Abstract: A slope compensation module provides slope compensation of a switched-mode power supply using current mode control. The slope control unit comprises a capacitor coupled between an input and an output of the slope control unit, a switch for discharging the capacitor and a constant current source for charging the capacitor. Slope compensation parameters may be changed during operation with a programmable constant current source. The slope compensation module may also function as an analog sawtooth waveform frequency generator, and as an analog pulse width modulation (PWM) generator. Charging the capacitor generates a linearly decreasing (negative slope) ramp voltage for modulating a feedback error voltage into a slope compensated feedback error voltage. Capacitor charging may be controlled from a pulse width modulation signal. Opening of the switch may be programmably delayed, and a minimum closed time thereof may also be programmed during operation of the slope compensation module.

Abstract: A slope compensation module provides slope compensation of a switched-mode power supply using current mode control. The slope control unit comprises a capacitor coupled between an input and an output of the slope control unit, a switch for discharging the capacitor and a constant current source for charging the capacitor. Slope compensation parameters may be changed during operation with a programmable constant current source. The slope compensation module may also function as an analog sawtooth waveform frequency generator, and as an analog pulse width modulation (PWM) generator. Charging the capacitor generates a linearly decreasing (negative slope) ramp voltage for modulating a feedback error voltage into a slope compensated feedback error voltage. Capacitor charging may be controlled from a pulse width modulation signal. Opening of the switch may be programmably delayed, and a minimum closed time thereof may also be programmed during operation of the slope compensation module.

Abstract: A current limited voltage supply including a transistor and a capacitor is provided for powering digital logic cells of an integrated circuit. The transistor is connected in a current mirror configuration, such that a constant reference current is mirrored through the transistor to create a first supply current. The transistor is coupled to the digital logic cells and the capacitor. The first supply current is used to charge the capacitor while the digital logic cells are not switching. While the digital logic cells are switching, the capacitor discharges to the digital logic cells, thereby providing the digital logic cells with sufficient energy to implement high-speed switching. The capacitor minimizes voltage fluctuations within in the current limited voltage supply, such that analog circuitry can be reliably powered from a different branch of the same current mirror circuit.

Abstract: A current limited voltage supply including a transistor and a capacitor is provided for powering digital logic cells of an integrated circuit. The transistor is connected in a current mirror configuration, such that a constant reference current is mirrored through the transistor to create a first supply current. The transistor is coupled to the digital logic cells and the capacitor. The first supply current is used to charge the capacitor while the digital logic cells are not switching. While the digital logic cells are switching, the capacitor discharges to the digital logic cells, thereby providing the digital logic cells with sufficient energy to implement high-speed switching. The capacitor minimizes voltage fluctuations within in the current limited voltage supply, such that analog circuitry can be reliably powered from a different branch of the same current mirror circuit.