SC453TSTRT Semtech

SC453 Portable, VID Programmed Single Phase Power Supply Controller POWER MANAGEMENT Description FFeeaturatureses The SC453 IC is a single chip high-performance Hysteretic High Speed Hysteretic Controller PWM controller. With its integrated SmartDrive it pow- Single Phase Operation ers advanced graphics and core processors. It provides Selectable Analog or VID Controlled Sleep Setting sleep mode and boot voltage support. Automatic power- 6 Bit VID programmable Output save is present to prevent negative current flow in the low- Integrated Drivers with SmartDrive side FET during light loading conditions saving even more Programmable Soft-Start power. The high side driver initially turns on with a weak Programmable Boot Voltage drive to reduce ringing, EMI, and capacitive turn-on of the Programmable Sleep Voltage with Sleep Mode low side. Under-Voltage Lockout on V and V CCA 5 Over-voltage Protection on V CORE A 6-bit DAC (accurate to 0.85%) sets the output voltage Current Limit Protection on V CORE reference and implements the 0.700V to 1.708V range Thermal Protection required by the processor. The hysteretic converter uses Power Good Flag with Blanking During a comparator without an error amplifier to provide fast V Changes CORE transient response while avoiding the stability issues in- Automatic Power Save at Light Load herent to classical PWM controllers. The DAC is externally Package Types TSSOP-28, MLPQ-32 slew rate limited to minimize transient currents and au- dible noise. The SC453 operates from a 5V supply and also features soft-start, an open-drain power good signal with V tran- CORE Applications sition blanking, and an enable input. Programmable cur- Low Power Notebook and Laptop Computers rent limiting shuts down the SC453 after 32 current limit Embedded Applications pulses. PowerStep IV and Smart Driver are trademarks of Semtech Corporation. Typical Application Circuit VIN V 5 V CCA VCORE 0.700V 1.708V + Smart Driver SC453 Single Phase Power Supply PWM Controller VID Logic VID (5:0) and DAC 1 www.semtech.com June 22, 2009SC453 POWER MANAGEMENT Reference Design 2009 Semtech Corp. 2 www.semtech.com 5V C1 VIN R1 D1 1uF 10 R2 0 MBR0530 BST L C6 C2 C3 C4 C5 C7 C8 EN 1uF 10uF 10uF 10uF 10uF no pop no pop DRN 1 28 DRN V5 Q1 Q2 U1 IRF7821 IRF7821 TG 2 27 BG TG BG 4 4 BST 3 26 BST PGND SC453 C9 SLP SLP 4 25 EN 1uF SLP EN PG R6 681 SLPV 5 24 CL SLPV CL C10 BOOTV CMP 6 23 BOOTV CMP R7 1K +VCORE 1nF PG CLRF 7 22 PG CLRF R8 681 CSH R3 R4 R5 5 L1 4 HYS 8 21 VCCA 12 HYS VCCA R9 C12 3 6 C14 C13 0.001 0.6uH 54.9K 33.2K 36.5K C11 C15 C16 VID5 R10 9 20 150pF 4.7uF + + 100pF 150pF VID5 REFIN VID5 no pop 330uF 330uF VID4 10 19 VID4 VID4 GND C18 C17 + + VID3 11 18 DAC VID3 DAC VID3 330uF 330uF R12 D D VID2 CORE 12 17 VID2 CORE +VCORE VID2 332 VID1 13 16 4 4 D2 VID1 PG DEL VID1 R11 MBRS140L VID0 14 15 SS C23 C22 R13 Q3 Q4 VID0 VID0 SS 0 IRF7832 no pop IRF7832 C22 1nF 330pF PG DEL 15nF PG DEL 8 3 7 2 6 1 5 8 3 7 8 2 6 3 7 1 5 2 6 1 5 8 3 7 2 6 1 5