Step-down circuit for bandgap reference voltage circuit

Abstract

The invention discloses a step-down circuit for a bandgap reference voltage circuit. The step-down circuit comprises a first transistor, a current mirror circuit, a voltage division circuit, an output resistor and a fourth transistor, the first transistor receives an initial bandgap reference voltage from the bandgap reference voltage circuit. The voltage division circuit is connected to the first transistor and a ground terminal, and has a voltage division node for outputting a first divided voltage. The fourth transistor is connected to the output resistor and a ground terminal and receives the first partial voltage. The current mirror circuit forms a first current on the voltage division circuit through the first transistor, and mirrors the first current to the output resistor to form a second current. The voltage division circuit and the output resistor have a first temperature characteristic, and the first transistor and the fourth transistor have a second temperature characteristic, so that the output node generates a reference voltage which is irrelevant to the temperature and is lower than the initial energy gap reference voltage.

Description

technical field [0001] The present invention relates to a step-down circuit for a bandgap reference voltage circuit, in particular to a step-down circuit for a bandgap reference voltage circuit that can generate a reference voltage that is independent of temperature and lower than the initial bandgap reference voltage . Background technique [0002] Generally, the voltage generated by the bandgap reference voltage circuit is around 1.25V. Therefore, if you want to use the voltage of the bandgap reference voltage circuit to generate a temperature-independent and lower than 1V reference voltage, you can use a variety of circuits to achieve it. [0003] For example, buffers and resistors can be used to step down the bandgap reference voltage, however, the size and power consumption are relatively large. Alternatively, a voltage follower can be used to step down the bandgap reference voltage, but the generated reference voltage has poor temperature characteristics. [0004] In...

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Problems solved by technology

[0003] For example, buffers and resistors can be used to step down the bandgap reference voltage, however, the size and power consumption are large

Alternatively, a voltage follower can be used to step down the bandgap reference voltage, but the resulting reference voltage has poor temperature characteristics

[0004] In addition, there is also a direct voltage division of the bandgap reference voltage through a divider resistor. However, in the case of a small resistance, it may affect the characteristics of the bandgap reference voltage, and in the case of a large resistance, it will increase the circuit. usage area

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