SEMTECH SC1474

SC1474 ® Portable Pentium Dual Phase Power Supply Controller POWER MANAGEMENT Description Features The SC1474 PowerStep III™ IC is a single chip high-per- ‹ IMVP3 compliant single chip solution formance Hysteretic PWM controller. With dual integrated ‹ High speed Dual phase hysteretic controller Smart™ Drivers, it powers advanced Pentium® 4 pro- ‹ VID programmable output cessors. The SC1474 features extended Intel Mobile Volt- ‹ Dual integrated 2A/4A drivers age Positioning (IMVP) to increase battery life by reduc- ‹ Integrated VID regulator controller ing the voltage at the processor when it is heavily loaded. ‹ Automatic performance/battery mode detection It directly supports Intel’s SpeedStep™ requirements for ‹ Dynamic phase current matching even longer battery life. The SC1474 automatically de- ‹ Under-voltage lock out on all Vcc inputs tects performance and battery mode VIDs. In addition, it ‹ Over-voltage protection on CORE integrates direct “deeper sleep” mode support. All op- ‹ Current Limit protection on CORE erating modes incorporate automatic “power-save” to prevent negative current flow in the low-side FET during ‹ Thermal protection light loading conditions, saving even more power. ‹ Programmable soft-start ‹ Powergood flag with blanking during VID changes A 5-bit DAC, accurate to 0.85%, sets the output voltage ‹ Automatic powersave at light load reference, and implements the 0.600V to 1.750V range ‹ TSSOP-38 package required by the processor. The hysteretic converter uses ‹ Industrial temperature range a comparator without an error amplifier, and so provides the fastest possible transient response, while avoiding Applications the stability issues inherent to classical PWM controllers. The SC1474 incorporates a controller for V_VID and au- ‹ Advanced Intel microprocessors tomatically provides the proper sequencing. 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 current limit pulses. It comes in a space- saving TSSOP-38 package. Typical Application Circuit +V_ +V_5 5 +V +V_ _I IN N Lo Lo Rc Rcs s +V +VC CO OR RE E Sm Sma ar rtt Dr Driiv ve er r Po Pow we er r Ex Extte en nd de ed d 0 0. .60 600V 0V- -1 1. .7 75 5V V U Up p to to 4 40 0A A Co Con nt tr ro oll IM IMV VP P Co Con nttr ro olllle er r Logi Logic c Si Sig gn na alls s SC SC1 14 47 74 4 Du Dua all P Ph ha as se e Ex Ext te ende nded d I IM MVP VP C CO ONT NTRO ROL LL LE ER R Lo Lo Rc Rcs s Sm Sma ar rtt VI VID D Dr Driiv ve er r VI VID D [ [4 4: :0 0] ] Mu Mullt tiip ple lex xe er r Co Co +V_ +V_3 3 VI VID D R Regu egulla atto or r Co Con nttr ro olllle er r +V_ +V_V VIID D Revision 6, December 2002 1 www.semtech.com