SN74LS93D - 4-Bit Binary Counter | Texas Instruments
料号： SN74LS93D ✓ 量产中SN74LS93D 概述
A binary counter is a sequential digital circuit that increments or decrements a binary state when an active clock transition occurs. The SN74LS93 belongs to the 74LS low-power Schottky TTL logic family, whose product hierarchy is 74LS counter → 4-bit binary counter → counter and divider logic → digital logic IC → semiconductor. Its four output bits allow a 16-state counting sequence, while independent gating provides useful divide-by-two and three-stage binary-counter arrangements described for the SN54/74LS90, SN54/74LS92 and SN54/74LS93 family.
The verified product information identifies the SN74LS93 as a 4-bit binary counter with a 14-pin SOIC package and negative-edge counting. One distributor result lists a maximum frequency of 42 MHz. The part is also described as supporting decade, divide-by-twelve and binary-counter functions, with gated sections that allow the designer to select the required counting arrangement. These characteristics make it suitable for legacy digital logic, frequency division, event counting and industrial control systems that retain 5 V TTL-compatible interfaces.
Ripple-counter architecture uses cascaded flip-flop stages, so each internal stage supplies clocking information to the following stage. This structure can introduce cumulative propagation delay between output transitions. Designers should therefore account for settling time when decoding several outputs together, particularly if the decoded value must remain glitch-free around a carry transition. The reset and control inputs should be driven with clean, stable logic to prevent unintended count initialization or count-enable behavior.
Typical uses include dividing a periodic signal, counting external events in legacy instrumentation, sequencing digital state machines and building compact binary accumulators. The counter is particularly relevant to brownfield industrial equipment, test fixtures and communication modules that use 74LS-family logic rather than modern programmable controllers. Because the verified material does not provide a detailed external clock or reset circuit, engineers should consult the manufacturer datasheet for exact truth-table and timing conditions before finalizing a board.
For a new design, keep clock and control traces short, provide a stable ground reference and decode outputs only after the expected propagation delay has elapsed. Avoid relying on decoded ripple outputs without considering transition hazards. Verify the actual device markings, supply requirements and absolute maximum ratings because only the counter width, package, edge sensitivity, temperature range and summarized functions were provided in the verified search data.
This page combines verified manufacturer and distributor information with practical selection guidance, a strict drop-in review, sourcing questions and design considerations for engineers maintaining TTL-based systems. It also clearly separates confirmed data from parameters that still require confirmation from the official SN74LS93 datasheet.
直接替换替代料： SN74LS93D ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
SN74LS93D 最大额定值与电气特性
| Counter Type | 4-bit binary counter |
| Number of Counting Elements | 1 element |
| Counter Width | 4 bit |
| Counting Direction | Up counter |
| Clock Edge | Negative edge |
| Architecture | 4-bit ripple counter |
| Maximum Frequency | 42 MHz |
| 封装 | 14-pin SOIC (D) |
| 引脚数 | 14 pin |
| 工作温度范围 | 0 °C to +70 °C |
| 安装类型 | Surface mount |
| Logic Family | 74LS |
| Internal Counter Elements | 4 master-slave flip-flops |
| Primary Counter Mode | Binary |
| Supported Count Functions | Decade, divide-by-twelve and binary counting |
SN74LS93D 14-pin soic (d) 引脚配置指南
SN74LS93D（14-pin soic (d) 封装）的引脚配置。 该数字 IC 包含 GPIO、通信接口（UART、SPI、I2C）和电源引脚。请参阅制造商数据手册以了解复用引脚功能和配置选项。对嵌入式系统设计和 PCB 布局至关重要。
暂无详细引脚数据： SN74LS93D.
请参阅 数据手册 以查看完整引脚配置。
典型应用
SN74LS93D 适用于 6 应用s: Legacy Frequency Divider, Industrial Event Counter, Digital State Sequencer, Test Fixture Timing Sequencer, Communications Bit-Rate Divider, Retrofit TTL Control Module.
Legacy Frequency Divider
The SN74LS93D is appropriate for legacy frequency-division circuits because it is identified as a 4-bit ripple counter with gated counting sections, negative-edge operation and a listed maximum frequency of 42 MHz. An incoming periodic signal can be routed through the applicable counting section to produce a lower-rate binary or divided clock. Because this is a ripple architecture, successive output bits can change at different times, so downstream logic should allow the full accumulated propagation delay before decoding a combined count. The verified 14-pin SOIC package also supports compact retrofit boards using 74LS TTL logic.
