In portable electronics, IoT nodes, and embedded systems, the performance of a voltage regulator affects not only efficiency but also the stability and reliability of the entire system. While switching regulators dominate high-efficiency applications, low dropout regulators (LDOs) remain irreplaceable in scenarios that demand low noise, fast transient response, and simple circuitry.
The LDL112PV33R, from STMicroelectronics, is a high-performance LDO regulator with a fixed 3.3 V output and up to 1.2 A output current. It features ultra-low quiescent current, low dropout voltage, and high power supply rejection ratio (PSRR). These traits make it ideal for portable devices that require stable power and low electromagnetic interference (EMI). Designed for long battery life, stable supply, and compact form factor, it is well suited to the growing demand for highly integrated, low-power electronics.
Key Technical Features
Output Performance and Electrical Specifications
- Fixed 3.3 V output with ±2% accuracy at 25 °C, ensuring a stable supply to the load.
- Up to 1.2 A output current, supporting medium-power MCUs, wireless modules, and multiple sensors.
- Typical dropout of only 300 mV at 1 A load. This allows the device to maintain regulated output even when battery voltage is near its cutoff level.
Power Consumption
- Typical quiescent current of 35 µA at no load. Less than 1 µA in shutdown mode, reducing standby power draw.
- Wide input voltage range of 1.6 V to 5.5 V. Compatible with single-cell Li-ion batteries, USB, or DC-DC converter outputs.
Stability and Noise Rejection
- PSRR of up to 57 dB at 1 kHz. Effectively suppresses input ripple and high-frequency noise.
- Internal compensation optimized for low ESR ceramic capacitors. Simplifies component selection and improves system stability.
- Low output noise, suitable for analog front ends and RF signal chains that demand a clean supply.
Protection Features
- Current limit to protect against short circuits or overloads.
- Thermal shutdown to prevent overheating. Automatically restarts when temperature returns to safe levels.
- Reverse current protection to prevent backflow when output voltage exceeds input voltage.
Package and Thermal Design
The LDL112PV33R comes in a compact DFN-6 (3×3 mm) package with an exposed thermal pad. This pad can be soldered to a large PCB ground plane for better heat dissipation.
Advantages of this package include:
- Saving PCB space for flexible layout.
- Low profile for ultra-thin portable products.
- Direct thermal conduction to internal or backside copper layers, keeping temperatures stable under high load.
For continuous operation above 1 A, it is recommended to provide at least 2 cm² of copper area connected to the thermal pad, with multiple vias to spread heat effectively.
Advantages in Portable Applications
Extended Battery Life
Low dropout combined with ultra-low quiescent current allows operation closer to the battery’s discharge limit, reducing wasted capacity.
Stable Power for Sensitive Loads
High PSRR and low noise output make it ideal for audio processors, RF modules, and MEMS sensors, minimizing supply-induced signal degradation.
Simplified Design and Higher Reliability
No need for bulky magnetic components. Requires only a few capacitors, reducing BOM cost and design complexity. Comprehensive protection features ensure reliable operation even in harsh conditions.
Typical Applications
- Smartwatches and fitness trackers
- Medical monitoring devices such as ECG recorders and glucose meters
- Wireless IoT nodes (LoRa, ZigBee, BLE)
- Portable test instruments and sensor gateways
- Cameras and image processing modules
Design and Integration Guidelines
- Input and Output Capacitors: Use at least 1 µF ceramic on input and at least 1 µF low ESR ceramic on output. This ensures stable operation and fast transient response.
- PCB Layout: Place the input capacitor close to the device pins to minimize loop area and EMI. Add an LC filter at the input for RF-sensitive designs.
- Thermal Management: Ensure the exposed pad has proper thermal contact. Use backside copper or heat spreaders when running at high currents.
- Dynamic Power Control: Use the enable (EN) pin to shut down the regulator during idle periods, minimizing total system power draw.
The LDL112PV33R combines low dropout voltage, low power consumption, high PSRR, compact packaging, and robust protection features. It is an excellent choice for portable and low-power system designs. It not only extends battery life but also provides high-quality power in noise-sensitive applications.
As the electronics industry moves toward higher integration and lower power budgets, high-performance LDOs like the LDL112PV33R will remain essential for powering smart devices, IoT endpoints, and precision measurement equipment.
As a leading global distributor of electronic components, WIN SOURCE offers the LDL112PV33R and a wide selection of power management devices from multiple brands. We support engineers and manufacturers with reliable sourcing, ensuring faster and more stable product development in today’s rapidly evolving market.
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