LM293AM - Dual Differential Comparator, 36 V, SOIC-8 | onsemi
MPN: LM293AM ✓ ActiveLM293AM Overview
A differential comparator is an analog integrated circuit that compares two input voltages and changes its output state according to their relationship. The dual configuration provides two independent comparators in one package. When used with an external pull-up, an open-collector output can drive TTL, MOS, or CMOS-compatible circuitry while also allowing wired logic, level translation, or system reset behavior. The LM293AM belongs to the comparator hierarchy within amplifier and interface ICs.
Key features include single-supply operation to 36 V, dual-supply operation to ±18 V, a typical low-current drain of 800 µA, and a typical input bias current of 25 nA. The device can compare input voltages near ground potential and is compatible with multiple logic families. Its low input bias current helps reduce source-loading effects in high-impedance sensing networks, while the wide supply range supports industrial and automotive-style control environments.
The LM293AM uses open-collector outputs rather than push-pull outputs. This architecture provides a useful advantage when a comparator output must remain inactive until an external pull-up supplies the required logic-high voltage. It also supports open-wired signal arrangements, but every application must include the appropriate pull-up resistor and verify that the resulting rise time is acceptable. The operating common-mode range, differential input limits, output sink capability, and timing behavior should be checked against the manufacturer datasheet for the selected manufacturer version.
Typical applications include industrial control systems, power-supply supervision, motor and solenoid protection, battery monitoring, sensor-threshold conditioning, window or level detection, and general-purpose logic interfaces. The dual comparator arrangement is particularly useful when one circuit monitors two related thresholds or when an enable function and a fault signal can be implemented with the two channels in a compact footprint.
For PCB design, place the device so that sensitive input traces remain away from switching nodes and output pull-up routing. Keep input and output paths separate to reduce feedback through supply or board-level coupling. Confirm the logic-high level, output rise time, input common-mode range, supply decoupling requirements, and operating temperature range before releasing the design for production.
This page combines manufacturer-family operating limits, package details, sourcing guidance, replacement analysis, and practical PCB considerations to support faster component selection. Review the complete pin assignment and electrical characteristics in the LM293AM datasheet before layout, particularly when the same circuit must accommodate multiple LM293-family variants.
Drop-in alternatives for LM293AM — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LM293AM (same form factor and footprint) — differing in Logic Compatibility, Output Type, Package.
LM293AD
✅ Drop-InContact for price
View Datasheet →LM393AM
✅ Drop-InContact for price
View Datasheet →KA393ADTF
✅ Drop-In📋 Reference alternative (not in catalog)
LM293AM Maximum Ratings & Electrical Characteristics
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Single-Supply Operating Range | Up to 36 V |
| Dual-Supply Operating Range | Up to ±18 V |
| Typical Low Current Drain | 800 µA |
| Typical Input Bias Current | 25 nA |
| Output Type | Open-collector, open-drain |
| Common-Mode Input Capability | Comparison of voltages near ground potential |
| Logic Compatibility | Compatible with TTL, MOS, and CMOS logic |
| Package | 8-pin SOIC |
| Mounting Type | Surface mount |
LM293AM 8-pin soic Pin Configuration Guide
Pin configuration for LM293AM (8-pin soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for LM293AM.
Refer to the datasheet for full pin configuration.
Typical Applications
LM293AM is suitable for 6 applications: Industrial Threshold Monitoring, Motor Overcurrent Protection, Power-Supply Supervision, Battery Voltage Protection, Sensor Signal Conditioning, Logic Interface and Fault Latching.
Industrial Threshold Monitoring
The LM293AM fits industrial threshold-monitoring circuits because its two channels can independently compare process or supply voltages against reference limits. Single-supply operation to 36 V provides useful headroom for higher-voltage monitoring systems, while the typical 800 µA low-current drain reduces demand in unattended equipment. Use one channel for an upper threshold and the other for a lower threshold, add the required open-collector pull-ups, and verify that sensor and reference voltages remain within the comparator’s common-mode range. The compact 8-SOIC package also helps reduce board area in multi-channel control systems.
