RT9296 Synchronous Boost Converter with LDO Controller General Description Features zz z zz True Load Disconnection During Shutdown The RT9296 is a synchronous boost converter, which is zz z zz Internal Synchronous Rectifier based on a fixed frequency pulse-width-modulation (PWM) zz z zz Up to 96% Efficiency controller using a synchronous rectifier to obtain maximum zz z zz Current Mode PWM Operation with Internal efficiency. The converter provides a power supply solution Compensation for products powered by a variety of batteries such as zz z zz Low Start-Up Voltage single cell, dual cell alkaline, NiMH and NiCd battery. At zz z zz Low Quiescent Current light load currents, the converter enters the power save zz z zz Internal Soft-Start Control mode to maintain a high efficiency over a wide load current zz z zz Linear Controller range. zz z zz Low EMI Converter (Anti-Ringing) The output voltage can be programmed by an external zz z zz Power Save Mode for Improved Efficiency at Light resistor divider, or be a fixed voltage. Moreover, the Load Current converter can be disabled to the minimize battery drain. zz z zz Over-Current Protection During shutdown, the load is completely disconnected zz z zz Short Circuit Protection from the battery. The maximum peak current in the boost zz z zz Over Temperature Protection switch is limited to 2A for current limit. zz z zz Over Voltage Protection For the RT9296, a low-EMI (anti-ringing) mode is zz z zz Small 10-Lead WDFN Package implemented (by trim option) to reduce ringing of the zz z zz RoHS Compliant and Halogen Free inductor phase pin when the converter enters the discontinuous conduction mode. Moreover, a linear Applications controller is built-in in the chip for linear regulator z All One-Cell, Two-Cell and Three-Cell Alkaline, NiCd, application. NiMH and Single-Cell Li Batteries z Hand-Held Devices Ordering Information z WLED Flash Light RT9296(- ) Package Type Pin Configurations QW : WDFN-10L 3x3 (W-Type) (TOP VIEW) Lead Plating System G : Green (Halogen Free and Pb Free) EN 1 10 PGND 9 VOUT 2 LX Boost VOUT 3 8 FB/NC PGOOD Default : Adjustable 4 7 FBL DRV 33 : 3.3V 5 11 6 GND VBAT 50 : 5.0V Note : WDFN-10L 3x3 Richtek products are : RoHS compliant and compatible with the current require- Marking Information ments of IPC/JEDEC J-STD-020. For marking information, contact our sales representative Suitable for use in SnPb or Pb-free soldering processes. directly or through a Richtek distributor located in your area. DS9296-01 April 2011 www.richtek.com 1 GNDRT9296 Typical Application Circuit L RT9296 4.7H 2 9 V LX VOUT V OUT BAT C IN C OUT 6 R1 10F VBAT 22F 4 Q1 DRV R4 8 V LDO PGOOD OUT R2 C LDO Chip Enable 1 EN 7 FBL 5, Exposed Pad (11) 10 GND PGND R3 Figure 1. Fixed Output Voltage Boost Converter with Linear Regulator L RT9296 4.7H 2 9 VOUT V V LX BAT OUT C IN C OUT 6 R1 10F VBAT 22F 3 R3 FB R5 8 R2 V PGOOD OUT 4 Q1 DRV Chip Enable 10 1 PGND EN WLED 7 5, Exposed Pad (11) FBL GND R4 Figure 2. Adjustable Output Voltage Boost Converter with WLED Driver Functional Pin Description Pin No. Pin Name Pin Function 1 EN Chip Enable (Active High). 2 VOUT Boost Output. 3 FB / NC Feedback Pin / No Internal Connection. 4 DRV Driver of Linear Controller. 5 GND Ground. 6 VBAT Battery Supply Input. 7 FBL Feedback Input Linear Controller. 8 PGOOD Power Good Indicator. 9 LX Switching Node. Connect this Pin to an inductor. 10 PGND Power Ground. Ground. The exposed pad must be soldered to a large PCB and connected to 11 (Exposed Pad) GND GND for maximum power dissipation. www.richtek.com DS9296-01 April 2011 2