Peak current mode controller

A power supply system comprising a power supply device and a peak current mode ‘PCM’ controller, the power supply device comprising a switch;

• and the peak current mode ‘PCM’ controller comprising:
• control logic arranged to produce a series of digital control values derived from a voltage sense signal corresponding to an output voltage of the power supply device;
• control logic arranged to produce a digital slope compensation value;
• a first digital to analogue converter ‘DAC’ arranged to receive the series of digital control values and output a corresponding analogue control voltage;
• a second DAC arranged to receive the digital slope compensation value and output a corresponding analogue slope compensation voltage;
• an analogue differential integrator arranged to:
• receive the analogue control voltage and the analogue slope compensation voltage;
• integrate the analogue slope compensation voltage;
• subtract the integrated slope compensation voltage from the analogue control voltage;
• and output a result of the subtraction as an analogue output voltage;
• a comparator arranged to compare the analogue output voltage to a voltage of an analogue current sense signal corresponding to an input current of the power supply device and produce an output signal when the analogue current sense signal voltage is equal to or exceeds the analogue output voltage;
• and control logic arranged to produce a drive signal opening the switch in response to the output signal.

A method of operating a peak current mode ‘PCM’ controller, the method comprising:

• producing a series of digital control values derived from a voltage sense signal by a control logic;
• producing a digital slope compensation value by a control logic;
• receiving the series of digital control values at a first digital to analogue converter ‘DAC’ and outputting a corresponding analogue control voltage from the first DAC;
• receiving the digital slope compensation value at a second DAC and outputting a corresponding analogue slope compensation voltage from the second DAC;
• receiving the analogue control voltage and the analogue slope compensation voltage at an analogue differential integrator;
• the analogue differential integrator integrating the analogue slope compensation voltage;
• the analogue differential integrator subtracting the integrated slope compensation voltage from the analogue control voltage;
• and the analogue differential integrator outputting a result of the subtraction as an analogue output voltage;
• comparing the analogue output voltage to a voltage of an analogue current sense signal at a comparator and producing an output signal when the analogue current sense signal voltage is equal to or exceeds the analogue output voltage;
• and producing a drive signal by a control logic in response to the output signal.