LM393AM - Dual 36V Differential Comparator | onsemi | SOIC-8
N.º de pieza: LM393AM ✓ ActivoLM393AM Descripción general
A differential comparator is an integrated circuit that evaluates the relationship between two voltages and translates the result into a logic-level output. The LM393 belongs to the comparator hierarchy within analog and mixed-signal semiconductors, where it sits alongside amplifiers, voltage references, logic interfaces, and other power-management functions. Its open-collector architecture is particularly useful when a designer needs to combine outputs, control a wired bus, or interface to legacy TTL and CMOS logic.
The LM393AM provides two independent comparator channels in one package. Operation from a single supply allows the common-mode input range to approach ground, making the part useful for battery-powered monitoring, sensor conditioning, window comparison, and supply-control circuits. An open-collector output requires an external pull-up resistor because the output transistor actively pulls the output toward ground but does.source current from the output. This feature permits wired logic operation when several outputs share a bus and allows the output polarity to be changed by assigning the pull-up to either the positive or negative supply.
The principal engineering trade-off is low power consumption versus modern performance. The 800 µA typical current drain suits battery-operated equipment, while the 25 nA typical input bias current helps preserve accuracy with high-impedance sensing networks. Because the output is open collector, designers must verify pull-up resistance, pull-up voltage, rise time, output sink current, and system-level timing rather than treating the part like a push-pull logic gate.
Typical applications include overvoltage and undervoltage protection, battery monitoring, thermistor and light sensor interfaces, motor or actuator threshold detection, industrial control modules, and embedded logic. In each case, the LM393AM converts a small analog differential into a digital decision. The commercial-temperature LM393AM should be selected where its specified temperature range, supply limits, offset behavior, and propagation delay satisfy the design.
For PCB implementation, place the decoupling capacitor close to the supply and ground pins, keep input traces short, and provide adequate copper for heat dissipation. The open-collector output node can be sensitive to capacitive loading and leakage, so external pull-up placement and grounding require careful review. This page combines verified source data, package-level alternatives, parameter comparisons, and application guidance to support practical component selection without relying on the datasheet alone.
Alternativas directas para LM393AM — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con LM393AM (mismo factor de forma y huella) — difiere en Number of Channels, Output Type, Package, RoHS Status.
LM393DR
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →LM393ADR
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LM2903DR
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LM393AMN
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2903DR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TLV1702-Q1
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM393AM Valores máximos y características eléctricas
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Single-Supply Operating Voltage | 36 V maximum |
| Dual-Supply Operating Voltage | ±18 V maximum |
| Current Drain | 800 µA typical |
| Input Bias Current | 25 nA typical |
| Tipo de salida | Open collector |
| Logic Compatibility | Compatible with all forms of logic |
| Ground-Level Comparison | Supported |
| Encapsulado | 8-SOIC |
| Package Width | 3.90 mm (0.154 inch) |
| Tipo de montaje | Surface mount |
| Estado RoHS | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | not_applicable |
Configuración de pines de LM393AM
| Pin 1 | OUT1 — Comparator 1 open-collector output |
| Pin 2 | IN-1 — Comparator 1 inverting input |
| Pin 3 | IN+1 — Comparator 1 non-inverting input |
| Pin 4 | GND — Ground connection |
| Pin 5 | IN+2 — Comparator 2 non-inverting input |
| Pin 6 | IN-2 — Comparator 2 inverting input |
| Pin 7 | OUT2 — Comparator 2 open-collector output |
| Pin 8 | VCC — Positive supply connection |
Aplicaciones típicas
LM393AM es adecuado para 6 aplicacións: Battery Voltage Monitoring, Industrial Sensor Interfacing, Overvoltage Protection, Temperature and Light Thresholding, Motor and Actuator Control, Open-Collector Logic Interfacing.
Battery Voltage Monitoring
The LM393AM fits battery-pack threshold detection because its single-supply operation extends to 36 V and its 800 µA typical current drain limits quiescent consumption. Place the comparator in the divider that compares a scaled battery voltage against a reference, then use the open-collector output to signal an overvoltage or undervoltage event. The 25 nA typical input bias current is useful when the divider has high impedance, although resistor tolerance and temperature drift still determine threshold accuracy. An external pull-up is required because the output cannot source current.
