SC473MLTRT

Single-Phase Single Chip Graphics Core Power Supply POWER MANAGEMENT Description The SC473 is a single-phase chip, high-performance PWM controller designed to power advanced graphic cores. Onchip support is provided that includes slew-rate controlled VID transitions. The SC473 implements hysteretic control technology which provides the fastest possible transient response while avoiding the stability issues inherent to classical PWM controllers. Eliminating the sense resistors reduces costs and PCB area, plus increases system efficiency. Integrated SmartDriver™ technology initially turns on the high-side driver with ‘soft’ drive to reduce ringing, EMI, and capacitive turn-on of the low side MOSFET, while also increasing overall efficiency. Hysteretic operation adaptively reduces the SC473 switching frequency at light loads. Combined with an automatic “powersave” mode which prevents negative current flow in the low-side FET, system efficiency is significantly enhanced during light loading conditions. A 5-bit DAC, accurate to 0.85%, sets the output voltage reference, and implements the voltage range required by the processor. The DAC slew rate is externally programmed to minimize transient currents and audible noise. True differential remote sensing provides accurate point-of-load regulation at the processor die. Other features include programmable soft-start, an open-drain PWRGD output, dual-level over-voltage and programmable over-current protection. The SC473 is available in a space-saving 4x4mm, 24-pin MLP package. SC473 Features Single-Phase Solution with Integrated Drivers Hysteretic Control for Fast Transient Response SmartDriver™ for reduced EMI True Differential Remote (die) Sensing VID Programmed Voltage Delayed Power Good Signal with Blanking Programmable Soft-Start and DAC Slew Control Programmable OCP Threshold Supports all Ceramic Decoupling Solutions 24-Pin MLP (4x4) Lead-Free Package RoHS and WEEE compliant Applications High Performance Graphics Embedded Applications Updated - Aug 17, 2006 1 www.semtech.com 9 8 7 6 5 R11 1 0 C5 1UF 9 8 7 6 5 2 9 8 7 6 5 1 TG +VGFX 1 L1 0.33UH + 3 2 1 PMON C87 1 1 2 2 C85 R16 1 4 2 1 16.2K 22NF Q2 D D Q3 CR2 MBRS140L R29 C64 C88 330UF + 330UF 330UF 1 2 3 2 1 2 3 2 1 PGD C6 1NF *10K 2 PMON 2 BST TG DRN BG V5 PMON 24 23 22 21 20 19 GND CLSET VREF AGND ERROUT FBSS HYS 25 1 CLSET 7 VREF 8 9 E_OUT 10 11 12 2 C63 1 10NF 1 C66 C89 *100PF C13 *100PF 1 1 2 C14 *100PF R22 500K 2 E-RC 1 2 2 2 2 2 VREF 100PF © 2006 Semtech Corp. +VDC +V5S +V5R Notes: 1 1 1 1 1 1 1) '*' in value = NO_POP 1 1 C86 C4 2 1UF 2 4 2 25V C1 10UF 2 2 25V 25V C2 10UF 10UF 2 2 25V 25V C7 10UF 10UF 2 25V C3 C12 10UF *C10 *1uF CR1 MBR0530 1 Q1 D +V3.3S 2 BST R2 1 2 1.15V @ 30A 5 1 3 1 4 2 6 C90 + C91 + 330UF POWER MANAGEMENT Typical Application Circuit SC473 10K 2 PGD DRN BG 1 4 2 1 2 1 1 C24 C16 *1NF 2 2 10uF 10uF EN 2 R31 499 R13 10K R32 16.2K +VGFX Note: All Grounds Tied together at output Caps. R23 VID4 VID3 VID2 VID1 VID0 PGD EN RAMP CS+ CSFB+ VID4 VID3 VID2 VID1 VID0 1 2 3 4 5 6 VID4 VID3 VID2 VID1 VID0 HYS SC473 U1 1 0 R34 499 18 17 16 RAMP 15 14 13 2 1 C65 100PF SS R102 10 1 C84 2 2 100PF R17 130K 1 1 FB+ FBR103 10 C8 1NF R19 *8k 1 R18 130K To Regulation Point 2 1 C9 *100PF R20 90K C11 1 2 2 *560PF VREF SC473 www.semtech.com SC473 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Supply Voltage (V5) Condition Min -0.3 Max 6.5 30 34 6 25 29 BST, +0.3 V5, +0.3 VCCA +0.3 28 Units V V V V V V V V V o Static BST to PGND BST to DRN DRN to PGND TG to PGND BG to PGND All Other Pins to PGND Thermal Resistance Junction to Ambient JESD51 Standard Method* Operating Junction Temperature Range Storage Temperature Range Peak IR Reflow (10-40sec) θJA TJ TSTG TIRreflow Static Transient