RT6201A/B TM 4A, 18V, 650kHz, ACOT Synchronous Step-Down Converter General Description Features TM ACOT Mode Enables Fast Transient Response The RT6201A/B is a synchronous step-down DC/DC TM 4.5V to 18V Input Voltage Range converter with Advanced Constant On-Time (ACOT ) 4A Output Current mode control. It achieves high power density to deliver up 50m Internal Low Side N-MOSFET to 4A output current from a 4.5V to 18V input supply. The TM Advanced Constant On-Time Control proprietary ACOT mode offers an optimal transient Support All Ceramic Capacitors response over a wide range of loads and all kinds of ceramic Up to 95% Efficiency capacitors, which allows the device to adopt very low ESR 650kHz Switching Frequency at all Load Current output capacitor for ensuring performance stabilization. In (RT6201B) addition, RT6201A/B keeps an excellent constant Discontinuous Operating Mode at Light Load switching frequency under line and load variation and the TM (RT6201A) integrated synchronous power switches with the ACOT Adjustable Output Voltage from 0.765V to 8V mode operation provides high efficiency in whole output Adjustable Soft-Start current load range. Cycle-by-cycle current limit provides Cycle-by-Cycle Current Limit an accurate protection by a valley detection of low side Input Under Voltage Lockout MOSFET and external soft-start setting eliminates input Thermal Shutdown current surge during startup. Protection functions include RoHS Compliant and Halogen Free thermal shutdown for RT6201A/B. The RT6201A/B are available in the SOP-8 (Exposed Pad) Applications package. Industrial and Commercial Low Power Systems Computer Peripherals Pin Configurations LCD Monitors and TVs (TOP VIEW) Green Electronics/Appliances 8 EN VIN Point of Load Regulation for High-Performance DSPs, 2 7 FB BOOT GND FPGAs, and ASICs 3 6 VREG5 SW 9 4 5 SS GND SOP-8 (Exposed Pad) Simplified Application Circuit RT6201A/B VIN V V IN SW OUT BOOT Enable EN FB VREG5 SS GND Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS6201A/B-00 December 2013 www.richtek.com 1RT6201A/B Ordering Information Marking Information RT6201A/B RT6201AHGSP RT6201AHGSP : Product Number Package Type RT6201AH YMDNN : Date Code SP : SOP-8 (Exposed Pad-Option 2) GSPYMDNN Lead Plating System G : Green (Halogen Free and Pb Free) UVP Trim Operation RT6201BHGSP H : Hiccup RT6201BHGSP : Product Number PSM/PWM Mode RT6201BH YMDNN : Date Code A : PSM Mode GSPYMDNN B : PWM Mode 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. Functional Pin Description Pin No. Pin Name Pin Function Enable Control Input. A logic-high enables the converter a logic-low forces the 1 EN IC into shutdown mode reducing the supply current to less than 10 A. Feedback Voltage Input. It is used to regulate the output of the converter to a set 2 FB value via an external resistive voltage divider. The feedback threshold voltage is 0.765V typically. Internal Regulator Output. Connect a 1F capacitor to GND to stabilize output 3 VREG5 voltage. Soft-Start Time Setting. Connect an external capacitor between this pin and GND to 4 SS set the soft- start time. 5, 9 Power Ground. The exposed pad must be soldered to a large PCB and GND (Exposed Pad) connected to GND for maximum power dissipation. 6 SW Switch Node. Connect this pin to an external L-C filter. Bootstrap Supply for High Side Gate Driver. Connect a 0.1 F capacitor between 7 BOOT the BOOT and SW pin. Power Input. The input voltage range is from 4.5V to 18V. Must bypass with a 8 VIN suitably large ( 10F x 2) ceramic capacitor. Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS6201A/B-00 December 2013 2