LM293AD - Dual Differential Comparator, 2-36V | Texas Instruments
MPN: LM293AD ✓ نشطLM293AD نظرة عامة
A differential comparator is an integrated circuit that compares two input voltages and changes its output state according to their relationship. Its two channels can monitor thresholds, detect crossings, implement window functions, or generate control signals. The LM293 belongs to the comparator hierarchy within analog interface ICs, where it bridges analog sensing and digital control logic.
The LM293AD operates from 2 V to 36 V and provides a response time of approximately 300 ns. Its common-mode input range includes ground, and its differential input range can equal the maximum-rated supply voltage of ±38 V according to the manufacturer product information. Open-collector outputs support wired logic, pull-up arrangements, level translation, and compatibility with TTL, MOS, and CMOS systems.
Each comparator section compares an inverting input with a non-inverting input. When the non-inverting input is higher, the corresponding open-collector output transistor turns off; when the inverting input is higher, the output transistor turns on. An external pull-up resistor is required for conventional open-collector operation. The two channels share the supply pins but retain separate input and output pins.
Typical uses include industrial sensor interfaces, battery monitoring, power-supply fault detection, overvoltage protection, relay or LED indication, and control systems that compare an analog voltage against a reference. The wide operating supply range is useful when the comparator must tolerate industrial transients while operating from a higher-voltage rail.
Designers should verify input and output absolute maximum ratings, provide adequate pull-up resistors, maintain a valid common-mode range, and account for output-current limits when several wired-open-collector outputs share a bus. Because the outputs can sink current but cannot source it independently, external pull-ups determine the high logic voltage and rise-time behavior.
This product page combines manufacturer specifications, verified distributor listings, same-package replacement guidance, and practical comparator-design notes. It helps engineers evaluate the LM293AD for industrial threshold detection, protection, monitoring, and open-collector interface designs without confusing it with open-drain parts that use different output structures.
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الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع LM293AD (نفس عامل الشكل والبصمة) — يختلف في Output Type.
LM293ADR
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM293ADRE4
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM393AD
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LM2903AD
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM293AD
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LM293AD الحدود القصوى والخصائص الكهربائية
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Supply Voltage Range | 2 V to 36 V |
| Differential Input Voltage Range | -38 V to +38 V |
| Common-Mode Input Range | Includes ground |
| Rail-to-Rail Input | Rail-to-rail |
| نوع الخرج | Open-collector/open-drain |
| Response Time | 300 ns |
| Logic Compatibility | TTL, MOS, and CMOS compatible |
| Industrial Grade | Industrial |
| Package Type | 8-pin SOIC |
| عدد الأطراف | 8 pins |
| نوع التركيب | Surface mount |
تكوين أطراف LM293AD
| دبوس 1 | OUT1 — Open-collector output for comparator channel 1 |
| دبوس 2 | IN1- — Inverting input for comparator channel 1 |
| دبوس 3 | IN1+ — Non-inverting input for comparator channel 1 |
| دبوس 4 | GND — Ground connection |
| دبوس 5 | IN2+ — Non-inverting input for comparator channel 2 |
| دبوس 6 | IN2- — Inverting input for comparator channel 2 |
| دبوس 7 | OUT2 — Open-collector output for comparator channel 2 |
| دبوس 8 | VCC — Positive supply connection |
التطبيقات النموذجية
LM293AD مناسب لـ 6 التطبيقs: Industrial Sensor Threshold Detection, Power-Supply Fault Detection, Battery Voltage Monitoring, Overvoltage and Reverse-Protection Logic, Relay and LED Status Control, Automotive Electrical-System Monitoring.
Industrial Sensor Threshold Detection
The LM293AD is suitable for converting an analog sensor signal into a binary threshold event because each channel compares a non-inverting input against an inverting input and includes ground within its common-mode input range. The 2 V to 36 V supply range supports higher-voltage industrial interfaces, while the approximately 300 ns response time handles rapidly changing sensor waveforms. Each open-collector output can pull a digital input low and requires an external pull-up resistor, allowing the interface to use a local TTL, MOS, or CMOS logic rail.
