LP5907-33
High PSRR LDO with 3.3V output and ultra-low noise for sensitive analog and RF circuit applications
Product Overview
Description
The LP5907-33 is a high PSRR (Power Supply Rejection Ratio) LDO regulator designed for noise-sensitive applications such as precision analog circuits, RF systems, and high-resolution ADCs. With 80dB PSRR at 1kHz, it effectively rejects power supply noise.
The device delivers a fixed 3.3V output with up to 250mA output current. It features ultra-low output noise of only 10μVRMS, making it ideal for powering sensitive analog circuits where noise directly impacts performance. The fast transient response handles load steps with minimal output voltage variation.
The LP5907-33 includes enable pin for power sequencing, current limit protection, and thermal shutdown. Available in a compact SOT-23-5 package, it is perfect for portable audio devices, RF modules, and precision measurement systems.
Product Series
LP
Primary Application
RF modules and transceivers
Key Features
- High 80dB PSRR at 1kHz
- Ultra-low 10μVRMS output noise
- 250mA maximum output current
- Low 200mV dropout voltage
- Enable pin for power sequencing
- Current limit protection
- Thermal shutdown protection
- Compact SOT-23-5 package
Specifications
| Output Voltage | 3.3V (fixed) |
|---|---|
| Output Current | 250mA max |
| Quiescent Current | 30μA (typical) |
| Dropout Voltage | 200mV @ 250mA |
| PSRR | 80dB @ 1kHz |
| Output Noise | 10μVRMS (10Hz-100kHz) |
| Input Voltage Range | 2.5V - 5.5V |
| Load Regulation | ±0.5% |
| Operating Temperature | -40°C to +85°C |
| Package | SOT-23-5 |
Applications
RF modules and transceivers
Electronic system design
Precision analog circuits
Electronic system design
Audio codecs and DACs
Electronic system design
High-resolution ADCs
Electronic system design
Camera modules
Electronic system design
FAE Expert Insights
"The LP5907-33 is my recommendation for any noise-sensitive analog application. The 80dB PSRR is genuinely impressive - I've used it to power 16-bit ADCs in precision measurement systems with excellent results. The 10μVRMS output noise is among the lowest in this class of LDOs. In a recent RF module design, switching from a generic LDO to the LP5907 reduced spurious emissions by 15dB. The enable pin is useful for power sequencing in complex systems. One thing to note: the 30μA quiescent current is higher than ultra-low power LDOs, so it's not the best choice for always-on battery applications. But for noise-sensitive circuits, the trade-off is absolutely worth it. I recommend using a 2.2μF output capacitor for best noise performance. The thermal performance is good for the package size, but watch the power dissipation at high input voltages. Overall, an excellent high-performance LDO at a reasonable price."
High PSRR LDO with ultra-low noise for sensitive analog and RF applications
— Li Ming, BeiLuo
Frequently Asked Questions
What is the PSRR of LP5907-33?
The LP5907-33 features a high PSRR of 80dB at 1kHz, which effectively rejects power supply noise and ripple. This high PSRR makes it ideal for powering noise-sensitive analog circuits, RF modules, and precision ADCs where power supply quality directly impacts performance.
80dB PSRR excellent for noise-sensitive applications; verify PSRR at your specific noise frequencies.
What is the output noise of LP5907-33?
The LP5907-33 has ultra-low output noise of only 10μVRMS over the 10Hz to 100kHz bandwidth. This low noise level is critical for sensitive analog circuits where voltage noise can directly impact measurement accuracy or signal quality.
10μVRMS noise suitable for precision analog; use for ADCs, DACs, and RF circuits.
What is the quiescent current of LP5907-33?
The LP5907-33 has a quiescent current of 30μA typical. While this is higher than ultra-low power LDOs, it is reasonable for a high PSRR device. For always-on battery applications, consider the LP3990 series with 1μA quiescent current instead.
30μA IQ acceptable for powered analog circuits; use LP3990 for always-on battery applications.
Does LP5907-33 have an enable pin?
Yes, the LP5907-33 includes an active-high enable pin that allows power sequencing and power-down control. The enable pin has internal pull-down to ensure the regulator is off when the enable pin is floating. This feature is useful for multi-rail power systems.
Enable pin useful for power sequencing; connect to logic high to enable, logic low or leave floating to disable.
What applications benefit most from LP5907-33?
The LP5907-33 is ideal for noise-sensitive applications including RF modules and transceivers, precision analog circuits, audio codecs and DACs, high-resolution ADCs, and camera modules. The high PSRR and low noise ensure optimal performance in these applications.
Use for noise-sensitive analog and RF circuits; choose LP3990 for general digital circuits.
What capacitors are recommended for LP5907-33?
For the LP5907-33, use a 1μF ceramic input capacitor and a 2.2μF ceramic output capacitor for best noise performance. Place capacitors close to the IC pins. X5R or X7R dielectric capacitors are recommended for stable characteristics across temperature.
Use 2.2μF output capacitor for best noise performance; place close to IC pins.
What is the dropout voltage of LP5907-33?
The LP5907-33 has a dropout voltage of 200mV at the maximum 250mA output current. This low dropout allows the regulator to maintain regulation even when the input voltage is close to the output voltage, which is important for battery-powered applications.
200mV dropout suitable for most applications; verify input voltage margin for your battery configuration.