| 74ALS164D | 8-bit serial-in parallel-out shift register |
| 74ALS164N | 8-bit serial-in parallel-out shift register |
| 74ALS174 | Hex D flip-flop |
| 74ALS174D | Hex D flip-flop |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 74ALS161BN | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:4-bit binary counter |
| 74ALS163B | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:4-bit binary counter |
| 74ALS163BD | 制造商:NXP Semiconductors 功能描述:Counter, Up, 4 Bit Binary, 16 Pin, Plastic, SOP |
| 74ALS163BDB | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:4-bit binary counter |
| 74ALS163BN | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:4-bit binary counter |
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