FastPWM

// sets up a 31.25 kHz PWM on pin 11
void setup()
{
  pinMode(11, OUTPUT);
  TCCR2A = _BV(COM2A1) | _BV(COM2B1) | _BV(WGM21) | _BV(WGM20);
  TCCR2B = _BV(CS20);
}

void loop()
{
  OCR2B = 127;  // put any 8 bit value here
}