RT2858B TM 3A, 18V, 650kHz ACOT Synchronous Step-Down Converter General Description Features TM zz z zz ACOT Control for Fast Transient, f Stability, and SW The RT2858B is a synchronous DC/DC step-down TM Robust Loop Stability with all-MLCC C OUT converter with Advanced Constant On-Time (ACOT ) zz z zz 4.5V to 18V Input Voltage Range mode control. It achieves high power density to deliver up zz z zz 3A Output Current to 3A output current from a 4.5V to 18V input supply. The TM zz z zz R 120m/////50m for High Efficiency Across I DSON OUT proprietary ACOT mode offers an optimal transient Range and Competitive Advantage for I > 1.5A OUT response over a wide range of loads and all kinds of ceramic zz z zz Advanced Constant On-Time Control capacitors, which allows the device to adopt very low ESR zz z zz Support All Ceramic Capacitors output capacitors for ensuring performance stabilization. zz z zz Up to 95% Efficiency In addition, the RT2858B keeps an excellent constant zz z zz 650kHz f Start-Up into Pre-Biased Load SW switching frequency under line and load variation and the TM Adjustable Soft-Start Internal Bootstrap integrated synchronous power switches with the ACOT zz z zz Adjustable Output Voltage from 0.765V to 8V mode operation provides high efficiency in whole output zz z zz Enable UVLO OCP (Cycle-by-Cycle) and OTP current load range. Cycle-by-cycle current limit provides (150C) an accurate protection by a valley detection of low-side zz z zz RoHS Compliant and Halogen Free MOSFET and external soft-start setting eliminates input current surge during startup. Protection functions also include output under voltage protection and thermal Applications shutdown. z Industrial and Commercial Low Power Systems z Computer Peripherals z LCD Monitors and TVs z Green Electronics/Appliances z Point of Load Regulation for High-Performance DSPs, FPGAs, and ASICs Simplified Application Circuit Load Transient Response V OUT RT2858B L1 (50mV/Div) VIN SW V V OUT IN C1 C2 C7 C6 C3 R1 BOOT Enable EN FB SS PVCC R2 V PVCC C5 C4 GND IOUT (1A/Div) V = 12V, V = 1.05V, I = 0A to 3A IN OUT OUT Time (100s/Div) Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS2858B-00 September 2013 www.richtek.com 1RT2858B Ordering Information Marking Information RT2858B RT2858BHGSP Package Type RT2858BHGSP : Product Number SP : SOP-8 (Exposed Pad-Option 2) RT2858BH YMDNN : Date Code GSPYMDNN Lead Plating System G : Green (Halogen Free and Pb Free) H : Hiccup Mode OVP and UVP RT2858BNGSP N : OVP and UVP disable RT2858BNGSP : Product Number Note : RT2858BN YMDNN : Date Code GSPYMDNN 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. Pin Configurations (TOP VIEW) 8 EN VIN 2 7 FB BOOT GND 3 6 PVCC SW 9 4 SS 5 GND SOP-8 (Exposed Pad) Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS2858B-00 September 2013 2