MIC69302WR

The MIC69302WR is a low-noise linear voltage regulator that provides ultra-low output noise performance and features a wide input supply range and low quiescent current. This Application Note focuses on its application fields and working principle.

The MIC69302WR is specially designed for multiple industrial and computing applications, where low noise and long-term stability is essential. It can be used for medical and prosthetic devices, including implantable pacemakers, human and animal implants, scan and test equipment, instrumentation systems, and high-performance computing systems. It can also be used for low-voltage power supplies and high-voltage transducers.

The MIC69302WR is based on a linear low-dropout (LDO) regulator architecture and employs a voltage reference, series pass element, current sensing, and error amplifiers. It senses the drop across the series pass element and adjusts the output voltage accordingly. The voltage reference is maintained at a constant level independent of the input voltage and temperature.The series pass element and current sensing resistor are connected in series between the output and ground. The output voltage is set by the input voltage and is controlled by the series pass element. The current traversing the series pass element is sensed through the current sense resistor. The sensed current will be compared to the current reference voltage, which is generated by the voltage reference. The error amplifier will therefore compare the two voltages and drive the base of the pass transistor to regulate the output voltage.Moreover, the MIC69302WR has improved frequency compensation and ESR rejection, which allows it to maintain constant output voltage over the entire input supply and temperature range. The device also features short-circuit and over temperature protection, as well as internal reverse current protection, making it highly reliable for long-term operation.