推荐
Industrial Event Counter
The SN74LS93D can count qualified digital events in legacy industrial control and instrumentation systems. Its confirmed 4-bit width provides 16 binary states, while the 42 MHz listed maximum frequency gives substantial timing margin for many industrial pulse rates. Input signals must first be conditioned so amplitude, rise time and pulse width satisfy the SN74LS93 requirements in the manufacturer datasheet. The 0 to 70 °C operating range suits ordinary indoor commercial equipment, although a mechanically noisy factory environment may also require filtering, shielding and an isolated input path.
推荐
Digital State Sequencer
The SN74LS93D fits a digital state sequencer when a design needs a compact binary count rather than a programmable state machine. The four counter outputs can represent the current count and can be decoded with external logic to generate repeatable control sequences. Negative-edge counting should be considered when clocking the next state, because simultaneous decoding around rollover can otherwise produce unintended intermediate states. The part's 14-pin SOIC footprint is particularly useful when maintaining older TTL boards whose logic levels and supply architecture are already established.
推荐
Test Fixture Timing Sequencer
The SN74LS93D is useful in legacy test fixtures that need deterministic step generation, repeat counts or pulse-rate division. A 42 MHz maximum-frequency listing supports common low-to-moderate-speed fixture signals, and the 4-bit output provides enough states for short test sequences without requiring a large programmable counter. Engineers should add timing margins for external decoding gates and probe loading, particularly at the output transitions that occur during ripple carry. The SOIC package is also convenient for repair boards and compact adapter fixtures.
推荐
Communications Bit-Rate Divider
The SN74LS93D can support a legacy communications design that divides a periodic clock before a decoder or protocol controller consumes it. Its confirmed 4-bit counter structure and gated sections permit several division arrangements, while the 14-pin SOIC package makes it practical for retrofitting established interface boards. The design must ensure that the divided clock meets the receiving logic's minimum period and jitter limits. External synchronization is particularly important when a divided signal crosses between unrelated clock domains or when ripple transitions could appear as narrow intermediate pulses.
推荐
Retrofit TTL Control Module
The SN74LS93D is a practical choice for retrofit modules that must retain 74LS-family behavior, supply rails and connector conventions. Its 14-pin SOIC (D) package supports conventional surface-mount assembly, while the 0 to 70 °C range targets commercial indoor equipment. Retrofitting is more reliable than replacing the logic family with mixed-voltage modern ICs because input thresholds, fan-out and timing behavior remain important system assumptions. Before substitution, verify every connected net against the manufacturer pinout and check whether the replacement remains available in the required package and temperature grade.
推荐
推荐产品汇总
工程参考数据： SN74LS93D ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | SN74LS93D |
|---|---|---|
| Brand | Texas Instruments | onsemi |
| Package | 14-pin SOIC (D) | 14-pin SOIC (D) |
| Counter Type | 4-bit binary counter | 4-bit binary counter |
| Number of Counting Elements | 1 element | 1 element |
| Counting Direction | Up counter | Up counter |
| Clock Edge | Negative edge | Negative edge |
| Architecture | 4-bit ripple counter | 4-bit ripple counter |
关键差异点
- Directly identified as a negative-edge 4-bit binary counter （对比 SN74LS293D)
- Exact 14-pin SOIC orderable configuration （对比 SN74LS93D from onsemi)
- Verified high-speed ripple-counter architecture （对比 Generic 4-bit binary counter)
设计说明
Treat all four counter outputs as ripple-stage signals rather than as outputs that change simultaneously. During rollover, adjacent bits can transition at different times and briefly represent an intermediate count. If the outputs are decoded, include the worst-case cumulative propagation delay in the design and use a registered strobe or synchronized decode stage. The verified material does not provide individual propagation-delay values, so these limits must be obtained from the manufacturer timing table before release.
Place the SN74LS93D close to the clock and logic circuitry that drives its count-enable, clear and output-decoding paths. Keep the 14-pin SOIC ground connection and supply-return path compact, and route the clock away from noisy analog or switching-node traces. Although the verified data does not specify a dedicated exposed pad, the SOIC device still needs a continuous ground-plane reference beneath the package and short supply bypass connections close to the device.
Do not assume that any 4-bit counter is a drop-in replacement. The verified comparison search names SN74LS293D, but it does not prove pin compatibility, and its reset or control interface may differ from SN74LS93D. Likewise, SN74LS93DR is a suffix variation of the same Texas Instruments device rather than a distinct engineering alternative. Verify the original schematic, manufacturer pin drawing, truth table, clock-edge convention, clear polarity and propagation timing before approving any substitute.
合规信息
The verified search results identify the device and package but do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free or conflict-minerals declarations. Compliance and qualification must be confirmed from the manufacturer product page or current declarations.
