The high-voltage linear regulator is used in the internal regulator circuit in the high-voltage power management chip to provide a stable power supply voltage input for the low-voltage module in the system. The circuit is mainly composed of two parts: the reference and the linear regulator.
The special features of high-voltage linear regulators are: including low-voltage domain operational amplifiers, high-voltage domain common source amplifiers and power stages;
The power stage includes a power tube and a first load; the power tube uses a high-voltage NMOS tube MN4; the first load uses a feedback resistor; the feedback resistor is used to sample the output voltage Vout of the high-voltage NMOS tube MN4, and The obtained feedback voltage Vfb is sent to the positive input terminal of the low-voltage domain operational amplifier;
Due to the narrow input voltage range, some applications are restricted. When the supply voltage is higher than 5V, most linear regulators with a typical input voltage range will collapse.
In addition, the output current of traditional linear regulators is very small, while high-performance FPGAs, microprocessors, or sensitive communication power supplies require high-current linear regulators. In order to better meet this demand, SCIENTEK ELECTRICAL manufactures A high-voltage linear regulator that is used to meet this demand.
The high-voltage linear regulator is different from the traditional linear regulator structure. It does not use the reverse breakdown voltage of the Zener diode to power the subsequent circuit. The high-voltage linear regulator introduces a pre-regulated bandgap reference circuit to generate accurate The reference voltage and to provide power to the error amplifier. Effectively reduce the chip area.
Wide-voltage linear regulators are required in IoT equipment powered by power sources such as lead-acid batteries or ACDC adapters to provide a stable power supply for the onboard 5V/3.3V components. Due to the voltage fluctuation of the lead-acid battery itself and when the adapter is connected with a long lead, the voltage fluctuation of the end-powered device will be relatively large. In this case, a linear regulator with a large withstand voltage margin and high PSRR is required.