WL2831D
300mA low-dropout linear regulator with ultra-low noise (6uVrms) and high PSRR (80dB at 1kHz) for RF and analog power...
Product Overview
Description
The WL2831D is a high-performance 300mA LDO regulator designed for noise-sensitive applications such as RF circuits and precision analog systems.
With ultra-low output noise of only 6uVrms and high power supply rejection ratio of 80dB at 1kHz, it provides clean power for sensitive circuits.
The device features a wide input voltage range of 1.7V to 5.5V and is available in fixed and adjustable output voltage versions.
Product Series
WL
Primary Application
RF power supplies
Key Features
- Ultra-low output noise: 6uVrms typical
- High PSRR: 80dB at 1kHz, 50dB at 100kHz
- Low dropout voltage: 120mV at 300mA
- Wide input voltage range: 1.7V to 5.5V
- Fast transient response
- Current limit and thermal protection
Specifications
| Input Voltage | 1.7V to 5.5V |
|---|---|
| Output Voltage | 1.2V to 3.3V (fixed/adj) |
| Output Current | 300mA |
| Dropout Voltage | 120mV @ 300mA |
| Output Noise | 6uVrms (10Hz-100kHz) |
| PSRR | 80dB @ 1kHz |
| Package | SOT-23-5, DFN-6 |
Applications
RF power supplies
Electronic system design
Camera sensor power
Sensor signal conditioning
Precision analog circuits
Electronic system design
Audio circuits
Electronic system design
Communication modules
Communication and interface
FAE Expert Insights
"The WL2831D is my go-to recommendation for powering noise-sensitive circuits. The 6uVrms noise figure is among the best in its class. I've used this LDO in camera module designs where clean analog power is critical for image quality. The high PSRR effectively filters switching noise from upstream DC-DC converters. The dropout voltage is reasonable for a low-noise design. For RF applications, the noise performance ensures minimal impact on receiver sensitivity. The SOT-23-5 package is convenient for compact designs. Overall, this LDO offers excellent performance at a competitive price point."
Ultra-low noise performance for sensitive analog circuits
— James Wilson, BeiLuo
Frequently Asked Questions
What is the dropout voltage of WL2831D?
The WL2831D features a low dropout voltage of typically 120mV at 300mA load current when Vout is 3.3V. Dropout voltage scales with output current - at 150mA it is approximately 60mV, and at 50mA it is about 20mV. The dropout voltage also varies slightly with output voltage setting. This low dropout allows the LDO to maintain regulation even when input voltage is close to output voltage, maximizing battery life in portable applications. The dropout characteristic is fully specified over temperature in the datasheet.
Ensure your minimum input voltage is at least dropout voltage plus output voltage. Contact us for dropout calculations under your specific conditions.
How does the PSRR of WL2831D compare to other LDOs?
The WL2831D offers excellent PSRR (Power Supply Rejection Ratio) performance: 80dB at 1kHz, 70dB at 10kHz, 60dB at 100kHz, and 50dB at 1MHz. This high PSRR effectively attenuates ripple and noise from the upstream power supply, making it ideal for sensitive analog and RF circuits. Compared to general-purpose LDOs which typically offer 40-60dB PSRR at 1kHz, the WL2831D provides significantly better noise rejection. The PSRR performance is maintained across the operating voltage and current range.
For applications sensitive to power supply noise, WL2831D's high PSRR provides superior performance. Contact us for PSRR measurement data.
What packages are available for WL2831D?
The WL2831D is available in two package options: SOT-23-5 (2.9mm x 1.6mm) for general applications; and DFN-6 (2mm x 2mm) for space-constrained designs. Both packages have identical electrical performance. The SOT-23-5 is easier to handle and inspect during manufacturing. The DFN-6 offers smaller footprint and better thermal performance due to exposed pad. Package selection depends on space constraints and manufacturing capabilities. Both packages are RoHS compliant and lead-free.
Choose SOT-23-5 for ease of manufacturing or DFN-6 for compact designs. Contact us for package thermal characteristics.
What is the thermal performance of WL2831D?
The WL2831D thermal performance depends on package type and PCB layout. The SOT-23-5 package has thermal resistance (Theta-JA) of approximately 200°C/W on standard PCB. The DFN-6 with exposed pad achieves better thermal performance of about 80°C/W with proper copper area. Maximum power dissipation is limited by junction temperature (125°C maximum). For example, at 3.6V input and 1.8V output at 300mA, power dissipation is 540mW. With SOT-23-5, temperature rise is approximately 108°C, requiring careful thermal management. The DFN-6 would have about 43°C rise under same conditions.
For high power dissipation applications, use DFN-6 package with adequate copper area. Contact us for thermal design recommendations.
Does WL2831D support adjustable output voltage?
Yes, the WL2831D is available in both fixed output voltage versions (1.2V, 1.5V, 1.8V, 2.5V, 2.8V, 3.0V, 3.3V) and an adjustable version. The adjustable version uses external resistor divider to set output voltage from 0.8V to 4.5V. The feedback voltage is 0.8V typical. Fixed voltage versions offer better accuracy (±1%) and require fewer external components. Adjustable version provides flexibility for non-standard voltages. Both versions have identical electrical characteristics and protection features.
Use fixed voltage for standard rails to minimize BOM. Use adjustable version for custom voltages. Contact us for resistor divider calculations.