Reference voltage generating circuit applicable to wide supply voltage range

Abstract

The invention discloses a reference voltage generating circuit applicable to a wide supply voltage range. The circuit includes an initial reference voltage generating circuit, a capacitance bleeder circuit, a first switch, a reset circuit, a reset circuit time delay control circuit, a second switch and a third switch; the initial reference voltage generating circuit is used for generating initialreference voltage; the capacitance bleeder circuit is used for generating capacitance reference voltage; the first switch is used for supplying electricity to the initial reference voltage generatingcircuit and the capacitance bleeder circuit when the circuit is powered on or after the reset operation is carried out; the reset circuit is used for resetting the initial reference voltage generatingcircuit and the capacitance bleeder circuit when it is detected that supply voltage enabling signals are frequently switched; the reset circuit time delay control circuit is used for generating switching detection signals to control the operation of the reset circuit when the supply voltage enabling signals are frequently switched since supply voltage is frequently switched between the low voltage and the high voltage; the second switch is used for outputting the initial reference voltage in a voltage division mode when the reference voltage needs to be refreshed after the initial reference voltage is generated; the third switch is used for enabling the initial reference voltage generating circuit to generate Vref before the reference voltage is refreshed, and switching off the initial reference voltage generating circuit after the refreshing operation is completed.

Description

Technical field [0001] The present invention relates to a reference voltage generating circuit, in particular to a reference voltage generating circuit suitable for a wide power supply voltage range. Background technique [0002] Low-power design is favored in bank cards, MCUs and other fields. One way to reduce power consumption is to reduce system power consumption by reducing the power supply voltage. The flexible use of low-voltage slow reading and high-voltage fast reading can be effective Reduce system requirements for power consumption. The embedded flash memory IP that works at low voltage can reduce the design difficulty of peripheral circuits, and at the same time enable the entire system to work in low power consumption mode. [0003] Low power design requirements for power supply voltage: [0004] When LVE=0, it works at VDD=1.5V+ / -10% [0005] When LVE=1, it works at VDD=1.2V+ / -10% [0006] figure 1 It is a circuit diagram of a traditional reference voltage generating ci...

AI Technical Summary

Problems solved by technology

[0010] However, the above circuit has the disadvantage that the Vref and Vcap voltages cannot be kept equal under different supply voltages (1.2V or 1.5V)

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