A power-mode control circuitry is presented for power converters to
precisely control a maximum of the output power. The power-mode control
circuitry includes a filter to convert a switching current into an
average-current signal. A voltage divider attenuates an input voltage of
the power converter to an average-voltage signal. A multiplier produces a
power signal by multiplying the average-current signal with the
average-voltage signal. An error amplifier generates a programming signal
by comparing the power signal with a power-level threshold. The
programming signal further controls the switching signal for achieving
power-mode control.