SC1474 Datasheet | SEMTECH

escription The SC1474 Power Step III™ IC is a single chip high-performance Hysteretic PWM controller. With dual integrated Smart™ Drivers, it powers advanced Pentium® 4 processors. The SC1474 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’s Speed Step™ requirements for even longer battery life. The SC1474 automatically detects performance and battery mode VIDs. In addition, it integrates direct “deeper sleep” mode support. All operating modes incorporate automatic “power-save” to prevent negative current flow in the low-side FET during light loading conditions, saving even more power. Features IMVP3 pliant single chip solution High speed Dual phase hysteretic controller VID programmable output Dual integrated 2A/4A drivers Integrated VID regulator controller Automatic performance/battery mode detection Dynamic phase current matching Under-voltage lock out on all Vcc inputs Over-voltage protection on CORE Current Limit protection on CORE Thermal protection Programmable soft-start Powergood flag with blanking during VID changes Automatic powersave at light load TSSOP-38 package Industrial temperature range ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ A 5-bit DAC, accurate to 0.85%, sets the output voltage ‹ reference, and implements the 0.600V to 1.750V range ‹ required by the processor. The hysteretic converter uses ‹ a parator without an error amplifier, and so provides the fastest possible transient response, while avoiding the stability issues inherent to classical PWM controllers. The SC1474 incorporates a controller for V_VID and automatically provides the proper sequencing. Applications ‹ Advanced Intel microprocessors The SC1474 operates from +3.3Vdc Vcca and dual 5V DC drive inputs. It also Features soft-start, an open-drain PWRGD signal with power-good blanking, and an enable input. Programmable current limiting latches the SC1474 off after 32...