MCP1754ST-3302E/MB 3.3V LDO Voltage Regulator Technical Specifications and Application Circuit Design

The MCP1754ST-3302E/MB 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. This device is engineered for applications requiring very low noise, high power supply ripple rejection (PSRR), and exceptional accuracy, making it a cornerstone component in power management design for modern electronic systems.

A standout feature of this LDO is its remarkably low dropout voltage, typically 178 mV at 150 mA load. This characteristic is critical for battery-powered applications, as it allows the regulator to continue providing a stable 3.3V output even as the battery voltage decays to a level very close to the output voltage, thereby maximizing battery life. Furthermore, the device boasts an impressively low quiescent current of 1.6 µA (typical), which minimizes the power drain when the system is in a standby or low-power mode.

The MCP1754ST-3302E/MB offers a maximum output current of 150 mA, sufficient to power microcontrollers, sensors, and various low-power ICs. Its high Power Supply Rejection Ratio (PSRR) of 70 dB at 1 kHz ensures that unwanted noise and ripple from the input power source are effectively attenuated, resulting in a clean and stable output voltage essential for noise-sensitive analog and RF circuits. The device also features a tight output voltage accuracy of ±0.5% under most operating conditions.

Typical Application Circuit Design

A standard application circuit for this LDO is straightforward, requiring only two external capacitors for stable operation. The basic schematic is as follows:

1. Input Capacitor (C_IN): A 1 µF ceramic capacitor placed between the input pin (VIN) and ground (GND) is recommended. This capacitor improves transient response and helps stabilize the input supply.

2. Output Capacitor (C_OUT): A 1 µF ceramic capacitor placed between the output pin (VOUT) and ground (GND) is required for stability. The regulator is specifically designed to be stable with low-ESR ceramic capacitors, which are ideal for minimizing board space and cost.

3. Bypass Capacitor (C_BYP): An optional 10 nF capacitor on the BYP pin to ground can be used to further reduce output noise. Leaving this pin unconnected defaults the device to its standard low-noise operating mode.

The input voltage is applied to the VIN pin, and the regulated 3.3V output is available on the VOUT pin. The SHDN (Shutdown) pin allows for logic-level control to turn the output on or off, reducing the quiescent current to 0.1 µA (typical) when driven low, which is a crucial feature for power-sensitive portable devices.

ICGOOODFIND: The MCP1754ST-3302E/MB stands out as an exceptional LDO regulator, offering an optimal blend of very low dropout voltage, ultra-low quiescent current, and high PSRR. Its simple design requirements and robust performance make it an ideal choice for extending battery life in portable electronics, cleaning up noisy power supplies, and providing a stable voltage rail for critical system components.

Keywords: LDO Regulator, Low Dropout Voltage, Low Quiescent Current, Power Supply Rejection Ratio (PSRR), Application Circuit