RT8204L Single Synchronous Buck Controller General Description Features zz z zz PWM Controller The RT8204L PWM controller provides high efficiency, Ultra High Efficiency excellent transient response, and high DC output accuracy Resistor Programmable Current Limit by Low Side needed for stepping down high voltage batteries to R Sense (Lossless Limit) DS(ON) generate low voltage CPU core, I/O, and chipset RAM 4700ppm/C R Current Sensing DS(ON) supplies in notebook computers. Quick Load Step Response within 100ns The constant-on-time PWM control scheme handles wide 1% V Accuracy Over Line and Load FB input/output voltage ratios with ease and provides 100ns Adjustable 0.75V to 3.3V Output Range instant-on response to load transients while maintaining 4.5V to 26V Battery Input Range a relatively constant switching frequency. Resistor Programmable Frequency The RT8204L achieves high efficiency at a reduced cost Integrated Bootstrap Switch by eliminating the current sense resistor found in Over/Under Voltage Protection traditional current mode PWMs. Efficiency is further Voltage Ramp Soft-Start enhanced by its ability to drive very large synchronous Power Good Indicator rectifier MOSFETs. The buck conversion allows this device zz z zz LDO Controller to directly step down high voltage batteries for the highest 1.5% accuracy Over Line and Load possible efficiency. The RT8204L is intended for CPU core, Independent Enable and Power Good Indicator chipset, DRAM, or other low voltage supplies as low as Drive N-MOSFETs within Rail to Rail Controller 0.75V. The RT8204L is available in a WQFN-16L 3x3 Voltage package. MLCC and POSCAP Stable zz z zz RoHS Compliant and Halogen Free A built in LDO controller can drive an external N-MOSFET to provide a second output voltage from PWM output or Applications other power source. The RT8204L can provide adjustable voltage down to 0.75V and maximum output voltage is z Notebook Computers dependen on the selected MOSFET. The internal 0.75V z CPU Core Supply reference voltage with 1.5% accuracy provides tight z Chipset/RAM Supply as Low as 0.75V regulation of the output voltage. Other features such as independent enable control, open drain power good Ordering Information RT8204L indicator, under voltage protection, and soft start make the RT8204L a system friendly power management solution Package Type QW : WQFN-16L 3x3 (W-Type) for various applications. Lead Plating System G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free) Note : Richtek products are : RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. DS8204L-04 April 2011 www.richtek.com 1V IN 4.5V to 26V R TON C4 RT8204L R4 TON BOOT V C3 OUT1 VDDP R5 1 UGATE Q L1 PHASE LGATE R6* C8 Q2 R ILIM OC R7 C5* C6* FB EN/DEM CCM/DEM C7* R8 E L N LDO Enable LPGOOD LDO PGOOD VOUT C14 V DDP Q3 LDRV V OUT2 R10 R9 R11 C11* C12 C13 C10 LFB R12 C9 : io * Opt nal RT8204L Marking Information Pin Configurations RT8204LGQW (TOP VIEW) J8= : Product Code YMDNN : Data Code J8=YM 16 15 14 13 DNN 1 12 VOUT UGATE 2 11 VDD PHASE GND FB 3 10 OC 17 4 9 PGOOD VDDP 5 6 7 8 RT8204LZQW J8 : Product Code YMDNN : Data Code J8 YM DNN WQFN-16L 3x3 Typical Application Circuit 16 13 9 12 11 2 8 10 4 3 15 14 5 1 7 17 (Exposed Pad) 6 www.richtek.com DS8204L-04 April 2011 2 V DDP 5V C1 R2 R1 VDD C2 PGOOD PGOOD R3 GND LPGOOD TON LFB EN/DEM LDRV LEN LGATE BOOT