LM2901M - 4-Channel 36V Open-Collector Comparator | Texas Instruments
MPN: LM2901M ✓ نشطLM2901M نظرة عامة
An analog comparator is a semiconductor that converts the relationship between two voltages into a logic-level output. The LM2901 belongs to the comparator hierarchy, where a general-purpose comparator is used for threshold detection, signal conditioning, and industrial control rather than precision analog amplification. Its wide supply range, low input bias current, and low typical supply-current consumption make it suitable for systems operating from low-voltage control circuits through higher-voltage industrial environments.
The principal features include four independent comparator channels, an approximate 36 V maximum supply, 800 µA typical supply-current drain, 25 nA typical input bias current, and open-collector outputs suitable for wired logic. These characteristics allow the device to monitor slow and fast control signals while maintaining low loading on high-impedance sensor nodes. The open-collector architecture also supports wired-AND behavior when multiple comparators share a pull-up resistor, although the common output node requires careful voltage and timing analysis.
Each internal comparator has an inverting input, a non-inverting input, and an open-collector output. The open-collector transistor normally remains off, so an external pull-up resistor is required to establish a high output state. When the comparator output is pulled low, the output transistor sinks current from that pull-up network. The resulting interface can support wired logic, relay-driver stages, lamp indicators, and other systems where a pulled-up bus must be shared safely.
Typical applications include industrial sensor-limit detection, overvoltage and undervoltage monitoring, battery threshold detection, control-system interlock circuits, and logic-level translation around higher-voltage signals. The four channels can be used independently, or several channels can implement window comparison, fault detection, and redundant monitoring functions. A common ground and supply arrangement simplifies multi-channel designs while requiring attention to common-mode limits, output pull-up placement, and input protection.
The principal design consideration is ensuring that input and output conditions remain within the comparator's absolute maximum and common-mode limits. Input protection may be required when external wiring exposes the device to transients or voltages outside the normal operating range. The open-collector outputs also need suitable pull-up resistors, with resistance selected from the required sink-current, rise-time, and bus-loading constraints rather than from resistance alone.
This page combines manufacturer specifications, verified distributor information, pin-level implementation guidance, and same-footprint replacement analysis. It also identifies the practical trade-offs among closely related LM2901-family ordering options so that engineers can distinguish electrical compatibility, package identity, and qualification differences before committing a design to production.
بدائل مباشرة لـ LM2901M — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع LM2901M (نفس عامل الشكل والبصمة) — يختلف في Comparator Type, Package, Number of Channels, Output Compatibility.
LM2901DR
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM2901MX
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM2903M
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LM239DR
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LM2901M/NOPB
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LM2901M الحدود القصوى والخصائص الكهربائية
| Comparator Type | 4-channel differential analog comparator |
| Number of Channels | 4 channels |
| Single-Supply Operating Voltage Range | 2 V to 36 V |
| Dual-Supply Operating Voltage Range | Approximately ±1 V to ±18 V |
| Typical Response Time | 1.3 µs |
| نوع الخرج | Open-collector |
| Typical Supply Current Drain | 800 µA |
| Typical Input Bias Current | 25 nA |
| Typical Input Offset Voltage | 7 mV |
| Output Low-Level Compatibility | Compatible with TTL, MOS, and CMOS logic |
| العلبة | 14-pin SOIC |
| نوع التركيب | Surface Mount |
| حالة RoHS | Compliant |
| Operating Principle | Single-supply or dual-supply operation |
تكوين أطراف LM2901M
| 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 reference |
| 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 | OUT3 — Open-collector output for comparator channel 3 |
| دبوس 9 | IN3- — Inverting input for comparator channel 3 |
| دبوس 10 | IN3+ — Non-inverting input for comparator channel 3 |
| دبوس 11 | VCC — Positive supply input |
| دبوس 12 | IN4+ — Non-inverting input for comparator channel 4 |
| دبوس 13 | IN4- — Inverting input for comparator channel 4 |
| دبوس 14 | OUT4 — Open-collector output for comparator channel 4 |
التطبيقات النموذجية
LM2901M مناسب لـ 6 التطبيقs: Industrial Sensor Threshold Detection, Battery Overvoltage and Undervoltage Monitoring, Control-System Interlock and Fault Logic, Open-Collector Logic Interface and Level Translation, Motor and Solenoid Drive Sequencing, Analog Signal Crossing and Pulse Conditioning.
Industrial Sensor Threshold Detection
The LM2901M fits industrial sensor monitoring because four independent channels can compare each sensor signal against a reference or adjustable threshold. Its 25 nA typical input bias current places little demand on high-impedance sensing nodes, while the 2 V to 36 V operating range supports both low-voltage control electronics and higher-voltage industrial interfaces. Place the appropriate reference on the inverting or non-inverting input according to the desired switching action, then use the open-collector output with a pull-up resistor to drive an alarm, PLC input, or relay-driver stage. Long external cables should be protected against transients because the comparator inputs can be exposed to more severe conditions than the nominal signal.
