LM393DR - Dual Differential Comparator SOIC-8 | Texas Instruments
MPN: LM393DR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.25 | $0.25 |
| 10 | $0.19 | $1.90 |
| 100 | $0.13 | $13.00 |
| 500 | $0.1 | $50.00 |
| 1,000 | $0.08 | $80.00 |
Drop-in alternatives for LM393DR β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LM393BIDR
β Drop-Inπ Reference alternative (not in catalog)
LM2903IDR
β Drop-Inπ Reference alternative (not in catalog)
LM393ADR
β Drop-Inπ Reference alternative (not in catalog)
LM393DR2G
β Drop-Inπ Reference alternative (not in catalog)
LM393DT
β Drop-Inβ In Stock
$0.0461 / Unit
View Datasheet βLM393DR
β Drop-Inβ In Stock
$0.08 / Unit
View Datasheet βLM393DR Maximum Ratings & Electrical Characteristics
| Number of Comparators | 2 |
| Type | Differential Comparator, General Purpose |
| Output Type | Open-Collector, Rail-to-Rail |
| Supply Voltage Range (Single) | 2 V to 36 V |
| Supply Voltage Range (Dual) | +/-1 V to +/-18 V |
| Input Offset Voltage (Typical) | 1 mV |
| Input Offset Voltage (Max) | 5 mV |
| Input Bias Current | 25 nA (typical) |
| Supply Current (Per Comparator) | 0.4 mA (typical) |
| Response Time | 1.3 us (typical) |
| Common-Mode Input Range | V- to VCC - 1.5 V |
| Output Sink Current | 20 mA |
| Operating Temperature Range | 0C to +70C |
| Package | SOIC-8 (D) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
LM393DR Pin Configuration
| Pin 1 | OUT1 β Output of comparator 1 (open-collector, requires pull-up) |
| Pin 2 | IN1- β Inverting input of comparator 1 |
| Pin 3 | IN1+ β Non-inverting input of comparator 1 |
| Pin 4 | GND / V- β Ground or negative supply |
| Pin 5 | IN2+ β Non-inverting input of comparator 2 |
| Pin 6 | IN2- β Inverting input of comparator 2 |
| Pin 7 | OUT2 β Output of comparator 2 (open-collector, requires pull-up) |
| Pin 8 | VCC / V+ β Positive supply, 2 V to 36 V |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LM393DR is suitable for 6 applications: Voltage Level Detection, Battery Undervoltage Monitoring, Zero-Crossing Detection, Oscillator and Square-Wave Generation, Power Supply Supervisory Circuits, Sensor Threshold Detection in IoT Nodes.
Voltage Level Detection
The LM393DR is the classic choice for threshold detection because its common-mode input range extends to ground, allowing direct comparison of ground-referenced signals against a reference divider. With 1 mV typical offset, it resolves millivolt-level thresholds, and its open-collector output interfaces to any logic rail up to 36V via a pull-up. Two independent comparators in one SOIC-8 enable upper and lower limit monitoring in a single footprint, cutting BOM cost below $0.25 as of 2026-08-29.
Recommended
Battery Undervoltage Monitoring
In battery-powered systems, the LM393DR's 0.4 mA per-comparator quiescent current preserves battery life while continuously monitoring cell voltage. The supply range of 2V to 36V covers single-cell lithium to multi-cell lead-acid stacks. One comparator monitors undervoltage with a resistor divider against an internal bandgap reference; the second can implement a latching shutdown. Hysteresis of tens of millivolts via positive feedback prevents output chatter as the battery hovers near the trip point.
Recommended
Zero-Crossing Detection
The LM393DR detects AC zero-crossings by comparing a scaled mains-derived signal against ground - enabled by its ground-sensing PNP input stage. The 1.3 us typical response time is more than adequate for 50/60 Hz timing, and the open-collector output safely interfaces to microcontroller interrupts through a pull-up. Used in triac dimmers, solid-state relays, and synchronous switching power supplies, it provides the timing reference that minimizes switching transients and EMI.
