MCP1702T-3302E/MB 3.3V LDO Voltage Regulator: Technical Specifications and Application Circuit Design

The MCP1702T-3302E/MB is a popular CMOS low-dropout (LDO) voltage regulator from Microchip Technology, renowned for its high efficiency, low quiescent current, and excellent stability. Designed to deliver a fixed 3.3V output at up to 250 mA of current, it is an ideal choice for a wide range of battery-powered and space-constrained applications, including IoT devices, portable electronics, and microcontroller power supplies.

A key advantage of this LDO is its remarkably low quiescent current, typically just 2.0 µA during operation. This feature is critical for extending battery life in always-on applications. Furthermore, it boasts a very low dropout voltage—typically 178 mV at 250 mA—allowing it to continue regulating the 3.3V output even as the input voltage dips close to 3.47V, maximizing the usable energy from a draining battery.

The device is designed for stability with just a 1.0 µF ceramic output capacitor, simplifying board design and reducing both component count and physical footprint. Its SOT-23-3 package (MB) is miniature and perfect for compact PCB layouts. Additional built-in protection features include current limit and thermal shutdown, safeguarding the regulator and the downstream load under fault conditions.

Typical Application Circuit Design

A standard application circuit for the MCP1702T-3302E/MB is straightforward, requiring only a few external components.

1. Input Capacitor (C_IN): A 1 µF to 10 µF ceramic capacitor placed between the input voltage (VIN) pin and ground is recommended to improve transient response and stability. It should be located as close as possible to the regulator's pins.

2. Regulator IC: The MCP1702T-3302E/MB. Pin 1 (VIN) connects to the input supply, Pin 2 (GND) is grounded, and Pin 3 (VOUT) delivers the regulated 3.3V output.

3. Output Capacitor (C_OUT): A 1.0 µF ceramic capacitor from the VOUT pin to ground is required for stability. Larger values (e.g., 2.2 µF or 4.7 µF) can be used to further improve transient performance.

The input voltage must remain within the specified range of 2.7V to 13.2V and must always be at least 0.2V above the 3.3V output for proper regulation. This simple yet robust circuit provides a clean, stable 3.3V rail from a higher, unregulated input source like a Li-ion battery (3.7V-4.2V) or a 5V USB bus.

ICGOOODFIND Summary:

The MCP1702T-3302E/MB stands out as an exceptionally efficient and simple solution for generating a stable 3.3V power rail. Its combination of ultra-low quiescent current, low dropout voltage, and minimal external component requirements makes it a superior choice for power-conscious and space-limited designs across consumer and industrial markets.

Keywords:

1. LDO Voltage Regulator

2. Low Quiescent Current

3. 3.3V Output

4. Dropout Voltage

5. Application Circuit