MCP1754ST-3302E/CB 3.3V LDO Voltage Regulator: Key Features and Application Circuit Design
The MCP1754ST-3302E/CB is a high-performance, low-dropout (LDO) voltage regulator from Microchip Technology, designed to deliver a fixed 3.3V output from an input voltage range of 2.7V to 16V. It is engineered for applications requiring very low noise, high power supply rejection ratio (PSRR), and excellent line and load regulation, making it an ideal choice for powering sensitive analog and digital circuits.
Key Features
One of the most significant advantages of this LDO is its extremely low dropout voltage, typically 178 mV at 150 mA load. This allows it to continue regulating the output voltage even when the input voltage dips very close to 3.3V, maximizing efficiency and extending battery life in portable devices.
The regulator boasts a high Power Supply Rejection Ratio (PSRR), typically 70 dB at 1 kHz. This feature is critical for filtering out noise and ripple from the input power supply, ensuring a clean and stable output voltage for noise-sensitive components like RF transceivers, precision sensors, and audio codecs.
Furthermore, the MCP1754ST-3302E/CB offers a very low quiescent current of just 3.2 µA (typical) at no load. This minimal self-consumption is paramount for battery-powered applications where every microamp counts, significantly contributing to longer operational periods between charges.
Additional features include:
150 mA maximum output current
Excellent load and line transient response
Fixed 3.3V output voltage with ±0.5% accuracy
Thermal shutdown and current limit protection
Stable with a small, space-saving 1.0 µF ceramic output capacitor
Application Circuit Design
Implementing the MCP1754ST-3302E/CB is straightforward due to its minimal external component requirement. The basic application circuit is shown below.
A standard application circuit requires only two external capacitors.
1. Input Capacitor (C_IN): A 1.0 µF ceramic capacitor is recommended to be placed as close as possible to the VIN and GND pins. This capacitor improves transient response and stability, and helps suppress any input supply noise.
2. Output Capacitor (C_OUT): Similarly, a 1.0 µF ceramic capacitor is required on the output. It is crucial for maintaining loop stability and ensuring good transient performance. This capacitor must also be placed very close to the VOUT and GND pins of the regulator.
The shutdown (SHDN) pin is active low. Pulling this pin to ground places the regulator in a shutdown state, reducing the supply current to a mere 10 nA (typical). For normal operation, the SHDN pin should be connected directly to the input supply (VIN).
The MCP1754ST-3302E/CB stands out as an exceptional LDO regulator for modern electronic designs. Its combination of very low dropout voltage, high PSRR, and ultra-low quiescent current makes it a superior solution for a wide range of applications, including battery-powered IoT nodes, portable medical devices, automotive systems, and noise-sensitive measurement equipment. Its simple design-in process and robust protection features further solidify its position as a reliable and efficient power management component.
Keywords: LDO Regulator, Low Dropout Voltage, High PSRR, Low Quiescent Current, 3.3V Output
