LM393ST - Dual Open-Collector Comparator | STMicroelectronics
MPN： LM393ST ✓ 啟用中LM393ST 概覽
A voltage comparator is an analog integrated circuit that compares two input voltages and changes its output state when the non-inverting input exceeds the inverting input, or vice versa. Within the broader semiconductor hierarchy, a comparator belongs to the amplifier and signal-conditioning IC family, where it supports threshold detection, decision-making, and feedback control. Unlike a general-purpose operational amplifier, the LM393ST uses open-collector outputs designed for wired logic, pull-up arrangements, and low-voltage system interfacing.
Each LM393ST channel includes an open-collector output capable of sinking current while remaining in a high-impedance state when inactive. External pull-up resistors establish the high output level, allowing the device to interface with a selected supply voltage and potentially support open-collector bus arrangements. The dual-channel configuration provides two independent comparators in one package, reducing board area when a design requires more than one threshold decision.
The LM393 family is specified for operation from 2 V to 36 V on a single supply, while the STMicroelectronics listing describes rail-to-rail input behavior. This wide supply range accommodates low-voltage control systems as well as industrial environments operating from higher rails. The open-collector outputs and broad input capability make the device useful for monitoring supply rails, detecting sensor crossings, implementing window functions with additional circuitry, and building basic automation-control decisions.
Because the outputs are open collector, every board-level implementation must include suitable pull-up components unless the outputs are connected to another compatible open-collector load. The pull-up voltage should remain within the electrical limits of the connected logic, while the pull-up resistance must balance rise time, power consumption, and output-current capability. Short traces and a common ground reference help prevent comparison errors when sensing small voltage differences.
Use the LM393ST when two independent, general-purpose comparisons are needed in an 8-pin MiniSO design and open-collector interfacing is desirable. Review the manufacturer pin description and electrical limits before final PCB routing, particularly input common-mode range, output sink current, supply sequencing, and exposed thermal behavior.
直接替換替代品，適用於 LM393ST — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
LM393ST 最大額定值與電氣特性
| Comparator Type | Dual general-purpose voltage comparator |
| Number of Channels | 2 channels |
| 輸出類型 | Open-collector |
| Input Common-Mode Capability | Rail-to-rail |
| Single-Supply Operating Voltage | 2 V to 36 V |
| Maximum Supply Voltage | 36 V |
| 封裝 | 8-MiniSO |
| 腳位數 | 8 pins |
| 安裝類型 | Surface mount |
| Automotive Qualification | Not applicable |
| RoHS 狀態 | ROHS3 compliant |
LM393ST 8-miniso 腳位配置指南
LM393ST（8-miniso 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： LM393ST.
請參閱 資料表 以查看完整腳位配置。
典型應用
LM393ST 適用於 6 應用s: Industrial Sensor Threshold Detection, Power-Supply Overvoltage Detection, Motor and Actuator Control, Battery Threshold Protection, Automated Equipment Logic, Communications and Network Equipment.
Industrial Sensor Threshold Detection
The LM393ST suits industrial sensor interfaces that require two independent threshold decisions within a compact 8-MiniSO footprint. Each channel can compare a conditioned sensor voltage with a reference, while the open-collector output provides a pulled-down fault event or pulled-high ready state through an external resistor. The 2 V to 36 V single-supply range supports both compact control electronics and higher industrial rails. Design protection around exposed sensor wiring, validate the selected temperature grade, and choose pull-up values that satisfy the required logic rise time without excessive continuous power.
推薦
Power-Supply Overvoltage Detection
The LM393ST can monitor a divided power rail against a reference and provide an open-collector fault indication when the monitored voltage crosses a defined limit. Its 2 V to 36 V operating range is useful across multiple supply architectures, and rail-to-rail input behavior supports direct sensing near the supply rails when the input limits permit. A fault signal can drive a system shutdown or status latch through a pull-up resistor. Resistor tolerance, input bias effects, and propagation delay determine threshold accuracy, so include those effects in the safety-margin calculation.
