L293DD

Overview

The L293DD is a monolithic integrated high voltage, high current four-channel driver from the L293D series by STMicroelectronics. Designed for surface mount assembly in a 20-lead SOIC package with eight center pins connected for heatsinking, it accepts standard DTL or TTL logic levels to drive inductive loads such as relays, solenoids, DC motors, and stepping motors. The device features a separate supply input for logic operation at lower voltages and includes internal clamp diodes. It supports switching applications up to 5 kHz, operates within a temperature range of -40°C to +150°C, and handles a maximum power supply voltage of 36V.

Feature Summary

• Push-pull four-channel architecture with enable inputs for simplified bridge configuration
• Integrated internal clamp diodes for inductive load protection
• Overtemperature protection mechanism for thermal safety
• High noise immunity with logical '0' input voltage capability up to 1.5 V

Applications

• Driving brushed DC motors
• Controlling stepping motors
• Actuating relays and solenoids
• Switching power transistors

Procurement Notes

Verify component authenticity through authorized STMicroelectronics distributors or verified suppliers. Confirm the specific suffix matches the required packaging format, as tape-and-reel variants exist. Ensure compliance with RoHS directives and check moisture sensitivity levels prior to soldering. Validate that the SOIC-20 package dimensions align with PCB footprint requirements. Review datasheet specifications for thermal management needs given the exposed pad design.

Selection Notes

Select the L293DD when standard DTL or TTL logic compatibility is required for driving inductive loads. Choose this part for applications needing dual full-bridge control with individual channel enablement. Consider its 600 mA continuous output per channel and 1.2 A peak capability for moderate current demands. Opt for this surface-mount variant over through-hole versions when space efficiency and automated assembly are priorities. Evaluate thermal dissipation requirements due to the lack of active cooling integration.

Part Context

The L293DD belongs to the L293D family of push-pull four-channel drivers. While the standard L293D utilizes a 16-lead plastic package with four center pins for heatsinking, the L293DD adapts this functionality to a 20-lead surface mount SOIC package with eight center pins. This variation maintains the core electrical characteristics and logic interface while offering a different mechanical form factor suitable for modern PCB layouts.

Replacement Considerations

Direct pin-to-pin replacements within the same package may include other manufacturers' equivalents of the L293D series. Verify electrical parameters such as output current and voltage ratings before substitution. Check if alternative parts offer enhanced features like PWM current control or diagnostic outputs if system complexity allows.