Control circuit and interleave power supply provided with same

Abstract

Provided are a control circuit for controlling an interleave power supply that is rarely affected by imbalance in parts and that is suited for mass production, and an interleave power supply provided with same. A clock generating unit generates a clock pulse with a prescribed frequency. A signal doubling unit generates a main-switch on-duration pulse signal on the basis of a main drive pulse signal that switching-drives a main switch of a main converter, and the clock pulse, and also generates a doubled duty-factor pulse signal that has doubled the duty factor compared to that of the main-switch on-duration pulse signal. An edge pulse generating unit generates a first edge pulse signal on the basis of the main drive pulse signal, and generates a second edge pulse signal on the basis of the doubled duty-factor pulse signal. A subordinate driving pulse signal generating unit generates a subordinate driving pulse signal such that the on-duration of the main switch and the on-duration of a subordinate switch become the same, on the basis of the first edge pulse signal and the second edge pulse signal.

Description

technical field [0001] The invention relates to a control circuit for controlling an interleave power supply which has less influence on component deviation and is suitable for mass production, and an interleave power supply including the control circuit. [0002] this application claims priority based on Japanese Patent Application No. 2011-252579 for which it applied to Japan on November 18, 2011, and uses the content here. Background technique [0003] As a conventional switching power supply, there is a patent document 1 figure 1 The disclosed interactive switching power supply. In this conventional alternating switching power supply, for example, two critical-type step-up chopping converters (converters) include switching on and off switching elements provided between the other end of the transformer (transformer) and ground. The control circuit for controlling, the control circuit of the first critical type boost chopper converter generates the switch of the first cr...

AI Technical Summary

Problems solved by technology

[0006] However, when using a control circuit that does not have a close relationship between the voltage of the FB terminal (VFB) and the on-time width (TON) of the switching element Q31, the first critical type step-up chopper converter and the second critical type In a step-up chopper converter, the on-time widths of the respective switch currents become unbalanced

As a result, the current critical action of the second critical step-up chopper converter can no longer be maintained, the power factor decreases, the output voltage fluctuation increases, the noise increases, and even the noise of the choke coil may increase

Therefore, in the above-mentioned conventional alternating switching power supply, since the conduction time widths of the switching currents of the first critical step-up chopper converter and the second critical step-up chopper converter cannot be automatically adjusted to be consistent , so screening may be required in mass production

Therefore, especially when it is a multi-stage current critical type alternating switching power supply using more than two critical type step-up chopper converters, there is a problem of difficulty in mass production

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