DESCRIPTION
It directly supports Intel® SpeedStep™ processors for even longer battery life. The SC1476 fully supports Intel’s 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 thereby providing 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. The SC1476 operates from 3Vdc and 5Vdc and also features soft-start, an open-drain PWRGD signal with powergood blanking, and an enable input.
Semtech Corporation