LM393DT Dual Low-Power Voltage Comparator: Specs, Design Guide, and Drop-In Alternatives

Quick Answers: What Is the LM393DT and Is It Available Today?

The LM393DT is a dual low-power voltage comparator from STMicroelectronics. It operates from a single 2 V to 36 V supply or dual ±1 V to ±18 V supplies, draws only 0.4 mA typical per comparator, and has an open-collector output that can sink up to 16 mA. In the SOIC-8 package, the LM393DT offers a typical response time of 1.3 µs, a typical input offset voltage of 2 mV, and a typical input bias current of 25 nA. As of 2026-08-21, the LM393DT is in active lifecycle status and XAIPART stock is 99,999 units; the verified 1,000-piece price is $0.0461 per unit.

This article compiles verified specs, a practical design guide, drop-in alternatives from the XAIPART database, and procurement insight for engineers using the LM393DT in battery monitors, level shifters, window comparators, oscillators, and ADC front ends.

Verified pricing from XAIPART as of 2026-08-21: $0.0791 at qty 1, $0.0571 at qty 10, $0.0505 at qty 100, $0.0483 at qty 500, and $0.0461 at qty 1,000. You can check real-time availability on the LM393DT product page.

Technical Guide: How to Select, Design In, and Use the LM393DT

When you need two independent voltage comparators in a single SOIC-8 package, the LM393DT is a practical baseline. The verified 2 V to 36 V single-supply range lets you run the part directly from a 3.3 V rail, a 5 V rail, or an industrial 24 V rail. If you need dual supplies, the verified range is ±1 V to ±18 V.

The LM393DT uses a bipolar differential input stage and an open-collector output stage. The open-collector output cannot source current; it can only sink current up to 16 mA. Therefore, every LM393DT output needs an external pull-up resistor. The resistor value depends on the target logic-high voltage and the acceptable rise time. A common starting point is 10 kΩ. At 5 V, this limits sink current to 0.5 mA, well below the 16 mA maximum.

The input common-mode voltage range is verified as 0 V to VCC - 1.5 V. For a 5 V supply, both inputs must remain between 0 V and 3.5 V. If the monitored signal is outside this range, scale it with a resistor divider or add a protection network. The 2 mV typical input offset voltage and 25 nA typical input bias current let you calculate threshold accuracy for precision circuits.

The LM393DT has a typical response time of 1.3 µs with a 5 V overdrive. This is suitable for battery monitoring, zero-crossing detection, relay control, and low-frequency oscillator circuits. It is not the right choice for gigabit-speed or high-frequency comparator applications.

The verified operating temperature range is -40°C to +105°C. The SOIC-8 package, RoHS compliance, and MSL Level 1 rating simplify assembly and support automated surface-mount production.

Verified pinout from the STMicroelectronics datasheet:

Design checklist:

• Power the LM393DT from a supply between 2 V and 36 V single-ended, or between ±1 V and ±18 V dual.
• Add a pull-up resistor to each open-collector output and verify sink current stays below 16 mA.
• Keep both inputs within the 0 V to VCC - 1.5 V common-mode range.
• Account for 2 mV typical input offset voltage and 25 nA typical input bias current.
• Budget for 1.3 µs typical propagation delay when calculating loop response.
• For wired-OR outputs, connect both open-collector outputs together with a single pull-up resistor.

For a two-channel window comparator, use comparator 1 for the upper threshold and comparator 2 for the lower threshold. Tie the open-collector outputs together with a single pull-up resistor. When the input is outside the window, the wired-OR output pulls low.

For a relaxation oscillator, connect one comparator with a feedback resistor and timing capacitor. The open-collector output charges and discharges the capacitor through the feedback network. The 1.3 µs response time limits practical frequencies to a few hundred kilohertz, which is adequate for many timing and tone-generation circuits.

For level shifting, connect the high-voltage-side pull-up to the target logic rail. The LM393DT's input bias current is only 25 nA typical, so it loads the source minimally. The open-collector output switches between 0 V and the pull-up rail, translating a 3.3 V input into a 5 V or 12 V logic signal. Response time of 1.3 µs supports low-speed serial interfaces such as UART and I2C.

For battery voltage monitoring, connect the battery through a resistor divider to keep the sense voltage inside the common-mode range. Use a stable reference at the other input. The low 0.4 mA supply current helps preserve battery life, and the 16 mA sink capability can drive an LED or microcontroller interrupt.

Alternatives & Comparison: Which Drop-In Replacements Are Available?

Engineers often need a second source. The verified XAIPART database lists three SOIC-8 drop-in alternatives for the LM393DT. Each shares the same package and pinout, so a PCB designed for the LM393DT can accept these parts if the electrical specs match.

Use the table as a screen, then verify each candidate's exact offset voltage and timing from the corresponding manufacturer datasheet before changing the BOM. Preferred internal links:

• LM393DT product page
• Amplifier ICs category
• Voltage comparator guides

Industry Insight: Market Position, Lifecycle, and Supply Situation

The verified XAIPART database shows the LM393DT with active lifecycle status. Active means STMicroelectronics lists the part as a current, supported product, so you can design it into new projects.

Stock data indicates 99,999 units available. This volume supports prototyping and small-to-medium production runs without long lead times. For high-volume blanket orders, confirm inventory directly on the product page.

The verified pricing schedule as of 2026-08-21 is $0.0791 at qty 1, $0.0571 at qty 10, $0.0505 at qty 100, $0.0483 at qty 500, and $0.0461 at qty 1,000. The unit cost decreases with volume, a typical procurement curve for commodity dual comparators.

The LM393DT competes in the general-purpose dual comparator segment. Similar SOIC-8 parts come from Texas Instruments and onsemi. Specific market share and regional demand data are not in the verified product database.

Trends & Outlook: What Should Buyers Watch for the LM393DT?

The 2 V minimum supply voltage keeps the LM393DT compatible with modern 3.3 V microcontroller systems, while the 36 V maximum supply rating supports 24 V industrial rails. That wide envelope makes the part useful across low-voltage portable and industrial control designs.

Low power remains a key buying criterion. At 0.4 mA per comparator typical, the LM393DT is appropriate for always-on battery monitors and threshold detectors. The open-collector output and 16 mA sink capability allow direct interface to LEDs, logic inputs, and small relays through a suitable pull-up resistor.

Because the verified alternatives LM393DR, LM393M, and LM393ADT share the same SOIC-8 package and pinout, buyers can create a multi-source BOM. Keeping a second source approved reduces supply-chain risk, especially when a commodity part experiences allocation.

Finally, check stock and pricing at order time. As of 2026-08-21, the LM393DT is in stock at XAIPART with 99,999 units; the 1,000-piece price is $0.0461. Visit the LM393DT product page for updated inventory.