Control device, digital control power supply, and control method

摘要

In a digital control power supply, a mode control unit measures a first frequency and a second frequency for a difference between a second digital value and a target value. Based on the measured first frequency and second frequency and a predetermined threshold set to the first and second frequencies, the mode control unit determines whether an amplification factor for use in amplification processing by an amplifier is maintained at a current amplification factor or is changed to an amplification factor which is larger or smaller by 1 than the current amplification factor. This contributes to an improvement in noise resistance of the digital control power supply and prevents an output voltage from being unstable.

主权项

1. A control device that performs digital control of an output of a power supply, comprising:
a mode control unit that selects one of a plurality of mode signals respectively corresponding to a plurality of different amplification factors; an amplifier that obtains an amplified output by amplifying the output of the power supply with an amplification factor corresponding to the mode signal selected by the mode control unit; an A/D converter that performs an A/D conversion on the amplified output to obtain a first digital value; and an output control unit that converts the first digital value into a second digital value representing the output of the power supply as a predetermined bit accuracy, obtains a difference between the second digital value and a target value, and controls the output of the power supply according to the difference, the target value being a digital value for a target output of the power supply and represented as the predetermined bit accuracy, wherein when the difference is set as an index value, the mode control unit is configured to: select the mode signal based on the index value and a difference absolute value range that is a range of an absolute value of the difference set to each of the plurality of mode signals, the absolute value of the difference included in the difference absolute value range set to the mode signal increasing as the amplification factor corresponding to the mode signal decreases; measure a first frequency indicating the number of occurrences of the absolute value of the index value being equal to or less than a lower limit of the difference absolute value range set to a current mode signal, and a second frequency indicating the number of occurrences of the absolute value of the index value exceeding an upper limit of the difference absolute value range set to the current mode signal; maintain the current mode signal when the first frequency is less than a first threshold and the second frequency is less than a second threshold; select the mode signal corresponding to an amplification factor which is larger by 1 than the amplification factor corresponding to the current mode signal, when the first frequency is equal to or more than the first threshold; and select the mode signal corresponding to an amplification factor which is smaller by 1 than the amplification factor corresponding to the current mode signal, when the second frequency is equal to or more than the second threshold.