SEMTECH SC450

SC450 Portable IMVP-IV™ and IMVP4+™ Dual Phase Power Supply Controller POWER MANAGEMENT Description Features ‹ IMVP-IV™ and IMVP4+™ compliant single chip The SC450 PowerStep IV™ IC is a single chip high-per- formance Hysteretic PWM controller. With its integrated solution SmartDriver™, it powers advanced IMVP-IV™ and ‹ On chip CLK_ENABLE# and IMVP4_PWRGD outputs IMVP4+™ processors. The SC450 features extended Intel ‹ Backward compatible with SC1476 Mobile Voltage Positioning (IMVP™) to increase battery ‹ High speed hysteretic controller life by reducing the voltage at the processor when it is ‹ 6 bit VID programmable output heavily loaded. It directly supports Intel’s SpeedStep® ‹ Integrated drivers with soft high side turn-on processors for even longer battery life. The SC450 fully ‹ Programmable softstart supports the Intel® Geyserville-III core voltage specifi- ‹ Programmable boot voltage cation. It provides direct “deeper sleep” mode and boot ‹ Programmable DeeperSleep voltage voltage support. Automatic “power-save” is present to ‹ Dynamic phase current matching prevent negative current flow in the low-side FET during ‹ Under-voltage lockout on VccA light loading conditions, saving even more power. The high ‹ Over-voltage protection on CORE side driver initially turns on with a weak drive to reduce ringing, EMI, and capacitive turn-on of the low side. ‹ Current Limit protection on CORE ‹ Thermal protection A 6-bit DAC, accurate to 0.85%, sets the output voltage ‹ Powergood flag with blanking during VID or reference, and implements the 0.700V to 1.708V range DeeperSleep mode changes required by the processor. The hysteretic converter uses ‹ Automatic powersave at light load a comparator without an error amplifier, and therefore ‹ Slew rate limited DAC provides the fastest possible transient response, while ‹ TSSOP-38 package avoiding the stability issues inherent to classical PWM controllers. The DAC is externally slew rate limited to mini- Applications mize transient currents and audible noise. ‹ Notebook and Laptop computers The SC450 operates from 3.3V and 5V. It also features ‹ Embedded applications soft-start, an open-drain PWRGD signal with power-good blanking, and an enable input. Programmable current PowerStep IV™ and SmartDriver™ are trademarks of Semtech Corporation. limiting shuts down the SC450 after 32 current limit pulses. In addition, it comes in a space-saving TSSOP- Other trademarks or registered trademarks may be claimed 38 package. as the property of others. Typical Application Circuit +V +V__55 +V +V_I _INN Rc Rcss Sm Sm aarrtt Lo Lo ++VVCORE CORE Dr Driive ver r Po Powweerr Ex Extteennded ded 0. 0.600V 600V--11..75V 75V PW PW MM U U p p to to 4 40 0A A CCont ontrrooll IIMV MVPP Logi Logicc Co Connttro rol lller er Si Signa gnallss SC1 SC1447744 DD ual ual P P hase hase EExxtteende nded d IIMV MVPP CONT CONTRO ROLLER LLER Lo Lo Rc Rcss Sm Sm aarrtt VI VIDD Dr Driive ver r VID[5:0] VID[5:0] VID[5:0] VID[5:0] VID[5:0] VI VID D [4 [4: :0 0] ] Mu Mullttiipl plex exeerr Co Co +V +V__33 VI VID D RRegu egullat ator or Co Connttro rol lller er +V +V__VVIIDD Revision: May 21, 2004 1 www.semtech.com