Texas Instruments LM293D

Overview

LM293D from Texas Instruments is a dual voltage comparator IC designed for single-supply operation across 2 V to 30 V, featuring ±9 mV max input offset voltage, 1.3 µs typical response time, 4 mA output sink capability, and rail-to-rail input common-mode range down to ground-used in motor drive feedback, power supply monitoring, and appliance control circuits.

For engineers reviewing the LM293D datasheet, LM293D pinout, LM293D application, or LM293D equivalent, key selection criteria include input offset voltage tolerance, supply voltage range compatibility, open-collector output drive strength, temperature grade (–25°C to +85°C), and SOIC-8 package footprint constraints in industrial and consumer power management designs.

Technical Context

The LM293D implements two independent high-gain comparators with open-collector outputs, enabling wired-OR logic and flexible pull-up configuration. Its input stage supports common-mode voltages from ground to V_CC – 2 V, allowing direct sensing of low-side current shunts or battery terminals without level shifting.

Propagation delay is optimized for TTL-compatible transitions, with 1.3 µs typical response under 5 V supply and 15 pF load. Quiescent current remains stable across supply voltage (0.45–2.5 mA), supporting wide-input-range applications like server PSUs and cordless tool battery management.

Key Specifications

Pinout & Package

LM293D is packaged in an 8-pin SOIC (Small Outline Integrated Circuit) with 4.90 mm × 3.91 mm body size and standard 1.27 mm pitch. The package is surface-mount, RoHS-compliant, and thermally rated for 148.5°C/W junction-to-ambient resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual comparator applications.

Compared with LM293D, LM393DR offers lower cost but reduced temperature resilience, while LM2903DT delivers enhanced thermal robustness at slightly higher unit price-both retain identical pinout and core comparator performance for drop-in evaluation.

Availability

LM293D is available at Aetrix Electronics and suitable for motor drive feedback, server PSU monitoring, and appliance control applications requiring stable component supply, long-lifecycle support, and consistent SOIC-8 packaging.

Supply support for LM293D includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of experience in precision signal chain and power management ICs.

The LM293D belongs to TI's legacy dual comparator family, engineered for cost-sensitive, high-reliability industrial and consumer applications where simplicity, wide supply range, and proven robustness are prioritized over ultra-low offset or speed.

FAQ

What is the maximum supply voltage rating for LM293D?

The LM293D has an absolute maximum supply voltage of 36 V, but its recommended operating range is 2 V to 30 V per the datasheet. Operating above 30 V may degrade long-term reliability or exceed guaranteed specifications such as input offset drift or propagation delay stability. Always observe the 30 V limit in continuous operation for LM293D to ensure compliance with published electrical characteristics.

Does LM293D support rail-to-rail input operation?

LM293D supports common-mode input voltages from ground (0 V) up to V_CC – 2 V, which qualifies as rail-to-rail on the lower end but not fully to V_CC. This allows direct connection to ground-referenced signals like current-sense amplifier outputs, but inputs exceeding V_CC – 2 V risk incorrect output behavior. The LM293D datasheet explicitly confirms this range in Section 5.2 Recommended Operating Conditions.

Can LM293D drive a 5 V logic input directly?

Yes, LM293D can interface with 5 V logic inputs using an external pull-up resistor to 5 V on its open-collector outputs. When inactive, the output floats high; when active, it sinks current to ground. Ensure the pull-up value (e.g., 4.7 kΩ) limits sink current to ≤6 mA. No level-shifter is needed, making LM293D compatible with standard 5 V TTL/CMOS loads in mixed-voltage systems.

What is the input offset voltage specification for LM293D?

The LM293D has a maximum input offset voltage of ±9 mV over its full operating temperature range (–25°C to +85°C), with typical values around ±2 mV at 25°C. This parameter is critical for precision threshold detection-e.g., in battery voltage monitors-where offset contributes directly to trip-point error. The value is confirmed in Section 5.8 of the TI datasheet SLCS005AH for non-A/non-B versions.

Is LM293D pin-compatible with LM393 or LM2903?

Yes, LM293D is pin-compatible with LM393 (commercial grade) and LM2903 (industrial grade) in SOIC-8 packages, sharing identical pin functions and electrical behavior. All three use the same 8-pin layout: 1OUT, 1IN−, 1IN+, GND, 2IN+, 2IN−, 2OUT, VCC. However, temperature ratings differ-LM293D is –25°C to +85°C, LM393 is 0°C to +70°C, and LM2903 is –40°C to +125°C-so thermal validation is required for cross-substitution.