onsemi NCV5661MN33T2G 3V LDO Voltage Regulator: Datasheet, Pinout, and Application Circuit Guide
The onsemi NCV5661MN33T2G is a robust and reliable low-dropout (LDO) linear voltage regulator designed to deliver a fixed 3.3V output at a maximum current of 50 mA. As part of onsemi's automotive-qualified portfolio, this IC is engineered for the demanding environments of automotive applications, making it an excellent choice for powering sensitive electronics in systems requiring stable and clean voltage.
Datasheet Overview and Key Specifications
The datasheet for the NCV5661MN33T2G reveals its core electrical characteristics and robustness. Key specifications include:
Output Voltage: Fixed at 3.3V with a typical accuracy of ±2%.
Maximum Output Current: 50 mA.
Dropout Voltage: Typically 300 mV at 30 mA load current, ensuring efficient operation even when the input voltage is very close to the output level.
Input Voltage Range: 3.5V to 45V. This exceptionally wide range allows it to handle large transients and is ideal for automotive environments where load dump and other voltage spikes are common.
Low Quiescent Current: Typically 50 µA, which is crucial for battery-powered applications to minimize drain.
Protection Features: The device includes internal current limiting and thermal shutdown for comprehensive protection against overloads and overtemperature conditions.
AEC-Q100 Qualified: This certification confirms its suitability for use in automotive electronics.
Pinout Configuration
The NCV5661MN33T2G is available in a space-saving DFN-8 (3x3mm) package. Its pinout is straightforward:
Pin 1 (IN): Input Voltage. This pin should be connected to the input power source and requires a suitable input capacitor for stability.
Pin 2 (GND): Ground.
Pin 3 (ENABLE): Enable Pin. Applying a logic high (> 2.0V) enables the regulator's output. Pulling this pin low (< 0.8V) places the device in a low-power shutdown mode.
Pin 4 (NC): No Connection.
Pins 5-8 (OUT): Output Voltage. These pins are internally connected and must be tied together on the PCB to provide the regulated 3.3V output.
Typical Application Circuit Guide
A standard application circuit for the NCV5661MN33T2G is simple to implement, requiring only a few external components for stable operation.
1. Input Capacitor (C_IN): A 1 µF to 10 µF ceramic capacitor should be placed as close as possible to the IN pin and GND. This capacitor is vital for stabilizing the input supply and improving transient response.
2. Output Capacitor (C_OUT): A 1 µF ceramic capacitor is recommended between the OUT pin and GND. It ensures output stability and improves loop response. For optimal performance, a low-ESR (Equivalent Series Resistance) capacitor is advised.
3. Enable Control: The ENABLE pin can be driven directly by a microcontroller's GPIO pin for power sequencing or to turn off the regulator to save power. If this feature is not required, the pin can be tied directly to the IN pin to enable the device permanently.
The circuit's operation is simple: an unregulated input voltage within the 3.5V to 45V range is applied to the IN pin. The internal circuitry of the LDO then provides a clean, stable, and precisely regulated 3.3V output at the OUT pin, capable of sourcing up to 50 mA of current to the load.
The onsemi NCV5661MN33T2G stands out as an exceptionally robust and simple solution for low-current, low-noise voltage regulation, particularly in harsh electrical environments like automotive systems. Its wide input voltage range and integrated protection features make it a reliable building block for powering microcontrollers, sensors, and other core logic components. For designers seeking an AEC-Q100 qualified LDO that combines ease of use with high performance, this regulator is a superior choice.
Keywords: LDO Regulator, Automotive Grade, 3.3V Output, Wide Input Voltage, AEC-Q100
