A low-voltage power supply generating circuit, method and integrated circuit

Abstract

A low-voltage power generation circuit comprises a high voltage low-dropout linear regulator LDO circuit (51), a start-up circuit (52) and a low-voltage band gap reference circuit (53). In the start-up stage of the low-voltage power generation circuit, the start-up circuit (52) provides the power supply to the low voltage band gap reference circuit (53). The low voltage band gap reference circuit (53) outputs the corresponding reference voltage to the high voltage LDO circuit (51) by use of the power supply provided by the start-up circuit (52), so as to make the high voltage LDO circuit (51) normally start up. An integrated circuit and a low-voltage power generation method are also disclosed.

Description

technical field [0001] The invention relates to the field of power management, in particular to a low-voltage power generation circuit, method and integrated circuit (IC, Integrated Circuit). Background technique [0002] For power management ICs, the system usually requires that the input voltage range of the chip can vary from a few volts to tens of volts, and the chip is required to work normally at this time. For high-voltage power management chips, the general power solution is to divide the internal circuit into high-voltage circuit modules and low-voltage circuit modules; among them, the sub-circuits that interface with the input power are usually classified as high-voltage circuit modules, while internal references, clocks, etc. Sub-circuits are classified as low-voltage circuit modules, which can save the area of ​​the chip to the greatest extent and reduce the difficulty of chip design. [0003] For an IC powered by a high-voltage power supply, the power of the in...

AI Technical Summary

Problems solved by technology

The current technical solution is to directly transform the high-voltage power supply to obtain a low-voltage power supply. Although this type of solution can convert the high-voltage power supply into a low-voltage power supply, the low-voltage power supply generated is not stable enough and will change with the change of the load current; at the same time, the output is still Depending on the characteristics of the device, such as the voltage regulation value of the Zener tube and the threshold value of the N tube, etc., the output is not accurate, so it cannot be used in power chips with higher requirements

[0004] In order to solve the above problems, a method such as figure 1 The circuit shown uses a low dropout regulator (LDO, low dropout regulator) structure to obtain a stable low-voltage power supply, but this circuit needs to use a high-voltage depletion NMOS, which greatly increases the cost of the circuit; moreover, the circuit also The reference circuit and other auxiliary circuits of the LDO circuit are required, but the solution does not clarify how to solve the interdependence of the generated reference and the generated low-voltage power supply

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