Recommended
Oscillator and Square-Wave Generation
With positive feedback around one comparator and an RC network on the input, the LM393DR forms a relaxation oscillator generating square waves from a few Hz to roughly 100 kHz. The second comparator remains available for level detection or a duty-cycle control input. This topology is used for clock sources, tone generation, PWM carriers, and LED blinkers. Supply current stays under 1 mA for the whole function, and the open-collector output swings cleanly to any logic level via the pull-up.
Recommended
Power Supply Supervisory Circuits
The LM393DR supervises multiple power rails: one comparator tracks a 3.3V/5V rail against a precision reference while the second monitors a second rail for sequencing or fault reporting. Its 36V maximum supply tolerates industrial 24V buses, and outputs wired-OR together to a single microcontroller fault input. The 0C to +70C rating suits commercial and industrial indoor equipment. Pairing with TI references such as the REF3030 achieves sub-1% trip-point accuracy over temperature.
Recommended
Sensor Threshold Detection in IoT Nodes
In battery-operated IoT sensors, the LM393DR converts analog sensor outputs - LDRs, NTC thermistors, gas sensor bridges - into clean digital alerts without waking the MCU. With 0.4 mA consumption and 2V operation, it runs directly from a dying coin cell. The ground-sensing inputs read low-side sensor dividers directly, and comparator outputs can gate the MCU wake pin. This offloads threshold logic from software, reducing firmware complexity and average system current draw significantly.
Recommended
Recommended Products Summary
Engineering reference data for LM393DR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM393BIDR | LM2903IDR | LM393DR2G | LM393D | LM393DR (ROHM) |
|---|---|---|---|---|---|---|
| Package | SOIC-8 (D) | SOIC-8 (D) - same | SOIC-8 (D) - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | STMicroelectronics | ROHM Semiconductor |
| Supply Voltage Range | 2 V to 36 V | 2 V to 38 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V |
| Input Offset Voltage (Max) | 5 mV | 2 mV (typ 0.37 mV) | 9 mV | 9 mV | 9 mV | [DATA_NEEDED] |
| Response Time (Typical) | 1.3 us | 1 us | 1.3 us | 1.3 us | 1.3 us | [DATA_NEEDED] |
| Operating Temperature | 0C to +70C | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +85C | [DATA_NEEDED] |
| Automotive Grade | No | No (industrial temp) | Yes (AEC-Q100 family) | No | No | No |
| ESD Rating (HBM) | [DATA_NEEDED] | 2 kV | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- Lowest cost per comparator (vs TLV3501)
- Improved precision and speed available at same footprint (vs LM393BIDR)
- Multi-vendor second sourcing (vs LM393D (ST) / LM393DR2G (onsemi))
Design Notes
Never leave the LM393 open-collector outputs unterminated - they cannot source current and will float unpredictably. Fit a pull-up resistor (1 kOhm to 100 kOhm) from each output to the target logic rail, which may be a different voltage than VCC up to 36V. Forgetting this is the single most common first-use failure, since the comparator appears dead on the bench.
Add hysteresis to every comparator used with slow-moving or noisy analog signals. A 100 kOhm to 1 MOhm feedback resistor from output to the non-inverting input creates a few millivolts of deadband, eliminating output chatter near the threshold. Also add a 0.1 uF ceramic decoupling capacitor directly across pins 8 and 4, and keep input traces short to reduce susceptibility to coupled noise.
The LM393 inputs can be taken below ground by small negative transients without damage, but sustained input voltages more negative than -0.3V exceed absolute maximum ratings - protect inputs with series resistors or clamp diodes in mains-sensed circuits. For differential sensing across a shunt, route the two input traces as a tightly coupled pair to reject common-mode noise, a layout practice emphasized in TI analog application notes.
Compliance Information
RoHS compliant per DigiKey product listing. AEC-Q100 not applicable to standard LM393; use LM2903 for automotive grade.