Recommended
Motor Overcurrent Protection
LM293AM can support motor overcurrent and fault detection when the shunt-derived signal and reference voltage fit the comparator’s input limits. The dual channels allow independent monitoring of two motor or power-stage conditions, while the open-collector output can pull up a fault input or inhibit a driver. Operation from a single supply up to 36 V makes the device useful in higher-voltage control architectures, but motor transients require careful filtering and protection. Confirm the differential-input limit, common-mode range, response time, and output sink current before using the comparator directly across an unclamped motor node.
Recommended
Power-Supply Supervision
The LM293AM is suitable for power-supply supervision where a divided rail voltage is compared with a reference and the fault signal must drive pulled-up logic. Its single-supply capability reaches 36 V, and the typical 25 nA input bias current reduces loading of high-impedance divider networks. The two channels can supervise positive and negative conditions independently. Place appropriate filtering at the divided input, select the pull-up voltage to match the receiving logic, and account for the open-collector output’s finite rise time when the fault signal must be captured quickly.
Recommended
Battery Voltage Protection
LM293AM can implement charge, discharge, or overvoltage protection by comparing a divided battery voltage against a reference. The single-supply range up to 36 V supports many low-voltage battery systems when the sensing network keeps the pin voltage within its limits, and the low typical input bias current helps preserve divider accuracy. Open-collector outputs can drive a charge-disable or fault indicator through suitable pull-ups. Validate the actual battery voltage range, transient protection, comparator offset, and temperature behavior rather than assuming the maximum supply rating applies to the input pins.
Recommended
Sensor Signal Conditioning
LM293AM can convert a slowly varying sensor signal into a logic event by comparing it with an adjustable threshold. Its typical 25 nA input bias current is useful when the sensing network has high source impedance, and the dual-channel configuration can handle two related signals or provide complementary threshold outputs. The open-collector result requires an external pull-up, allowing the output voltage to match the system’s logic level. Guard against input overvoltage, account for sensor noise through filtering or hysteresis, and verify the operating common-mode range across the full sensor excursion.
Recommended
Logic Interface and Fault Latching
The LM293AM can participate in wired fault indication and logic-interface circuits because each open-collector output can be pulled up to the voltage required by the receiving logic. Two channels are useful for monitoring separate conditions or forming complementary status signals, while the broad supply range supports multiple industrial rail arrangements. Pulled-up outputs permit wired logic where multiple fault sources share a node. Select a pull-up value that satisfies the receiver’s input current while meeting the required rise time, and ensure the output remains within its absolute-maximum and sink-current ratings during fault conditions.
Recommended
Recommended Products Summary
Engineering reference data for LM293AM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM293AD | LM393AM | KA393ADTF |
|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | Fairchild Semiconductor |
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Comparator Configuration | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual-channel comparator |
Key Differentiators
- Supports a higher single-supply operating ceiling (vs LM393AM)
- Lower typical input bias current supports high-impedance sensing (vs LM393AM)
- Dual differential channels in a compact 8-SOIC package (vs KA393ADTF)
Design Notes
Treat the open-collector outputs as pull-up nodes rather than actively driven push-pull outputs. Select the pull-up voltage to match the receiving TTL, MOS, or CMOS interface, and verify the resistor against both input current and the required output rise time. Ensure every pull-up remains within the comparator’s output-voltage limits. This is especially important in fault systems where a slow rising edge could delay acknowledgement or fault propagation.
Keep the two input nets for each differential comparator as short as practical and avoid routing them beside high-current switching nodes. Connect the device ground pins to a low-impedance ground plane and place supply-decoupling capacitance close to the supply and ground terminals. Because the comparator can operate near ground, inspect ground offsets and return-current paths carefully; a noisy reference ground can shift the effective comparison point and create false switching.
Do not assume that the 36 V single-supply rating makes every input safe at 36 V. Check the common-mode and differential-input limits in the exact manufacturer datasheet, add clamping where necessary, and distinguish supply pins from signal pins. Also confirm the temperature grade and offset requirements before substituting another LM293-family member. A shared footprint does not by itself guarantee equivalent limits, timing, or production qualification.
Compliance Information
No specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations were identified for LM293AM in the available manufacturer and distributor records.