RT8079A 2.95V to 6V Input, 3A Output, 2MHz, Synchronous Step-Down Converter General Description Features Integrated 45m MOSFETs The RT8079A is a high efficiency step-down converter and Input Range : 2.95V to 6V capable of delivering 3A output current over a wide input Adjustable PWM Frequency : 300kHz to 2MHz voltage range from 2.95V to 6V. Output Current : 3A The RT8079A provides accurate regulation for a variety of 95% Efficiency loads with 3% accuracy. For reducing inductor size, it Adjustable Soft-Start provides up to 2MHz switching frequency. The efficiency Power Good Indicator is maximized through the integrated 45m MOSFETs Enable Control and 550A typical supply current. Under Voltage Lockout Under voltage lockout voltage of the RT8079A is 2.7V, Current Limit and it also provides external setting by a resistor network Thermal Shutdown on the enable pin. 16-Lead WQFN Package RoHS Compliant and Halogen Free The RT8079A provides protections such as inductor current limit under voltage lockout and thermal shutdown. The over temperature threshold is 145C. Applications Low-Voltage, High-Density Power Systems The RT8079A is available in WQFN-16L 3x3 package. Distributed Power Systems Point-of-Load Conversions Ordering Information RT8079A Package Type Marking Information QW : WQFN-16L 3x3 (W-Type) 1U= : Product Code Lead Plating System YMDNN : Date Code 1U=YM G : Green (Halogen Free and Pb Free) DNN 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. Simplified Application Circuit RT8079A V VIN SW V IN OUT EN BOOT PGOOD FB COMP SS/TR GND RT/SYNC AGND Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS8079A-02 May 2014 www.richtek.com 1RT8079A Pin Configurations (TOP VIEW) 16 15 14 13 1 12 VIN SW VIN 2 11 SW GND 3 10 GND SW 17 4 9 GND SS/TR 5 6 7 8 WQFN-16L 3x3 Functional Pin Description Pin No. Pin Name Pin Function 1, 2, 16 VIN Power Input. 3, 4, Power Ground. The exposed pad must be soldered to a large PCB and GND 17 (Exposed Pad) connected to GND for maximum power dissipation. 5 AGND Analog Ground. 6 FB Feedback Input. 7 COMP Compensation Node for Converter Stability. 8 RT/SYNC Frequency Setting and External Synchronous. Clock input. 9 SS/TR Soft-Start and Tracking. 10 to 12 SW Switch Node. Connect this pin to external L-C filter. Bootstrap Supply for High Side Gate Driver. Connect a capacitor between the 13 BOOT BOOT and SW pin. 14 PGOOD Output of Power Good Indicator. Chip Enable. Externally pulled high to enable and pulled low to disable this 15 EN chip. It is internally pulled up to high when the pin is floating. Function Block Diagram VIN Internal pull up Over Temperature current Protection UVLO Enable Comparator EN Shutdown Current EN Threshold Control Sense BOOT RT/SYNC Oscillator Control Driver SW Slope Logic Compensation PWM Comparator SS/TR Soft-Start GND V REF Error Amplifier FB PGOOD Threshold PGOOD Comparator PGOOD COMP AGND GND Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS8079A-02 May 2014 2 AGND VIN FB EN COMP PGOOD RT/SYNC BOOT