Switching power supply and floating rail LDO cascaded hybrid power supply and application thereof

Abstract

The invention discloses a switching power supply and floating rail LDO cascaded hybrid power supply and application thereof, and the hybrid power supply comprises a switching power supply, an LDO and a voltage stabilization module. The switching power supply is used for generating voltage VDDH and voltage VDDL so as to provide power supply voltage for the LDO; the voltage VDDH is greater than the voltage VDDL; the voltage VDDH is output from the first output end of the switching power supply to the VDD end of the LDO; the voltage VDDL is output from the second output end of the switching power supply to the VSS end of the LDO; the voltage stabilizing module is connected with the second output end of the switching power supply and is used for stabilizing the voltage VDDL and providing a discharge path for the hybrid power supply; and the LDO is used for reducing ripples in the voltage VDDH, providing voltage for the load and accelerating transient response of the load. The topological structure of the floating power rail power supply LDO cascade switching power supply is adopted, and meanwhile the purposes of reducing output ripples, accelerating transient response and achieving high-voltage output are achieved; in addition, the floating power rail power supply LDO obviously reduces the requirement for voltage resistance of a transistor in the LDO, and the design difficulty and the process preparation difficulty of the LDO are reduced.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and more specifically relates to a hybrid power supply in which a switching power supply and a floating rail LDO are cascaded and an application thereof. Background technique [0002] In existing applications, when the voltage required by the load module to be powered is relatively high, a high-efficiency switching power supply is usually used directly to supply power to it, but the output voltage ripple of the switching power supply is usually large and the stability is poor; Taking the load module as a single photon avalanche diode (Single Photon Avalanche Diode, SPAD) as an example, the voltage range of the power supply to the SPAD is generally 10-30V, usually using a step-up DC-DC, a charge pump and other switching power supplies to directly supply power to it. At this time, the voltage ripple output by the switching power supply is relatively large, and the transient response to ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a hybrid power supply cascaded with a switching power supply and a floating-rail LDO and its application to solve the problem that the prior art cannot simultaneously achieve fast response and reduce Technical issues on the withstand voltage requirements of devices

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