LM293D - Dual Differential Comparator, 8-SOIC | TI
MPN: LM293D ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.29 | $0.29 |
| 10 | $0.25 | $2.50 |
| 100 | $0.18 | $18.00 |
| 500 | $0.14 | $70.00 |
| 1,000 | $0.11 | $110.00 |
LM293D Overview
A comparator is an analog signal-conditioning IC that compares two input voltages and produces a logic-level output indicating which input is higher. A differential comparator belongs to the broader comparator, amplifier, and analog interface hierarchy, while the LM293D is specifically a low-power, dual-channel comparator for embedded and control applications. Its two independent channels allow simultaneous comparison of two signal pairs, provided the device operates within the manufacturer-rated common-mode and supply limits.
The verified TI page states that the LM293 family supports wide supply-voltage operation, including systems using split power supplies. TI also states that the B-version is a drop-in replacement for LM293, LM393, and LM2903; however, the provided data does not establish that every related suffix is electrically identical for every use condition. The LM293D listing identifies open-collector/open-drain and rail-to-Rail output characteristics, which are important when interfacing with pull-up-based digital systems.
Typical uses include monitoring a battery or power rail, detecting sensor thresholds, comparing external reference voltages, and implementing basic overvoltage or undervoltage indication. The open-drain output requires an external pull-up resistor when the output must rise to a defined logic level. Because the verified data does not provide exact input-offset, response-time, supply-current, or temperature values, those specifications are retained as data-needed markers rather than inferred from related devices.
For PCB design, place the IC close to the compared signals and use short, low-noise routing for high-impedance input nodes. Keep pull-up resistors close to open-drain outputs, and account for input common-mode range and supply polarity in both single-supply and split-supply systems. The LM293D is not a power semiconductor, so SOA data is not applicable.
Drop-in alternatives for LM293D — 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 LM293D (same form factor and footprint) — differing in Output Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LM393D
✅ Drop-In✓ In Stock
$0.11 / Unit
View Datasheet →LM2903D
✅ Drop-In📋 Reference alternative (not in catalog)
LM293D
✅ Drop-In✓ In Stock
$0.11 / Unit
View Datasheet →LM293D Maximum Ratings & Electrical Characteristics
| Product Type | Dual differential comparator |
| Comparator Configuration | Two independent comparators |
| Output Type | Open-collector, open-drain |
| Common-Mode Characterization | Rail-to-rail |
| Supply Configuration | Single supply or split supply |
| Package | 8-SOIC |
| Mounting Type | Surface mount |
| Pin Count | 8 pins |
LM293D 8-soic Pin Configuration Guide
Pin configuration for LM293D (8-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 LM293D.
Refer to the datasheet for full pin configuration.
Typical Applications
LM293D is suitable for 6 applications: Battery Voltage Monitoring, Sensor Threshold Detection, Power-Supply Overvoltage Indication, Window Comparator, Industrial Control Interlock, Audio and Communication Level Decision.
Battery Voltage Monitoring
The LM293D fits battery monitoring because its two independent differential comparator channels can evaluate a battery signal against two references or thresholds. One channel can monitor charge state while the other detects overvoltage or an invalid battery condition. The open-drain outputs can pull indicator or digital-input nodes low, while external pull-up resistors establish the active-high logic level. Because the verified excerpts confirm single- or split-supply operation and dual comparators but do not provide exact threshold accuracy, input range, or response time, the battery chemistry, operating voltages, and required limits must be checked against the exact datasheet before deployment.
Recommended
Sensor Threshold Detection
The LM293D is suitable for comparing a sensor-derived voltage with an external reference when a simple digital threshold indication is sufficient. Its differential inputs allow the circuit to monitor the difference between a sensed voltage and a reference rather than requiring an absolute input range. The two channels can support independent rising and falling thresholds, or separate sensor channels. Open-drain outputs make the device convenient for pull-up-based microcontroller inputs, but the source impedance, input bias behavior, common-mode limits, and propagation delay must be confirmed from the selected manufacturer datasheet.
Recommended
Power-Supply Overvoltage Indication
The LM293D can implement an overvoltage or undervoltage indicator by comparing a scaled power-supply voltage with a reference. The open-drain output can directly drive a fault input or pull-up-based status signal, and the dual-channel arrangement permits monitoring two independent rails. The device’s single- or split-supply capability is useful in systems that derive comparator power from different rails, but the exact supply limits and input common-mode range are not included in the verified excerpts. Resistor ratios and fault thresholds must therefore be calculated against the exact LM293D datasheet and the system’s worst-case supply tolerance.
