SC453 Datasheet | SEMTECH

Description The SC453 IC is a single chip high-performance Hysteretic PWM controller. With its integrated Smart Driver™, it powers advanced graphics and core processors. It provides sleep mode and boot voltage support. Automatic "powersave" 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 parator 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. The SC453 operates from 5VDC and also Features softstart, an open-drain PWRGD signal with power good blanking, and an enable input. Programmable current limiting shuts down the SC453 after 32 current limit pulses. Features High Speed Hysteretic Controller Single Phase Operation Selectable Analog or VID Controlled Sleep Setting 6 Bit VID programmable Output Integrated Drivers with Soft-High Side Turn-On Programmable Soft-Start Programmable Boot Voltage Programmable Sleep Voltage with Sleep Mode Under-Voltage Lockout on VCCA Over-voltage Protection on CORE Current Limit Protection on CORE Thermal Protection Power Good Flag with Blanking During VCORE Changes Automatic Power Save at Light Load TSSOP-28 Package .. Applications Low Power Notebook and Laptop puters Embedded Applications Power Step IV™ and Smart Driver™ are trademarks of Semtech Corporation. Typical Application Circuit V5 VCCA VCORE 0.700V-1.708V Smart Driver PWM Controller SC453 Single Phase Power Supply VID (5:0) VID Logic and DAC August 25, 2006 .semtech. .. R1 R2 0 2 1 C6 1u F...