Band-gap reference circuit

Abstract

The invention discloses a belt difference reference circuit which comprises an absolute temperature proportion current generating circuit, an absolute temperature complementary current generating circuit, a node and a reference voltage; wherein the absolute temperature proportion current generating circuit can generate absolute temperature proportion current which can increase with the growth of temperature; the absolute temperature complementary current generating circuit can generate absolute temperature complementary current which can decrease with the growth of temperature; the node can receive the absolute temperature proportion current and the absolute temperature complementary current; a first resistance is connected between the node and a ground terminal; therefore, the absolute temperature proportion current and the absolute temperature complementary current both of which are overlapped can generate reference voltage through the first resistance. The belt difference reference circuit in the invention can conform to standard semiconductor technique; furthermore, the belt difference reference circuit can output accurate reference voltage without the deviation relative to semiconductor technique.

Description

technical field [0001] The invention relates to a bandgap reference circuit, and in particular to a bandgap reference circuit with low power supply voltage. Background technique [0002] As we all know, the function of the band difference reference circuit is to provide a stable reference voltage (Vref) that does not change with the process, temperature, and power supply voltage. Therefore, it is widely designed in many circuits in the field of hybrid circuits. For example, a voltage regulator (Voltage Regulator), a digital-to-analog circuit, and a low-drift amplifier (Low Drift Amplifier). [0003] Please refer to FIG. 1 , which is a schematic diagram of a known band difference reference circuit composed of a PMOS field effect transistor, a PNP bipolar transistor, and an operational amplifier. In general, the band difference reference circuit includes a mirror circuit (Mirroring Circuit) 12, an operational amplifier (15, and an input circuit 20. Three PMOS field effect tra...

AI Technical Summary

Problems solved by technology

[0031] Due to the deviation of the semiconductor process, the reference voltage (Vref) provided by the band difference reference circuit will produce an error of about ±15%, resulting in the band difference reference circuit of Figure 5 being unable to provide an accurate reference voltage (Vref)

Therefore, how to improve the offset of the known semiconductor process and cause the problem that the band difference reference circuit cannot provide an accurate reference voltage (Vref) is the main purpose of the present invention

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