Band-gap reference circuit

Abstract

The invention discloses a band difference reference circuit, comprising: an absolute temperature proportional current generating circuit, the absolute temperature proportional current generating circuit can generate an absolute temperature proportional current, and the absolute temperature proportional current will increase as the temperature rises; A temperature complementary current generating circuit, the absolute temperature complementary current generating circuit can generate an absolute temperature complementary current, and the absolute temperature complementary current will decrease as the temperature rises; a node, the node can receive the absolute temperature proportional current and the absolute temperature complementary current; and, the first resistor is connected between the node and the ground terminal so that the superimposed absolute temperature proportional current and the absolute temperature complementary current pass through the first resistor to generate a reference voltage. The band difference reference circuit of the present invention can conform to the standard semiconductor process, and the band difference reference circuit can output accurate reference voltage and has nothing to do with the deviation of the semiconductor process.

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 figure 1 , which shows 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 effe...

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 Figure 5 The band difference reference circuit cannot provide 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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