SN54LS161A_TI 同步 4 位计数器

SN54LS161A的基本参数

制造厂商：TI
产品类别：逻辑和电压转换
技术类目：触发器、锁存器和寄存器 - 计数器
功能描述：同步 4 位计数器
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SN54LS161A的产品详情：

These synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting designs. The '160, '162, 'LS160A, 'LS162A, and 'S162 are decade counters and the '161, '163, 'LS161A, 'LS163A, and 'S163 are 4-bit binary counters. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enable inputs and internal gating. This mode of operation eliminates the output counting spikes that are normally associated with asynchronous (ripple clock) counters, however counting spikes may occur on the (RCO) ripple carry output. A buffered clock input triggers the four flip-flops on the rising 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 inputs. Low-to-high transitions at the load input of the '160 thru '163 should be avoided when the clock is low if the enable inputs are high at or before the transition. This restriction is not applicable to the 'LS160A thru 'LS163A or 'S162 or 'S163. The clear function for the '160, '161, 'LS160A, and '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 enable inputs. The clear function for the '162, '163, 'LS162A, 'LS163A, 'S162, and 'S163 is synchronous and a low level at the clear input 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 allows the count length to be modified easily as decoding the maximum count desired can be accomplished with one external NAND gate. The gate output is connected to the clear input to synchronously clear the counter to 0000 (LLLL). Low-to-high transitions at the clear input of the '162 and '163 should be avoided when the clock is low if the enable and load inputs are high at or before the transition.

The carry look-ahead circuitry provides for cascading counters 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-level output pulse with a duration approximately equal to the high-level portion of the Q_A output. This high-level overflow ripple carry pulse can be used to enable successive cascaded stages. High-to-low level transitions at the enable P or T inputs of the '160 thru '163 should occur only when the clock input is high. Transitions at the enable P or T inputs of the 'LS160A thru 'LS163A or 'S162 and 'S163 are allowed regardless of the level of the clock input.

'LS160A thru 'LS163A, 'S162 and 'S163 feature a fully independent clock circuit. Changes at 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, disabled, loading, or counting) will be dictated solely by the conditions meeting the stable setup and hold times.

SN54LS161A的优势和特性：

'160, '161, 'LS160A, 'LS161A … SYNCHRONOUS COUNTERS WITH DIRECT CLEAR '162, '163, 'LS162A, 'LS163A, 'S162, 'S163 … FULLY SYNCHRONOUS COUNTERS

Internal Look-Ahead for Fast Counting
Carry Output for n-Bit Cascading
Synchronous Counting
Synchronously Programmable
Load Control Line
Diode-Clamped Inputs

SN54LS161A的参数（英文）：

Function
Counter
Bits (#)
4
Technology Family
LS
Supply voltage (Min) (V)
4.5
Supply voltage (Max) (V)
5.5
Input type
Bipolar
Output type
Push-Pull
Features
High speed (tpd 10-50ns)

SN54LS161A具体的完整产品型号参数及价格（美元）：

SN54LS161A的完整型号有：76008012A、7600801EA、7600801FA、JM38510/31504B2A、JM38510/31504BEA、JM38510/31504BFA、M38510/31504B2A、M38510/31504BEA、M38510/31504BFA、SN54LS161AJ、SNJ54LS161AFK、SNJ54LS161AJ、SNJ54LS161AW，以下是这些产品的关键参数及官网采购报价：

76008012A，工作温度：-55 to 125，封装：LCCC (FK)-20，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网76008012A的批量USD价格：9.536（1000+）

7600801EA，工作温度：-55 to 125，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网7600801EA的批量USD价格：7.248（1000+）

7600801FA，工作温度：-55 to 125，封装：CFP (W)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网7600801FA的批量USD价格：7.461（1000+）

JM38510/31504B2A，工作温度：-55 to 125，封装：LCCC (FK)-20，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网JM38510/31504B2A的批量USD价格：10.077（1000+）

JM38510/31504BEA，工作温度：-55 to 125，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网JM38510/31504BEA的批量USD价格：7.248（1000+）

JM38510/31504BFA，工作温度：-55 to 125，封装：CFP (W)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网JM38510/31504BFA的批量USD价格：6.899（1000+）

M38510/31504B2A，工作温度：-55 to 125，封装：LCCC (FK)-20，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网M38510/31504B2A的批量USD价格：10.077（1000+）

M38510/31504BEA，工作温度：-55 to 125，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网M38510/31504BEA的批量USD价格：7.248（1000+）

M38510/31504BFA，工作温度：-55 to 125，封装：CFP (W)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网M38510/31504BFA的批量USD价格：6.899（1000+）

SN54LS161AJ，工作温度：-55 to 125，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网SN54LS161AJ的批量USD价格：7.11（1000+）

SNJ54LS161AFK，工作温度：-55 to 125，封装：LCCC (FK)-20，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网SNJ54LS161AFK的批量USD价格：9.536（1000+）

SNJ54LS161AJ，工作温度：-55 to 125，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网SNJ54LS161AJ的批量USD价格：7.248（1000+）

SNJ54LS161AW，工作温度：-55 to 125，封装：CFP (W)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网SNJ54LS161AW的批量USD价格：7.461（1000+）

SN54LS161A的评估套件：

SN54LS161A的电路图解：

SN54LS161A的评估套件：