Recomendado
Industrial Sensor Interfacing
LM393AM is useful for industrial sensor interfaces that compare a slowly changing analog signal with a threshold close to ground. Its dual differential architecture permits two independent measurements in one 8-SOIC package, while 25 nA typical input bias current reduces loading of resistive or high-impedance sensor networks. The open-collector output can drive an alert, relay-driver input, or digital isolator enable. Designers must check the input common-mode range, output pull-up voltage, propagation delay, and noise margin for the particular sensor and industrial temperature environment.
Recomendado
Overvoltage Protection
The LM393AM can implement fast overvoltage detection in a power module by comparing a scaled supply voltage with a reference. Its capability to operate from a single supply up to 36 V supports systems with elevated internal rails, while the open-collector output provides a fail-safe indication that defaults to the pulled-up state when the comparator is unpowered. The design must account for the output pull-up's logic level, the comparator's propagation delay, input protection requirements, and any differences between the target part and an LM2903-family alternative.
Recomendado
Temperature and Light Thresholding
LM393AM supports thermistor, phototransistor, and other analog threshold systems that require a simple digital decision rather than a linear amplified output. One channel can monitor a temperature-derived voltage and the other can monitor a light sensor, provided both signals remain inside the input common-mode range. The 800 µA typical current drain is useful in portable equipment, while the 25 nA typical input bias current reduces disturbance of high-value dividers. Hysteresis can be added with positive feedback, and an open-collector pull-up provides the required logic-high state.
Recomendado
Motor and Actuator Control
LM393AM can supervise actuator drive signals by comparing a command or feedback voltage with a limit. The open-collector output is useful for driving a shutdown input, fault flag, or relay-logic stage, and the device can evaluate signals near ground in single-supply systems. With two channels, one side may detect an upper threshold while the other detects a lower threshold, creating a control window. Because open-collector outputs can be wired together, multiple conditions can share a fault line, but the designer must verify that every attached output can tolerate the shared sink current.
Recomendado
Open-Collector Logic Interfacing
LM393AM suits legacy logic and bus designs where an open-collector output is required rather than a push-pull CMOS output. The pulled-up output can remain compatible with multiple open-collector devices on the same node, and the part's stated compatibility with all forms of logic simplifies interfacing to TTL and CMOS systems. The pull-up resistor establishes the high-state voltage and rise time, so it must be calculated using the output leakage, attached-device leakage, bus capacitance, and required switching speed. Because the output only sinks current, system reset and fault signals should not depend on source capability.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LM393AM — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LM393DR | LM2903DR | LM393AMN | LM2903DR | TLV1702-Q1 |
|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| 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 collector | Open collector | Open collector | Open collector | Open collector |
Diferenciadores clave
- Low quiescent current supports portable monitoring systems (frente a LM393AMN)
- Wide single-supply operating range (frente a TLV1702-Q1)
- Ground-potential input comparison (frente a LM2903DR)
- Two independent open-collector channels in SOIC-8 (frente a LM393DR)
Notas de diseño
The LM393AM output is open collector, so a pull-up resistor is mandatory. Do not assume that OUT1 or OUT2 can source a logic-high current. Calculate the pull-up from the required logic-high voltage, maximum sink current, leakage from every attached device, and allowable rise time. If multiple open-collector outputs share a node, verify that their combined sink-current capability remains sufficient under the worst-case condition.
Place the supply bypass capacitor close to pin 8 and the ground return close to pin 4 to minimize supply-loop impedance. Keep the IN+ and IN− traces away from the output and pull-up node because the output edge can capacitively couple into the inputs. If the comparator drives a long or high-impedance trace, terminate it appropriately and consider a small pull-up value consistent with the required sink-current and power limits.
Although the verified source gives 800 µA typical current drain, total power also includes the pull-up network and any external logic load. Do not operate beyond the manufacturer's 36 V single-supply or ±18 V dual-supply limits. For higher-voltage systems, add appropriately rated protection and confirm that the actual input common-mode range remains valid at every operating corner.
Información de cumplimiento
The supplied verified snippets do not explicitly establish target-part RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is marked not_applicable because the verified data identifies LM393AM as a commercial-grade general-purpose comparator rather than an automotive-qualified device.