موصى به
Battery Overvoltage and Undervoltage Monitoring
The LM2901M can monitor battery-derived rails in single-supply systems operating across the 2 V to 36 V range. Individual comparator channels may detect upper and lower thresholds, creating a window monitor when their references and logic polarity are coordinated. The low typical input bias current of 25 nA helps reduce error when the monitored node has relatively high source impedance, while the 800 µA typical supply-current drain keeps comparator overhead modest. Use suitable input dividers and protection networks, and select pull-up values that satisfy the required alarm rise time without overloading the open-collector output during a fault condition.
موصى به
Control-System Interlock and Fault Logic
The LM2901M is suitable for multi-condition interlock logic because each channel compares one control voltage against another independently. Its 1.3 µs typical response time is appropriate for general industrial control tasks rather than precision timing, and the open-collector outputs permit several fault signals to share a wired-AND bus. The common output pull-up must be selected so that the worst-case combined sink current remains within the channel limit and the bus transitions quickly enough for the receiving controller. Separate pull-up branches can isolate faults and simplify diagnostics, particularly when one channel may remain active indefinitely after a machine shutdown.
موصى به
Open-Collector Logic Interface and Level Translation
The LM2901M can translate a higher-voltage control signal into an open-collector logic level when the receiving circuit requires a pulled-up bus. The output supports wired logic, and its 36 V maximum supply allows operation near a broader industrial voltage range than many low-voltage comparators. Connect the pull-up resistor to the voltage required by the receiving TTL, MOS, or CMOS input rather than automatically using the comparator supply. Check the receiving device's input-current limits and the comparator's output leakage and sink-current ratings. The resulting circuit is simpler than a general-purpose bidirectional level translator when only a unidirectional threshold indication is required.
موصى به
Motor and Solenoid Drive Sequencing
The LM2901M can supervise motor-control or solenoid-control signals and provide a fault indication before an external driver is enabled. The four channels permit separate checks of position sensors, supply-derived thresholds, or control-command states. Its 1.3 µs typical response is generally sufficient for ordinary sequencing decisions, while the wide supply range permits operation in 12 V, 24 V, and similar industrial systems when signal amplitudes remain compliant. The open-collector output should drive a suitable logic input or gate stage rather than the solenoid directly. Include flyback protection on inductive loads and use the comparator as supervisory logic rather than the primary high-current switching element.
موصى به
Analog Signal Crossing and Pulse Conditioning
The LM2901M can convert an analog crossing into a logic event for pulse shaping, event counting, or control-system isolation. Its 25 nA typical input bias current and 7 mV typical offset are suitable for many general-purpose sensor and waveform-conditioning tasks. The 1.3 µs response time allows the open-collector output to follow moderate-speed crossings without acting as a precision high-speed comparator. Add hysteresis around the switching threshold to prevent repeated output transitions from slow or noisy signals. The external pull-up resistor and any downstream capacitance set the output rise time, so the complete delay should be checked against the pulse width being measured.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ LM2901M — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | LM2901DR | LM2901MX | LM2903M | LM239DR | LM2901M/NOPB |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Fairchild Semiconductor | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 14-pin SOIC | 14-pin SOIC - same | 14-pin SOIC - same | 14-pin SOIC - same | 14-pin SOIC - same | 14-pin SOIC - same |
| Comparator Channels | 4 channels | 4 channels | 4 channels | 4 channels | 4 channels | 4 channels |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
أبرز الفروقات
- Lower typical supply current than the identified Fairchild alternative (مقابلLM2901MX)
- Wider listed maximum supply than LM239DR (مقابلLM239DR)
- Direct same-family ordering option preserves the original electrical design (مقابلLM2901M/NOPB)
- No PCB change required for the LM2903M alternative (مقابلLM2903M)
ملاحظات التصميم
Do not connect the open-collector outputs directly to a supply rail. Each output requires an external pull-up resistor because the output transistor only sinks current. Choose the pull-up voltage for the receiving logic level and calculate worst-case sink current, output leakage, and bus rise time. When several channels share one pull-up node, confirm that the combined fault-state sink current remains below the absolute maximum and that the resulting wired-AND delay is acceptable.
Place the supply bypass capacitor and any input or output protection components close to the LM2901M pins. Route the four comparator inputs away from switching nodes, relay contacts, and high-current return paths to reduce differential noise pickup. Keep the ground return compact and use the same ground reference for the input network, supply decoupling, and downstream logic. A grounded guard or physical separation around high-impedance input traces can improve threshold repeatability in industrial environments.
Add intentional hysteresis when the input crosses a threshold slowly, because output chatter can cause repeated counter increments or relay chatter. A positive-feedback resistor from the appropriate output to the non-inverting input creates hysteresis, while a resistor from the output to the inverting input provides a negative-feedback threshold arrangement. Account for the open-collector output's finite rise time when the threshold signal is fast or the downstream device requires a sharply defined pulse edge.
Estimate comparator dissipation from the actual supply voltage and total channel current rather than assuming the 800 µA typical figure applies in every state. The estimated value is the supply voltage multiplied by measured or calculated device current, including pull-up current that flows when an output transistor is off. Verify the result against the absolute maximum ratings and the device temperature range. A low-power design should also minimize the pull-up resistance where a slower bus edge is acceptable.
معلومات الامتثال
RoHS compliance is identified for LM2901M and LM2901DR. AEC-Q100 qualification is not established for the exact LM2901M ordering code; the generic family page describes B-version improvements but does not establish qualification for LM2901M. Other environmental and material compliance fields remain unknown.