3.3V, 50mA Low-Dropout Regulator with High PSRR in SOT-23-5 Package

In the realm of modern electronics, the demand for stable, clean, and efficient power management is paramount. The 3.3V, 50mA low-dropout (LDO) regulator stands out as a critical component, especially when designed within the compact SOT-23-5 package and engineered for high Power Supply Rejection Ratio (PSRR). This combination of features makes it an ideal solution for a wide array of space-constrained and noise-sensitive applications.

The primary function of any LDO is to provide a well-regulated output voltage that remains stable even when the input voltage is only slightly higher than the desired output. This low dropout voltage is crucial for maximizing efficiency in battery-powered devices, where every millivolt counts to extend operational life. A typical dropout voltage for such a regulator might be as low as 150mV at full load, ensuring stable 3.3V output even as the battery voltage decays.

However, the standout feature of this class of regulator is its exceptionally high PSRR. PSRR measures the circuit's ability to reject ripple and noise originating from the input power supply, preventing these disturbances from propagating to the sensitive load. A high-PSRR LDO can achieve >60dB of rejection at 1kHz, effectively acting as a very clean, local power source for critical sub-circuits like RF transceivers, precision analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and oscillators in wireless communication systems (e.g., Wi-Fi, Bluetooth modules), and portable medical devices. This ensures signal integrity and reduces the bit-error-rate in data transmission.

The choice of the SOT-23-5 package is a significant advantage. Its ultra-small footprint is essential for modern PCB designs where real estate is at a premium, such as in wearables, IoT sensors, and handheld consumer electronics. Despite its diminutive size, this package offers a good balance between thermal performance and board space, allowing the regulator to dissipate heat effectively under its 50mA maximum output current.

Beyond core specifications, these regulators often incorporate vital protection features such as current limiting and thermal shutdown, safeguarding both the IC and the downstream components from damage during fault conditions. Some advanced versions may also include an enable/shutdown pin, providing designers with digital control to further minimize power consumption in standby modes.

ICGOODFIND: This 3.3V/50mA high-PSRR LDO in a SOT-23-5 package is an exemplary power management solution, masterfully balancing performance, size, and efficiency. Its superior noise rejection capabilities make it indispensable for powering the most sensitive components in compact, portable, and noise-averse electronic designs.

Keywords: Low-Dropout Regulator, High PSRR, SOT-23-5 Package, 3.3V Output, Power Management