MCP1824T-3302E/OT 3.3V LDO Voltage Regulator: Features and Application Circuit Design
The MCP1824T-3302E/OT is a high-performance, low-dropout (LDO) voltage regulator from Microchip Technology, designed to deliver a fixed 3.3V output from a higher input voltage source. It is renowned for its excellent line and load regulation, low noise, and high power supply ripple rejection, making it an ideal choice for powering sensitive digital and analog circuits in a wide range of applications, from consumer electronics to industrial systems.
Key Features
This LDO boasts a set of impressive characteristics that set it apart:
High Output Accuracy: The device maintains an output voltage accuracy of ±1%, ensuring a stable and reliable power supply for downstream components like microcontrollers, sensors, and communication modules (Wi-Fi, Bluetooth).
Low Dropout Voltage: With a typical dropout voltage of 210 mV at 300 mA, it can continue to regulate the 3.3V output even when the input voltage drops very close to this value. This feature is crucial for battery-powered applications, as it extends battery life by allowing operation until the battery is nearly depleted.
Low Quiescent Current: The regulator consumes a very low ground current during operation, which significantly enhances efficiency, especially in always-on or standby-mode applications.
Excellent Transient Response: It responds quickly to sudden changes in load current, minimizing output voltage deviations and ensuring system stability.
Protection Features: The IC includes built-in overcurrent protection and thermal shutdown, safeguarding both the regulator itself and the connected load from damage under fault conditions.
Small Form Factor: The SOT-23-5 package is extremely compact, making it perfect for space-constrained PCB designs.
Typical Application Circuit Design
Designing a power supply circuit with the MCP1824T-3302E/OT is straightforward, requiring only a few external components. A basic application circuit is shown below.
```
VIN (4.0V - 6.0V)
|
+---[C_IN]---+
| |
| GND
|
VIN (3) --- MCP1824T-3302E/OT --- VOUT (2) ---+--- VOUT (3.3V)
| | |
GND (1) [C_OUT] |
| | [Load]
| GND |
| GND
```
Input Capacitor (C_IN): A 1 µF to 10 µF ceramic capacitor is required between the VIN pin and ground. This capacitor improves the regulator's transient response and stability, and helps to filter out noise on the input supply rail. It should be placed as close as possible to the IC's VIN and GND pins.
Output Capacitor (C_OUT): A 1 µF ceramic capacitor is sufficient between the VOUT pin and ground to ensure stability. Using a low-ESR (Equivalent Series Resistance) ceramic capacitor is highly recommended. Like the input capacitor, it must be placed close to the regulator for optimal performance.
Load: The regulated 3.3V output can supply up to 300 mA of continuous current to the connected load.
Design Considerations:
1. Input Voltage Range: Ensure the input voltage (VIN) is always higher than VOUT + VDROP. For a 3.3V output, the absolute maximum input voltage is 6.0V, but the practical input range is typically from ~3.5V to 5.5V for standard 5V systems.
2. Power Dissipation: Calculate power dissipation as (VIN - VOUT) IOUT. Ensure the power dissipation does not exceed the package limits, considering the thermal resistance. For high current or high input voltage applications, proper PCB layout with a thermal relief pad is essential.
3. PCB Layout: For best performance, use a solid ground plane and keep the traces connecting the input and output capacitors to the IC as short and wide as possible to minimize parasitic inductance and resistance.
The MCP1824T-3302E/OT stands out as an exceptionally robust and easy-to-use LDO solution for 3.3V power rails. Its combination of high accuracy, low dropout voltage, and comprehensive protection features, all housed in a miniature package, makes it a superior choice for designers seeking to create efficient, compact, and reliable electronic products. Its minimal external component count simplifies the design process and reduces the overall Bill of Materials (BOM) cost.
Keywords:
1. LDO Voltage Regulator
2. 3.3V Output
3. Low Dropout Voltage
4. SOT-23-5 Package
5. Application Circuit
