LM219DT - High-Speed Dual Comparator | STMicroelectronics
Référence : LM219DT ✗ Fin de vieLM219DT Présentation
A comparator is an analog integrated circuit that compares two input voltages and changes its output state when the difference crosses a defined threshold. The LM219DT belongs to the broader comparator and linear-comparator hierarchy within integrated circuits. Its dual architecture allows one package to perform two independent comparisons, while the wide operating-voltage range supports both low-voltage logic systems and bipolar industrial circuits.
The principal features of the LM219DT include low input current, high gain, TTL-compatible outputs, and operation down to a single 5 V supply. These characteristics are useful when a sensing node has high source impedance, because the comparator must avoid loading the measured signal. The open-collector and open-emitter output structure also provides flexibility for level translation and wired-interface applications, although pull-up circuitry and output-state timing require careful review.
The device is intended for applications in industrial control, power management, signal conditioning, threshold detection, and digital-interface conversion. Its approximately 80 ns response can support pulse-width measurement, timing supervision, fast overvoltage detection, and switching-control loops. Unlike an analog amplifier, the LM219DT is intended primarily to make a fast binary decision rather than provide a continuously scaled analog output.
Designers should account for input common-mode range, output pull-up requirements, propagation-delay variation, and output sink-current capability before assigning the device. Because the outputs are open collector and open emitter, external pull-up or pull-down networks are normally required for conventional positive or negative logic levels. The manufacturer datasheet pin description and electrical characteristic tables should be used to verify each signal path and operating condition.
This product overview combines the manufacturer datasheet information with practical engineering guidance for comparing LM219DT implementations, planning logic-interface circuitry, and selecting a replacement when package, pinout, supply range, output architecture, and timing requirements all matter.
Alternatives de remplacement direct pour LM219DT — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec LM219DT (même facteur de forme et même empreinte) — différant par Package.
Aucune alternative de remplacement direct disponible pour ce produit.
Demander des alternativesLM219DT Valeurs maximales et caractéristiques électriques
| Comparator Type | General-purpose dual voltage comparator |
| Number of Comparators | 2 comparators |
| Configuration de sortie | Open-collector, open-emitter |
| Logic Compatibility | TTL-compatible |
| Minimum Supply Voltage | 5 V |
| Maximum Supply Voltage | Approximately 30 V total supply |
| Bipolar Supply Configuration | Approximately ±15 V |
| Propagation Delay | Approximately 80 ns |
| Boîtier | 14-pin SO surface-mount package |
| Type de montage | Surface mount |
| Shipping Format | Tape and reel |
Guide de configuration des broches du LM219DT 14-pin so surface-mount package
Configuration des broches du LM219DT (boîtier 14-pin so surface-mount package). Ce composant analogique comporte des broches d'entrée, de sortie et d'alimentation. Consultez la fiche technique du fabricant pour les configurations des broches d'annulation d'offset, de compensation et d'activation. Idéal pour le conditionnement de signaux et les circuits amplificateurs.
Aucune donnée de brochage détaillée disponible pour LM219DT.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
LM219DT convient pour 6 applications: Industrial Threshold Detection, Power-System Overvoltage Detection, Pulse-Width and Timing Supervision, High-Impedance Sensor Interface, Digital Interface Level Translation, Fast Control-Loop Decision.
Industrial Threshold Detection
The LM219DT is useful in industrial threshold-detection circuits where an analog process or sensor signal must be converted into a fast logic decision. Its two independent comparator channels can monitor two limits or two stages within one 14-pin package. The approximately 80 ns propagation delay allows the decision to occur promptly, while low input current helps prevent the comparator from significantly loading a high-impedance sensing node. In a practical implementation, each channel compares the monitored voltage with a reference and drives a pull-up or pull-down network. The designer must verify the input common-mode range at the actual signal level, select resistor values that provide adequate logic rise time, and ensure the output load remains within the sink-current limit. For industrial equipment, the assembled system should also confirm the device temperature grade and environmental qualification requirements.
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Power-System Overvoltage Detection
The LM219DT can supervise a power rail by comparing a scaled voltage against a reference and generating a fault signal when the monitored level crosses the selected threshold. Its high-speed response is valuable when the system must respond quickly to an abnormal condition, and the dual-channel configuration allows two rails or two thresholds to be monitored. The comparator is normally placed between a resistor-divider sensing network and the system fault logic, with the output configured through a pull-up or pull-down network. Because the LM219DT is not being used as a continuous power regulator, the key design issue is detection accuracy and response timing. Verify that the sensing-node voltage remains inside the input common-mode range during normal operation and during transients, and ensure the selected external network does not create excessive delay or unwanted power consumption.
