onsemi NCP5501DT50RKG: 50 mA Low-Dropout Voltage Regulator

In the realm of power management for portable and space-constrained electronic devices, low-dropout (LDO) linear regulators remain a cornerstone technology. The onsemi NCP5501DT50RKG is a prime example, offering a compact, efficient, and reliable solution for applications requiring a stable 50 mA low-dropout voltage regulator. This article provides a detailed look at its datasheet specifications, pinout configuration, and typical application circuits.

Datasheet Overview and Key Features

The NCP5501 series is designed for battery-powered applications, providing a fixed output voltage with high accuracy and very low power consumption. The "DT50RKG" variant specifically denotes a device in a SOT-23-5 package with a fixed 5.0V output.

Key specifications from the datasheet include:

Output Current: Up to 50 mA.

Dropout Voltage: Typically 120 mV at 30 mA load, which is exceptionally low. This allows the regulator to continue providing a regulated output even when the input voltage dips very close to the output level, maximizing battery life.

Output Voltage Accuracy: ±2% under specified conditions.

Low Quiescent Current: Typically 85 µA, which is crucial for extending battery life in always-on applications.

Low Noise Output: Features an internal compensation capacitor, eliminating the need for an external component and providing a clean, stable output.

Protection Features: Includes built-in over-current protection and thermal shutdown, safeguarding the IC and the downstream circuitry from damage.

Pinout Configuration

The NCP5501DT50RKG is housed in a 5-pin SOT-23 package. Its pinout is as follows:

Pin 1 (IN): Input Voltage Pin. A bypass capacitor (typically 1 µF) should be connected between this pin and ground.

Pin 2 (GND): Ground Pin.

Pin 3 (ENABLE): Enable Pin. A high logic level (>1.5V) turns the regulator ON. This pin can be tied directly to IN if the shutdown feature is not used.

Pin 4 (NC): No Connection.

Pin 5 (OUT): Regulated Output Voltage Pin. A small output capacitor (≥1 µF) is required for stability.

Application Circuits

The NCP5501DT50RKG is simple to implement, requiring only two external capacitors for basic operation.

1. Standard Application Circuit: The most common setup involves connecting a 1 µF (or greater) ceramic capacitor from the IN pin to GND and a 1 µF (or greater) ceramic capacitor from the OUT pin to GND. The ENABLE pin can be controlled by a microcontroller for power sequencing or tied directly to IN for always-on operation.

2. Load Switch with Microcontroller: The ENABLE pin is a key feature for power management. It can be driven directly by a GPIO pin from a microcontroller (µC), allowing the µC to turn entire sections of a circuit on or off, drastically reducing overall system power consumption during standby or sleep modes.

3. Powering Noise-Sensitive Components: Due to its low-noise output characteristics, the NCP5501 is an excellent choice for providing clean power to sensitive components like analog sensors, RF modules, or audio codecs, preventing noise from the main power rail from degrading performance.

ICGOODFIND Summary

The onsemi NCP5501DT50RKG is a highly efficient and robust 50 mA low-dropout voltage regulator ideal for a vast array of portable and battery-operated devices. Its extremely low dropout voltage and low ground current make it perfect for extending battery life, while its integrated protection features and simple two-capacitor design ensure reliable and easy implementation. Whether used for powering microcontrollers, sensors, or as a local noise filter, this LDO delivers performance and stability in a minuscule footprint.

Keywords: Low-Dropout Regulator, LDO, NCP5501, Power Management, Onsemi