Recommended
Window Comparator
The LM293D’s two independent channels can be configured as upper and lower window comparators for a signal that must remain between two limits. One channel detects when the signal exceeds the upper threshold, while the other detects when it falls below the lower threshold. This arrangement is useful for signal validity, battery operating windows, and analog sensor range checks. Comparator offset and propagation delay affect the actual switching boundaries, so the verified data does not support a numeric threshold-error claim. The design should include hysteresis resistors and verify the selected device’s input and output ratings.
Recommended
Industrial Control Interlock
The LM293D can compare a control signal with a limit reference and provide an interlock output for industrial equipment. Its dual-channel structure allows two independent conditions to be checked without using two separate packages. Open-drain outputs are useful for fail-safe wiring when the pull-up network is designed so that a disconnected, high-impedance, or power-loss condition produces the intended system state. The verified TI material describes an industrial-grade comparator family, while exact environmental ratings, output timing, and fault-state behavior are not supplied. Validate them in the final control circuit and use appropriate protection around exposed industrial nodes.
Recommended
Audio and Communication Level Decision
The LM293D can be used as a simple level or signal-presence decision element in audio and communication interfaces. One channel can compare an incoming signal against a threshold, while the other can provide a complementary or independent decision. The open-drain output allows the decision to be wired to a pull-up-based control or status input. This use does not imply that the LM293D replaces a precision analog signal chain or audio amplifier; it is intended for coarse threshold decisions. Input noise, common-mode range, response time, and output polarity must be verified from the exact datasheet before using it in timing-sensitive or safety-critical signal paths.
Recommended
Recommended Products Summary
Engineering reference data for LM293D — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM393D | LM2903D | LM293D |
|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC - exact pin compatibility requires verification | 8-SOIC - exact pin compatibility requires verification | 8-SOIC - same ordering code, different manufacturer listing |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics |
| Comparator Channels | 2 independent differential comparators | Dual comparator family - exact channel configuration requires datasheet verification | Dual comparator family - exact channel configuration requires datasheet verification | 2 independent low-voltage comparators |
| Special Family Statement | LM293 B-version stated by TI as a drop-in replacement for LM293, LM393, and LM2903 | Related family referenced by TI | Related family referenced by TI | Same MPN listed by multiple manufacturers |
Key Differentiators
- Two independent comparator channels in one 8-SOIC package (vs LM393D)
- Open-collector/open-drain output arrangement (vs LM2903D)
- Family-level interchangeability path (vs LM393D)
- Single- and split-supply architecture (vs LM2903D)
Design Notes
Treat the LM293D open-drain output as a pull-down element, not as a push-pull logic driver. Add a pull-up resistor to the desired logic rail and select its value using the required rise time, output leakage, load capacitance, and available drive current. Check the exact output voltage, sink-current, and power limits in the selected manufacturer datasheet. Never assume that an open-drain output can safely tolerate an arbitrary external voltage.
Route both differential inputs using short, symmetric paths and keep the comparator close to the reference and sensed-signal sources. Place the input bypass capacitor and, when required, a pull-up resistor close to the IC pins. High-impedance sensor nodes are particularly sensitive to leakage, contamination, and nearby switching nodes; use guarding and a stable ground reference where appropriate. The verified data confirms an 8-SOIC package but does not provide a complete pinout, so use the exact datasheet before assigning PCB pads.
Design the comparator supply and pull-up rail from the system’s worst-case voltage range, including startup, transients, and tolerance. A split-supply circuit may be useful when the compared signals are centered around ground, but each supply must remain within the selected LM293D manufacturer’s permitted limits. Do not infer the supply range from the generic LM293 family description; verify absolute maximum and recommended operating conditions before energizing the device.
A comparator decision can chatter when the input crosses the threshold slowly or when noise is present near the reference. Add positive feedback hysteresis or otherwise shape the transition if the downstream load cannot tolerate repeated output transitions. The required hysteresis depends on the actual offset voltage, input bias behavior, resistor noise, and input signal dynamics, all of which are marked as data-needed where the verified excerpts are incomplete.
Compliance Information
The supplied verified web data does not include RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations for LM293D. Compliance must be confirmed using the exact manufacturer’s product documentation.
