STMicroelectronics L293E

Overview

L293E from STMicroelectronics is a quad push-pull driver IC designed for bidirectional DC motor and bipolar stepper motor control, delivering 1A continuous output current per channel (2A peak), with separate logic supply (4.5–36V), inhibit control, and external current-sense resistor connections for switch-mode operation.

For engineers reviewing the L293E datasheet, L293E pinout, L293E application, or L293E equivalent, key selection criteria include per-channel 1A drive capability, thermal resistance (14°C/W junction-to-case), V_CE(sat) ≤1.8V at ±1A, sensing voltage of 2V on pins 4/7/14/17, and DIP-20 package with heatsinking center pins.

Technical Context

The L293E integrates four independent push-pull output stages, each with TTL-compatible inputs and dedicated inhibit control per bridge pair. Its architecture supports H-bridge configurations without external flyback diodes due to internal clamp protection.

Unlike the L293B (DIP-16), the L293E uses a 20-pin PowerDIP package with two additional pins (4 and 7) for external current-sensing resistors-enabling closed-loop current limiting in PWM-driven motor applications.

Key Specifications

Pinout & Package

Package: 20-pin Plastic Dual In-line Package (PowerDIP-20), with pins 10, 11, 12, and 13 internally connected to ground and externally exposed for PCB copper heatsinking (R_{th j-amb} reduced to ~30°C/W with proper layout).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad H-bridge driver applications.

Compared with L293D and TB6612FNG, the L293E uniquely balances through-hole manufacturability, 1A drive capability, and external current-sense flexibility-making it optimal for industrial repair, educational labs, and legacy board upgrades requiring thermal robustness and analog current feedback.

Availability

L293E is available at Aetrix Electronics and suitable for DC motor control, bipolar stepper drive, industrial actuator interface, and lab equipment motion control requiring stable component supply across extended product lifecycles.

Supply support for L293E 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, motor control, and automotive-grade analog/mixed-signal ICs.

The L293E belongs to ST's legacy motor driver portfolio, engineered specifically for cost-sensitive industrial and educational applications requiring rugged through-hole packaging, thermal resilience, and flexible current-sensing integration.

FAQ

What is the maximum safe operating voltage for the L293E motor supply (V_S)?

The absolute maximum V_S rating is 36V, but sustained operation above 24V increases conduction losses and thermal stress. For reliable 1A continuous output, ST recommends limiting V_S to ≤24V with adequate PCB heatsinking on pins 10–13, especially at ambient temperatures >50°C.

Can the L293E drive a unipolar stepper motor?

No-the L293E is designed exclusively for bipolar stepper motors and DC motors. Unipolar steppers require center-tapped windings and single-ended switching, which the L293E's H-bridge topology does not support. Using it with unipolar motors risks incorrect phasing and insufficient torque generation.

Why do pins 4, 7, 14, and 17 exist on the L293E but not on the L293B?

These pins provide external access to internal current-sense nodes, enabling closed-loop current regulation in switch-mode motor control. The L293B lacks these connections-its sense nodes are internally tied to ground-making the L293E the only variant supporting adjustable current limiting via external shunt resistors.

Is a heatsink required for continuous 1A operation per channel?

Yes-without PCB copper heatsinking on pins 10/11/12/13, junction temperature exceeds safe limits within seconds at 1A. ST specifies R_{th j-amb} = 80°C/W without heatsinking; achieving ≤1A continuous requires reducing this to ≤30°C/W via ≥250mm² copper area or external heatsink per ST Application Note AN2401.