STMICROELECTRONICS MC34063A DC-DC Converter Controller IC, SMD, SOIC-8

The STMICROELECTRONICS MC34063ABD-TR is a versatile and highly efficient monolithic control circuit designed for DC-DC voltage conversion. This integrated circuit provides all the essential functions required for step-down (buck), step-up (boost), and voltage-inverting applications, making it a fundamental component in a wide range of power supply designs. Its architecture includes an internal temperature-compensated voltage reference, a comparator, a duty-cycle-controlled oscillator with active current limiting, a driver, and a high-current output switch.

A key advantage is its adjustable output voltage, which can be set precisely via two external resistors, benefiting from a 2% reference accuracy. The device operates from a wide input voltage range of 3V to 40V and can handle output switch currents exceeding 1.5A, all while maintaining a low typical quiescent current of just 2.5mA. This combination of performance and efficiency makes it suitable for both battery-powered and line-operated equipment.

Technical Performance

The controller supports a switching frequency up to 100kHz, with a typical frequency of 33kHz, contributing to compact inductor and capacitor sizing. It features active current limiting for protection and reliable operation across an extended ambient temperature range from -40°C to +85°C. Housed in a space-saving SOIC-8 (SO-8) surface-mount package, it is designed for automated assembly on modern PCBs.

Specifications Overview

• Topology: Supports Buck, Boost, and Inverting configurations.
• Input Voltage: 3V to 40V.
• Max Output Current: 1.5A.
• Output Voltage Range: Adjustable from 1.25V to 38V.
• Switching Frequency: Up to 100kHz (33kHz typical).
• Typical Efficiency: 89%.
• Package: 8-pin SOIC (Surface-Mount).

Engineers and designers value the MC34063A for its ability to deliver robust DC-DC power