RT6154A/B High Efficiency Single Inductor Buck-Boost Converter General Description Features zz z zz Operates from a Single Li-ion Cell : 1.8V to 5.5V The RT6154A/B is a high efficiency single inductor Buck- zz z zz Adjustable Output Voltage : 1.8V to 5.5V Boost Converter which can operate with wide input voltage zz z zz 3A Maximum Load Capability for V > 3.6V, IN such as battery which is higher or lower than the output V = 3.3V OUT voltage and it can supply the load current up to 4A. The zz z zz Power Save Mode (PSM) for Improving Low Output maximum peak current in the switches is limited to a Power Efficiency typical value of 5A. zz z zz Fixed Frequency Operation at 2.4MHz and The RT6154A/B feedback loop is internally compensated Synchronization Possible from 2.2MHz to 2.6MHz for both Buck and Boost operation and it provides seamless zz z zz Up to 96% Efficiency transition between Buck and Boost modes and optimal zz z zz Input Current Limit transient response. The RT6154A/B operates at 2.4MHz zz z zz Internal Compensation typical switching frequency in full synchronous operation. zz z zz RoHS Compliant and Halogen Free The RT6154A/B operates in Pulse Skipped Modulation (PSM) mode for increasing efficiency during low power Applications RF transmission modes. The Power Save Mode can be z Cellular Phones disabled, forcing the RT6154A/B to operate at a fixed z Portable Hard Disk Drives switching frequency operation at 2.4MHz. The RT6154A/ z PDAs B can also be synchronized with external frequency from 2.2MHz to 2.6MHz. The RT6154A output voltage is Pin Configurations programmable using an external resistor divider, and the (TOP VIEW) RT6154B is fixed internally to 3.3V. 1 14 PGOOD VINA 13 GND 2 PS/SYNC 12 FB 3 EN 4 11 VOUT VIN PGND VOUT 5 10 VIN 6 9 LX2 LX1 15 7 8 LX2 LX1 WDFN-14AL 4x3 Simplified Application Circuit LX1 LX2 RT6154A V VOUT IN VIN V OUT VINA FB Power Good Enable EN PGOOD Output PS/SYNC GND PGND Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS6154A/B-01 May 2014 www.richtek.com 1RT6154A/B Ordering Information Marking Information RT6154A/B RT6154AGQW Package Type 0E= : Product Code QW : WDFN-14AL 4x3 (W-Type) YMDNN : Date Code 0E=YM Lead Plating System DNN G : Green (Halogen Free and Pb Free) RT6154A Adjustable Output Voltage RT6154B Fixed 3.3V Output Voltage RT6154BGQW Note : 0D= : Product Code Richtek products are : YMDNN : Date Code 0D=YM RoHS compliant and compatible with the current require- DNN ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Functional Pin Description Pin No. Pin Name Pin Function 1 VINA Supply Voltage Input. 2 GND Analog Ground. Voltage Feedback of Adjustable Versions, must be connected to VOUT on 3 FB fixed output voltage versions. 4, 5 VOUT Buck-Boost Converter Output. 6, 7 LX2 Second Switch Node. 8, 9 LX1 First Switch Node. 10, 11 VIN Power Input. 12 EN Enable Control Input (1 Enabled, 0 Disabled). Must not be left open. Enable/Disable Control Input for Power Save Mode (1 disabled, 0 enabled, 13 PS/SYNC clock signal for synchronization). Must not be left open. 14 PGOOD Power Good Indicator Output. (1 good, 0 failure open drain). 15 Power Ground. The exposed pad must be soldered to a large PCB and PGND (Exposed Pad) connected to PGND for maximum power dissipation. Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS6154A/B-01 May 2014 2