推薦
Motor and Actuator Control
The two channels in the LM393ST can support independent limit decisions in motor, valve, or actuator-control circuits. One channel may monitor a command or feedback signal while the other evaluates a position, speed, or travel limit, producing open-collector events for a controller or driver stage. The 8-MiniSO package keeps the sensing section compact, while the wide single-supply range accommodates industrial control systems. Relay, motor, and actuator transients require external protection because the comparator is intended for signal conditioning and logic-level decisions, not direct high-energy load driving.
推薦
Battery Threshold Protection
The LM393ST is applicable to battery systems that need early warning when a cell or rail approaches a defined limit. Its family operates from 2 V on a single supply, and the two channels can monitor charge and discharge thresholds without requiring two packages. Open-collector outputs allow pull-ups to the logic rail used by the battery controller. Divider resistance should balance battery drain against input bias error, while the selected resistor and source qualification should be checked for temperature and leakage effects. Accurate protection requires checking the actual cell range against the comparator's input and supply limits.
推薦
Automated Equipment Logic
The LM393ST can implement discrete limit checks and interlock decisions in automated equipment where two comparator functions are needed close to a connector or control board. Each open-collector output can participate in a wired logic condition, allowing a single fault line to represent several limit states. The dual-channel 8-MiniSO arrangement reduces board area, while the 2 V to 36 V supply range provides design flexibility. For reliable operation, keep sensing traces short, maintain a low-impedance common ground, add filtering for noisy analog inputs, and verify the exact component's absolute maximum ratings against the machine's electrical environment.
推薦
Communications and Network Equipment
The LM393ST can provide receive-line threshold checks, supply-window detection, or fault qualification in communications equipment. Its two open-collector channels can monitor separate signal or rail conditions, and external pull-ups permit connection to the equipment's internal logic supply. The broad 2 V to 36 V range accommodates cards operating from low-voltage rails through higher industrial supplies. High-speed communications decisions may require a lower-delay comparator, so compare propagation delay before using this general-purpose device for timing-critical line coding. Add filtering and protection at externally accessible connectors.
推薦
推薦產品摘要
工程參考資料，適用於 LM393ST — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LM393ST |
|---|---|---|
| Package | 8-MiniSO | 8-MiniSO |
| Brand | STMicroelectronics | ROHM Semiconductor |
| Comparator Configuration | Dual general-purpose comparator | Dual general-purpose comparator |
| Output Type | Open-collector | Open-collector |
| Input Common-Mode Capability | Rail-to-rail | Rail-to-rail |
| Number of Channels | 2 channels | 2 channels |
| Mounting Type | Surface mount | Surface mount |
主要差異化特點
- Matched package and comparator configuration (對比LM393ST from ROHM Semiconductor)
- Broad single-supply operating range (對比LM393LV from Texas Instruments)
- Two independent general-purpose channels (對比Single-channel comparator alternatives)
設計說明
Place the LM393ST close to the signals being compared and provide a low-impedance ground return to minimize differential pickup and ground bounce. Keep the pull-up resistor near the corresponding output so the open-collector node has a short route to its receiver. When either input is connected through long wiring, add series resistance and input filtering at the connector rather than relying on the comparator alone to reject industrial noise.
The open-collector output does not require a dedicated high-voltage output driver, but every output node still needs a pull-up resistor. Choose the resistor to satisfy the receiver's rise-time requirement while keeping continuous dissipation within the resistor's rating. If the pull-up rail differs from the comparator supply, confirm that the resulting output-node voltage remains within the LM393ST's permitted limits.
Do not treat the open-collector output as a push-pull logic output. Without a pull-up, the output remains high-impedance after the sink transistor turns off, which can produce undefined voltage transitions in downstream logic. Also verify the manufacturer's pin map because the LM393ST ordering code is used by multiple manufacturers. Confirm input polarity, output assignments, supply pins, and grounding before fabricating the PCB.
A comparator output transitions when the differential input passes through its offset region, so slow or noisy input crossings can cause repeated output toggling. Keep the input network low impedance and use hysteresis through positive feedback when the application must avoid chatter. Select the hysteresis amplitude with enough margin to exceed input offset and noise while remaining inside the usable common-mode range.
合規資訊
The component catalog identifies the device as ROHS3 compliant. REACH and moisture-sensitivity details are not stated in the catalog excerpts, and no automotive qualification is identified.
