MCP1703AT-3302E/MB 3.3V LDO Voltage Regulator Technical Specifications and Application Circuit Design

The MCP1703AT-3302E/MB is a popular CMOS low-dropout (LDO) voltage regulator from Microchip Technology, designed to deliver a fixed 3.3V output from an input voltage source up to 16V. Renowned for its very low quiescent current and low dropout voltage, it is an ideal choice for battery-powered and power-sensitive applications.

A key strength of this LDO is its exceptionally low quiescent current, typically just 2.0 µA during operation. This minimal self-consumption makes it perfect for devices that demand long battery life, such as wireless sensors, IoT nodes, and portable medical equipment. Furthermore, its low dropout voltage of 178 mV (typical at 250 mA load) ensures stable 3.3V regulation even as the input voltage approaches the output level, maximizing energy efficiency from batteries.

The regulator offers a maximum output current of 250 mA, sufficient for powering microcontrollers, sensors, and other low-power ICs. It incorporates vital protection features including overcurrent protection (OCP) and thermal shutdown, safeguarding both the regulator and the load circuitry under fault conditions. The device is stable with a small, space-saving 1.0 µF ceramic output capacitor, which reduces the overall solution size and bill-of-materials cost.

Typical Application Circuit Design

A standard application circuit for the MCP1703AT-3302E/MB is straightforward, requiring only a few external components.

1. Input Capacitor (C_IN): A 1.0 µF to 10 µF ceramic capacitor should be placed between the input pin (VIN) and ground (GND). This capacitor improves transient response and stability, and it should be located as close as possible to the regulator pins.

2. Output Capacitor (C_OUT): A 1.0 µF ceramic capacitor is required between the output pin (VOUT) and ground for stability. Using a capacitor with low Equivalent Series Resistance (ESR) is recommended.

3. Input Voltage (VIN): The input supply, which must be higher than 3.3V + V_DROPOUT, is connected to the VIN pin. For reliable operation, ensure the input voltage does not exceed the 16V absolute maximum rating.

The basic circuit is shown below:

```

VIN (2.7V-16V) ────╭───╮───── 3.3V VOUT

│ │

C_IN ═╡ ╞─ C_OUT ══╗

│ │ ║

GND ────────────────╯───╰───────────╝

(MCP1703AT-3302E/MB)

```

ICGOODFIND Summary

The MCP1703AT-3302E/MB stands out as an ultra-low-quiescent-current LDO regulator, providing a simple and reliable solution for generating a stable 3.3V rail. Its exceptional efficiency, minimal external component requirement, and built-in protections make it a superior choice for space-constrained and battery-dependent designs across consumer, industrial, and automotive applications.

Keywords:

1. Low Dropout (LDO)

2. Low Quiescent Current

3. 3.3V Voltage Regulator

4. Thermal Shutdown

5. Application Circuit