Bandgap reference circuit

摘要

A bandgap reference circuit is provided and which includes an operating voltage, a current mirror, a first p-channel metal-oxide semiconductor (PMOS) transistor and an amplifier. The current mirror is coupled to the operating voltage. The first PMOS transistor is coupled to the operating voltage and the current mirror. The amplifier is coupled to the current mirror and the first PMOS transistor. When the bandgap reference circuit is activated, the operating voltage starts to supply voltage such that the first PMOS transistor is turned on first. When the operating voltage is higher than a preset voltage level, the first PMOS transistor is turned off, in order to complete an start-up process.

主权项

1. A bandgap reference circuit, comprising:
an operating voltage; a current mirror coupled to the operating voltage, wherein the current mirror comprises:
a second PMOS transistor having a gate coupled to a source of the first PMOS transistor, and a source coupled to the operating voltage and a gate of the first PMOS transistor; anda third PMOS transistor having a gate coupled to the gate of the second PMOS transistor and the source of the first PMOS transistor and a source coupled to the operating voltage and the gate of the first PMOS transistor; a first PMOS transistor coupled to the operating voltage and the current mirror; and an amplifier coupled to the current mirror and the first PMOS transistor, wherein when the bandgap reference circuit is activated, the operating voltage is supplied such that the first PMOS transistor is turned on first, and when the operating voltage is higher than a preset voltage level, the first PMOS transistor is then turned off, in order to complete an start-up process.