SC1476 Portable IMVP-IV Dual Phase Power Supply Controller POWER MANAGEMENT Description Features IMVP-IV compliant single chip solution High speed hysteretic controller 6 bit VID programmable output Integrated drivers with soft high side turn-on Programmable softstart Programmable boot voltage Programmable DeeperSleep voltage Dynamic phase current matching Under-voltage lockout on VccA Over-voltage protection on CORE Current Limit protection on CORE Thermal protection Powergood flag with blanking during VID or DeeperSleep mode changes Automatic powersave at light load Slew rate limited DAC TSSOP-38 package The SC1476 PowerStep™ IV IC is a single chip high-performance hysteretic PWM controller. With its integrated SmartDriver™, it powers advanced IMVP-IV processors. The SC1476 features extended Intel® Mobile Voltage Positioning (IMVP) to increase battery life by reducing the voltage at the processor when it is heavily loaded. 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. Applications Notebook and Laptop computers Requests for a complete datasheet and additional product information should be directed to [email protected] The SC1476 operates from 3Vdc and 5Vdc and also features soft-start, an open-drain PWRGD signal with powergood blanking, and an enable input. Programmable current limiting shuts down the SC1476 after 32 current limit pulses. In addition, it comes in a space-saving TSSOP-38 package. Typical Application Circuit +V_IN +V_5 Smart Driver Power Control Signals Extended IMVP Logic Lo +VCORE Rcs 0.600V-1.75V Up to 40A PWM Controller SC1474 Dual Phase Extended IMVP CONTROLLER VVID I D [[4:0] 5:0] +V_3 VID Multiplexer Lo Smart Driver Rcs Co VID Regulator Controller +V_VID Revision 7, December 2002 1 www.semtech.com