Voltage Regulator, LDO 3.3V, SMD, SOT-223

The STMICROELECTRONICS LD1117S33CTR is a high-performance, low-dropout (LDO) voltage regulator providing a fixed 3.3V output. Capable of delivering up to 800mA of continuous output current, it is engineered for stability and efficiency in compact surface-mount designs.

It features an NPN pass transistor architecture, which ensures high efficiency by directing the majority of the quiescent current into the load, rather than being wasted as ground current. This design, coupled with on-chip trimming, achieves a very tight output voltage tolerance of within ±1% at 25°C.

Key Features & Specifications

• High Output Current: Provides up to 800mA output current, with a typical peak of 950mA.
• Low Dropout Voltage: Features a typical dropout voltage of just 1V, making it suitable for applications where the input voltage is only slightly higher than the required output.
• Excellent Regulation: Offers superior line and load regulation (typically 0.1%), ensuring a stable 3.3V supply even with fluctuations in input voltage or load current.
• Thermal & Current Protection: Includes internal current limiting and thermal shutdown to protect the device and the circuit under fault conditions.
• Low Noise & High PSRR: Delivers a low output noise voltage (typically 100µV) and a high supply voltage rejection ratio (typically 75dB), ideal for noise-sensitive analogue and digital circuitry.
• Minimal External Components: Requires only a common 10μF capacitor at the output for stability, simplifying board design and saving space.

Housed in a space-saving SOT-223 surface-mount package, this regulator is optimised for thermal performance. Its robust design supports an operating temperature range from -40°C to +125°C, making it suitable for a wide array of commercial and industrial applications where a reliable, regulated 3.3V rail is essential.