The SC450 PowerStep IVTM IC is a single chip high-performance Hysteretic PWM controller. With its integrated SmartDriverTM, it powers advanced IMVP-IVTM and IMVP4+TM processors. The SC450 features extended Intel Mobile Voltage Positioning (IMVPTM) to increase battery life by reducing the voltage at the processor when it is heavily loaded. It directly supports Intel's SpeedStep processors for even longer battery life. The SC450 fully supports the Intel Geyserville-III core voltage specification. It provides direct "deeper sleep" mode and boot voltage support. Automatic "power-save" is present to prevent negative current flow in the low-side FET during light loading conditions, saving even more power. The high side driver initially turns on with a weak drive to reduce ringing, EMI, and capacitive turn-on of the low side. A 6-bit DAC, accurate to 0.85%, sets the output voltage reference, and implements the 0.700V to 1.708V range required by the processor. The hysteretic converter uses a comparator without an error amplifier, and therefore provides the fastest possible transient response, while avoiding the stability issues inherent to classical PWM controllers. The DAC is externally slew rate limited to minimize transient currents and audible noise.