STMicroelectronics LD1117DT33TR Linear Voltage Regulator IC 3.3V 800mA DPAK Package

STMicroelectronics LD1117DT33TR: Precision Linear Regulation for Demanding Applications

In modern electronic systems, stable voltage regulation is critical for ensuring reliability and performance. The STMicroelectronics LD1117DT33TR stands out as a high-precision linear voltage regulator designed to deliver a fixed 3.3V output with up to 800mA of current, making it ideal for powering sensitive components in industrial, automotive, and embedded systems. This DPAK-packaged IC combines robust thermal management, low dropout voltage, and comprehensive protection features to meet the demands of engineers requiring dependable power solutions.

Technical Excellence in Voltage Regulation

At its core, the LD1117DT33TR operates as a positive-output fixed regulator with a maximum input voltage of 15V. Its key differentiator lies in its ability to maintain regulation even under varying load conditions, thanks to a dropout voltage of just 1.2V at full 800mA output. This characteristic ensures efficient operation in battery-powered systems where maintaining output stability during voltage sag is critical.

Built for Reliability in Harsh Environments

Engineered for industrial applications, this regulator operates across an extended temperature range of 0°C to 125°C while maintaining output accuracy. The DPAK surface-mount package provides excellent thermal dissipation through its tab-connected lead frame, allowing direct PCB mounting for both mechanical stability and thermal efficiency. Integrated protection features safeguard against overcurrent and thermal overload conditions – critical for preventing damage in unexpected fault scenarios.

Designers will appreciate the device's compatibility with standard surface-mount assembly processes, eliminating the need for special handling during production. The TO-252-3 package format offers a compact footprint while maintaining the thermal advantages of larger power packages. For applications requiring noise-sensitive power supplies, the 75dB power supply rejection ratio (PSRR) at 120Hz ensures minimal output voltage fluctuations from input ripple.

Design Considerations and Applications

The LD1117DT33TR's 10mA maximum quiescent current makes it suitable for systems where standby power consumption matters. When designing with this regulator, engineers should consider:

• Input capacitance requirements for stability
• Thermal vias in PCB layout for optimal heat dissipation
• Output capacitor ESR specifications
• Load transient response characteristics

Common applications include powering microcontrollers, FPGAs, and precision sensors in test equipment, industrial automation systems, and telecommunications hardware. Its fixed output voltage design simplifies implementation while reducing component count compared to adjustable versions.

Performance Advantages Over Alternatives

Compared to switching regulators, the LD1117DT33TR offers superior noise performance and simpler implementation at the expense of lower efficiency in high-step-down scenarios. When contrasted with older linear regulators, its 1.2V dropout voltage enables operation at lower input margins, extending usable battery life in portable devices. The thermal shutdown feature with hysteresis provides automatic recovery from overheating events without requiring external monitoring circuitry.

For designers transitioning from through-hole components, the DPAK package offers equivalent thermal performance in a surface-mount format that supports automated assembly. The device's parametric stability over temperature ensures consistent performance in demanding environments where thermal cycling might affect less robust solutions.

Conclusion: A Trusted Power Solution

The LD1117DT33TR represents STMicroelectronics' commitment to delivering high-performance analog components for modern electronic design. With its combination of electrical precision, thermal robustness, and ease of integration, this regulator addresses the critical power needs of contemporary systems while maintaining backward compatibility with established design practices. Stocked in 20,000+ piece quantities with competitive pricing at $0.09 per unit in volume production, it offers both economic and technical advantages for projects requiring proven voltage regulation technology.

Tags: Linear Regulator IC, 3.3V Power Supply, Industrial Voltage Control, High Current Regulator, Embedded System Components