Patent ID: 8427123

Claim:
A switch mode power supply (SMPS) using pulse-density modulation (PDM) control or pulse-width modulation (PWM) control, said SMPS comprising: a switch mode power supply (SMPS) converter; and a load determination circuit for detecting when a load current reaches a transition current value, comprising: a PWM error generator generating a PWM demand signal, a threshold generator generating a PDM demand signal; a hysteretic comparator receiving a current sense signal and being operable to enable the PWM error generator and the PDM threshold generator dependent on the current sense signal; and a fixed frequency oscillator and power circuit driver receiving th PWM demand signal and the PDM demand signal, wherein, when the PWM error generator and PDM threshold generator are enabled, the fixed frequency oscillator and power circuit driver outputs fixed frequency pulses or pulse width modulated pulses having said fixed frequency depending on whether the PWM error generator generates a duty cycle demand signal.