MCP1826ST-3302E/DB 3.3V LDO Voltage Regulator: Technical Specifications and Application Circuit Design
The MCP1826ST-3302E/DB 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. Renowned for its high accuracy, low noise, and excellent transient response, it is an ideal choice for powering sensitive digital cores, analog circuits, and RF modules in a wide array of applications, including consumer electronics, industrial equipment, and Internet of Things (IoT) devices.
Key Technical Specifications
The MCP1826S series is characterized by its robust electrical performance. Key specifications for the -3302E/DB variant include:
Output Voltage: Fixed at 3.3V with a high accuracy of ±1% under most operating conditions.
Output Current: Capable of delivering a continuous 1.0A output current.
Dropout Voltage: Features a very low typical dropout voltage of 340 mV at 1A load, maximizing efficiency and allowing operation with input voltages as low as ~3.64V.
Input Voltage Range: Operates from 2.3V to 6.0V, making it compatible with common power sources like 5V rails and 3.7V Li-ion batteries.
Quiescent Current: Draws a low typical ground current of 120 µA during operation, which is crucial for battery-powered applications. It also features a low shutdown current.
Protection Features: Includes integrated overcurrent protection and thermal shutdown, safeguarding the regulator and the load under fault conditions.
Package: Offered in a 3-pin SOT-223 package (DBV suffix), which provides a good balance between size and thermal performance.
Typical Application Circuit Design
Implementing the MCP1826ST-3302E/DB is straightforward, but proper design is critical for stable and reliable operation. A standard application circuit is shown below.
```
VIN (2.7V to 6.0V)
│
├───┤╱╲├───┬───────╮
│ [1-10Ω] │ │
│ │ ┌┴┐
=== C_IN │ │ │ Load
0.1µF to 10µF === C_OUT │ │
│ 10µF │ │
│ │ └┬┘
│ │ │
─┴─ GND ─┴─ GND ─┴─ GND
```
1. Input Capacitor (C_IN): A 1.0µF to 10µF ceramic capacitor placed close to the VIN pin is essential for stability and filtering input noise. A low-ESR (Equivalent Series Resistance) ceramic capacitor is highly recommended.
2. Output Capacitor (C_OUT): The regulator is designed for stability with low-ESR ceramic output capacitors. A minimum 10µF ceramic capacitor on the output is required to ensure loop stability and to improve transient response. This capacitor must also be placed as close as possible to the VOUT and GND pins of the IC.
3. PCB Layout Considerations:
Thermal Management: For continuous 1A load current, effective PCB layout is vital for heat dissipation. The SOT-223 package features a metal tab that must be soldered to a large copper pour (a thermal pad) on the PCB. This pad should be connected to a ground plane using multiple thermal vias to act as a heatsink.
Minimize Trace Length: Keep the input and output capacitor loops short and direct to minimize parasitic inductance and ensure optimal performance.
The MCP1826ST-3302E/DB stands out as a highly reliable and efficient solution for 3.3V power regulation. Its combination of high output current, low dropout voltage, and robust protection features makes it a superior choice for designers seeking to optimize both performance and board space. Proper attention to capacitor selection and PCB thermal design is the key to unlocking its full potential in any application.
Keywords:
1. Low-Dropout (LDO) Regulator
2. 3.3V Output
3. 1A Output Current
4. Thermal Shutdown Protection
5. Application Circuit