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Pulse-Width and Timing Supervision
The LM219DT is well suited to pulse-width, edge-timing, and event-duration monitoring because its approximately 80 ns propagation delay supports fast logic decisions. A timer or pulse source can be compared with a reference waveform to generate an early-warning or timeout indication. In such designs, the open-collector and open-emitter outputs provide flexibility for wired logic and level conversion, but external pull-up or pull-down resistors are required to establish valid logic states. The timing budget must include comparator propagation delay, reference-network delay, resistor rise time, and load capacitance. The system designer should also examine delay variation across operating temperature and input overdrive because a nominal 80 ns value does not represent the complete worst-case path. Pull-up resistance should be low enough to meet the required edge rate while remaining within the output transistor's sink-current capability.
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High-Impedance Sensor Interface
The LM219DT can provide a clean logic threshold at the output of a high-impedance sensor or conditioning network without heavily loading the sensed node. Its low input-current characteristic is the key benefit in this application: the source network sees less unwanted loading, helping preserve the amplitude and timing of the measured signal. The comparator can drive an enable, alarm, interrupt, or direction input after the signal crosses the chosen reference. Application design should minimize leakage paths around the input pins and keep sensitive traces away from fast output and supply-return paths. The input common-mode range must cover the complete sensor-output excursion, including tolerances and overshoot, while the reference should remain stable over the required temperature range. If the sensor signal changes slowly, add hysteresis with feedback around the selected channel to prevent repeated output transitions near the threshold.
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Digital Interface Level Translation
The LM219DT can translate a voltage-domain indication into a logic-domain signal by comparing one polarity against a reference and using the complementary open-collector and open-emitter outputs. This arrangement is useful when a sensor, protection circuit, or older logic block must communicate with a system using a different voltage reference. The open output devices allow the final logic levels to be established by external pull-up or pull-down resistors rather than fixed internal voltage levels. During implementation, verify that both input signals remain within the comparator's supported common-mode range and that the output transistors can sink the pull-up current required by the receiving logic. The external resistor should also produce an acceptable rise time at the bus capacitance. For bidirectional or multi-source interfaces, additional arbitration or contention controls may be required beyond the basic LM219DT output structure.
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Fast Control-Loop Decision
The LM219DT can support fast control decisions in industrial and power-control subsystems where a sampled voltage must be compared with a command or feedback level. Its high-speed response shortens the interval between crossing the threshold and changing the output state, which is important in cycle-by-cycle control, protection, and feedback paths. The comparator should be treated as the decision element rather than as an analog amplifier, with the surrounding control loop defining its reference and feedback network. Design work should account for propagation-delay variation, output transition time, and the time required for downstream circuitry to react. A small amount of hysteresis can improve stability around the comparison threshold, while keeping the feedback network from increasing excessive input capacitance. The exact output pull-up or pull-down network must also preserve valid levels at the connected controller and remain within the comparator's output-current limits.
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Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LM219DT — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit |
|---|---|
| Comparator Type | General-purpose dual voltage comparator |
| Number of Channels | 2 |
| Propagation Delay | Approximately 80 ns |
| Supply Range | Single 5 V to approximately ±15 V |
| Output Configuration | Open-collector, open-emitter |
| Logic Compatibility | TTL-compatible |
| Package | 14-pin SO surface-mount package |
| Brand | STMicroelectronics |
Notes de conception
Do not treat an open-collector output as a push-pull logic output. Use the manufacturer pin-description table to identify the open-collector and open-emitter channels, then place the appropriate external pull-up or pull-down network on each signal used by the system. Check the resistor against both the required logic rise time and the output transistor's maximum sink current; a lower pull-up resistance improves edge speed but increases current when the output is active.
Keep comparator input and feedback traces short, place the input network close to the device, and route them away from output, supply, and clock-switching nodes. The LM219DT's low input current reduces loading, but board leakage and nearby high-impedance traces can still corrupt a sensitive threshold. Connect the device ground and supply-return paths carefully, use a local bypass capacitor at the supply pins, and avoid sharing narrow return paths with high-current switching outputs.
Budget the complete switching path rather than only the approximately 80 ns nominal comparator delay. Include output rise or fall time, pull-up or pull-down resistance, receiver input capacitance, reference-node settling, and delay variation over temperature and input overdrive. If repeated transitions occur around the threshold, add controlled hysteresis and verify that the feedback network does not move the effective threshold beyond the required accuracy.
Validate the selected positive and negative supply configuration against the manufacturer's absolute-maximum and operating limits, including total supply voltage, common-mode input range, and output current. Place a supply bypass capacitor close to the device and keep the return path short. When the circuit uses bipolar supplies, establish the ground reference correctly and verify that all connected logic devices tolerate the resulting output levels.
Informations de conformité
The manufacturer datasheet describes the LM219 family and its electrical characteristics. Specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals declarations require confirmation from the current manufacturer product documentation or declaration.