موصى به
Power-Supply Fault Detection
The LM293AD can monitor a power rail by comparing its voltage against a reference and changing the output state when the rail crosses the selected threshold. Its industrial grade, 2 V to 36 V supply capability, and common-mode operation down to ground make it useful in supply supervision and overvoltage or undervoltage indication. The approximately 300 ns response permits detection of fast transients, although circuit designers must observe the absolute-maximum input limits and use a suitable pull-up for the open-collector fault signal.
موصى به
Battery Voltage Monitoring
A pair of LM293AD channels can implement early and late battery-voltage thresholds, producing separate open-collector indications for an undervoltage and overvoltage condition. The common-mode input range includes ground, helping compare low battery voltages against a reference, and the 2 V to 36 V operating supply permits operation from elevated auxiliary rails. The external pull-up network should be selected for the intended logic system, while the differential input range of ±38 V requires careful transient protection at exposed battery terminals.
موصى به
Overvoltage and Reverse-Protection Logic
The LM293AD can compare a protected supply with a reference and assert an open-collector fault output when an abnormal voltage is detected. Its wide 2 V to 36 V operating range and differential input capability support protection systems operating above ordinary logic-supply levels. Because open-collector outputs sink current rather than source it, the fault signal can be pulled up to the system logic rail. Input clamping, divider tolerances, and the comparator response time should be considered together to prevent false trips during normal transients.
موصى به
Relay and LED Status Control
The LM293AD can generate a logic-controlled indication for a relay, LED, or alarm driver when an analog condition crosses a defined threshold. Its dual-channel architecture allows one input condition to control two related status functions, while the approximately 300 ns response supports prompt switching. A pull-up resistor is required on each open-collector output, and a separate transistor may be needed when the output must drive a load above the comparator's allowable sink current. LED polarity and relay-driver current should therefore be handled outside the comparator output.
موصى به
Automotive Electrical-System Monitoring
The LM293AD can monitor vehicle electrical signals because its operating supply range extends to 36 V and its common-mode input range includes ground. Two channels can supervise different system voltages or polarity conditions and provide open-collector fault outputs for a controller. Automotive use requires compliance review of the exact ordering variant, including temperature grade and automotive qualification, as well as protection from load dump and other transients. The basic LM293AD description does not by itself establish AEC-Q100 qualification.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ LM293AD — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | LM293ADR | LM293ADRE4 | LM393AD | LM2903AD | LM293AD |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics |
| Comparator Configuration | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator |
| Output Type | Open-collector/open-drain | Open-collector/open-drain | Open-collector/open-drain | Open-collector/open-drain | Open-collector/open-drain | Open-collector/open-drain |
أبرز الفروقات
- Maintains a wide 2 V to 36 V operating supply range (مقابلLM393AD)
- Provides approximately 300 ns response time (مقابلLM2903AD)
- Combines dual channels with open-collector fault outputs (مقابلLM293AD)
ملاحظات التصميم
Do not treat the ±38 V differential-input capability as permission to place ±38 V on every input pin. Check the individual input limits, supply configuration, common-mode range, and temperature conditions in the manufacturer datasheet. For exposed industrial or automotive nodes, add appropriate input attenuation or clamping so that normal operation and fault transients remain within the permitted limits.
Place each pull-up resistor close to the corresponding open-collector output so that the high-state trace remains short and has low capacitance. Keep the pull-up return and comparator ground on a low-impedance path, and route the two comparison channels to reduce shared high-current paths. A resistor value that is too high can slow the rising edge and create noise susceptibility, while one that is too low can exceed the output sink-current capability.
Use hysteresis or positive feedback when the compared signal can cross the threshold slowly or with noise. The LM293AD has approximately 300 ns nominal response time, but that does not prevent repeated output toggling from a noisy or slow-moving input. A small feedback network from output to the appropriate input establishes two switching levels and prevents chatter around the threshold.
The two comparator channels share supply pins, so their total supply-current demand must be included in the power budget and the PCB supply trace must be sized accordingly. Place the device bypass capacitor close to pin 8 and provide a short return to pin 4. Follow the manufacturer datasheet for the recommended capacitor value and layout because lead inductance can impair switching behavior if the supply loop is long.
معلومات الامتثال
The product information identifies LM293 as industrial grade but does not explicitly state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or AEC-Q100 status. Automotive qualification must not be assumed for the standard LM293AD.