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参数资料
| 型号： | SN74LS161AD |
| 厂商： | MOTOROLA INC |
| 元件分类： | 计数器 |
| 英文描述： | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP BINARY COUNTER, PDSO16 |
| 封装： | SOIC-16 |
| 文件页数： | 2/6页 |
| 文件大小： | 79K |
| 代理商： | SN74LS161AD |
*For the LS162A and
*LS163A only.
H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
5-2
FAST AND LS TTL DATA
SN54/74LS160A
SN54/74LS161A
SN54/74LS162A
SN54/74LS163A
STATE DIAGRAM
LS160A
LS162A
LS161A
LS163A
0123
4
5
6
7
8
9
10
11
12
13
14
15
01
23
4
5
6
7
8
9
10
11
12
13
14
15
NOTE:
The LS160A and LS162A can be preset to any state,
but will not count beyond 9. If preset to state 10, 11,
12, 13, 14, or 15, it will return to its normal sequence
within two clock pulses.
LOGIC EQUATIONS
Count Enable = CEP
CET PE
TC for LS160A & LS162A = CET
Q0 Q1 Q2 Q3
TC for LS161A & LS163A = CET
Q0 Q1 Q2 Q3
Preset = PE
CP + (rising clock edge)
Reset = MR (LS160A & LS161A)
Reset = SR
CP + (rising clock edge)
Reset = (LS162A & LS163A)
FUNCTIONAL DESCRIPTION
The LS160A / 161A / 162A / 163A are 4-bit synchronous
counters with a synchronous Parallel Enable (Load) feature.
The counters consist of four edge-triggered D flip-flops with
the appropriate data routing networks feeding the D inputs. All
changes of the Q outputs (except due to the asynchronous
Master Reset in the LS160A and LS161A) occur as a result of,
and synchronous with, the LOW to HIGH transition of the
Clock input (CP). As long as the set-up time requirements are
met, there are no special timing or activity constraints on any
of the mode control or data inputs.
Three control inputs — Parallel Enable (PE), Count Enable
Parallel (CEP) and Count Enable Trickle (CET) — select the
mode of operation as shown in the tables below. The Count
Mode is enabled when the CEP, CET, and PE inputs are HIGH.
When the PE is LOW, the counters will synchronously load the
data from the parallel inputs into the flip-flops on the LOW to
HIGH transition of the clock. Either the CEP or CET can be
used to inhibit the count sequence. With the PE held HIGH, a
LOW on either the CEP or CET inputs at least one set-up time
prior to the LOW to HIGH clock transition will cause the
existing output states to be retained. The AND feature of the
two Count Enable inputs (CET
CEP) allows synchronous
cascading without external gating and without delay accu-
mulation over any practical number of bits or digits.
The Terminal Count (TC) output is HIGH when the Count
Enable Trickle (CET) input is HIGH while the counter is in its
maximum count state (HLLH for the BCD counters, HHHH for
the Binary counters). Note that TC is fully decoded and will,
therefore, be HIGH only for one count state.
The LS160A and LS162A count modulo 10 following a
binary coded decimal (BCD) sequence. They generate a TC
output when the CET input is HIGH while the counter is in state
9 (HLLH). From this state they increment to state 0 (LLLL). If
loaded with a code in excess of 9 they return to their legitimate
sequence within two counts, as explained in the state
diagram. States 10 through 15 do
not generate a TC output.
The LS161A and LS163A count modulo 16 following a
binary sequence. They generate a TC when the CET input is
HIGH while the counter is in state 15 (HHHH). From this state
they increment to state 0 (LLLL).
The Master Reset (MR) of the LS160A and LS161A is
asynchronous. When the MR is LOW, it overrides all other
input conditions and sets the outputs LOW. The MR pin should
never be left open. If not used, the MR pin should be tied
through a resistor to VCC, or to a gate output which is
permanently set to a HIGH logic level.
The active LOW Synchronous Reset (SR) input of the
LS162A and LS163A acts as an edge-triggered control input,
overriding CET, CEP and PE, and resetting the four counter
flip-flops on the LOW to HIGH transition of the clock. This
simplifies the design from race-free logic controlled reset
circuits, e.g., to reset the counter synchronously after
reaching a predetermined value.
MODE SELECT TABLE
*SR
PE
CET
CEP
Action on the Rising Clock Edge (
)
L
X
RESET (Clear)
H
L
X
LOAD (Pn → Qn)
H
COUNT (Increment)
H
L
X
NO CHANGE (Hold)
H
X
L
NO CHANGE (Hold)
相关PDF资料 |
PDF描述 |
|---|---|
| SN74LS162AD | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP DECADE COUNTER, PDSO16 |
| SN74LS161ANS | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP BINARY COUNTER, PDIP16 |
| SN74LS160AJS | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP DECADE COUNTER, CDIP16 |
| SN74LS162ANS | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP DECADE COUNTER, PDIP16 |
| SN74LS163AM | LS SERIES, SYN POSITIVE EDGE TRIGGERED 4-BIT UP BINARY COUNTER, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SN74LS161ADE4 | 功能描述:计数器 IC 4-Bit Synchronous Binary Counters 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 |
| SN74LS161ADG4 | 功能描述:计数器 IC Sync 4B Binary Counters 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 |
| SN74LS161ADR | 功能描述:计数器 IC 4-Bit Synchronous Binary Counters 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 |
| SN74LS161ADR2 | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| SN74LS161ADRE4 | 功能描述:计数器 IC 4-Bit Synchronous Binary Counters 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 |
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