RT6234A/B TM 3A, 18V, 500kHz, ACOT Step-Down Converter General Description Features Integrated 130m / 70m MOSFETs The RT6234A/B is a high-efficiency, monolithic 4.5V to 18V Supply Voltage Range synchronous step-down DC/DC converter that can deliver 500kHz Switching Frequency up to 3A output current from a 4.5V to 18V input supply. ACOT Control The RT6234A/B adopts ACOT architecture to allow the 0.8V 2% Voltage Reference transient response to be improved and keep in constant Output Adjustable from 0.8V to 6.5V frequency. Cycle-by-cycle current limit provides protection Monotonic Start-Up into Pre-Biased Outputs against shorted outputs and soft-start eliminates input current surge during start-up. Fault conditions also include Applications output under voltage protection and thermal shutdown. Set Top Box Portable TV Ordering Information Access Point Router RT6234A/B DSL Modem Package Type LCD TV QW : WDFN-8L 2x3 (W-Type) Lead Plating System Pin Configurations G : Green (Halogen Free and Pb Free) (TOP VIEW) UVP Option H : Hiccup 1 8 BOOT SS 2 7 GND PGOOD A : PSM Mode SW 3 6 EN B : PWM Mode 9 VIN 4 5 FB Note : Richtek products are : WDFN-8L 2x3 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 RT6234A/B V VIN BOOT IN C BOOT C L IN V SW OUT Enable EN R1 C C FF OUT R PGOOD V PGOOD FB PGOOD R2 SS GND C SS Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS6234A/B-00 January 2016 www.richtek.com 1 GNDRT6234A/B Marking Information RT6234AHGQW RT6234BHGQW 11 : Product Code 10 : Product Code W : Date Code W : Date Code 11W 10W Function Pin Description Pin No. Pin Name Pin Function Bootstrap, Supply for High-Side Gate Driver. Connect a 0.1F or greater 1 BOOT ceramic capacitor between the BOOT pin and SW pin to power the high-side switch. System Ground. Provides the ground return path for the control circuitry and 2, GND low-side power MOSFET. The exposed pad must be soldered to a large PCB 9 (Exposed Pad) and connected to GND for maximum power dissipation. Switch Node. SW is the switching node that supplies power to the output and 3 SW connect the output LC filter from SW pin to the output load. 4 VIN Power Input. Supplies the power switches of the device. Feedback Voltage Input. This pin is used to set the desired output voltage via 5 FB an external resistive divider. Enable Control Input. Floating this pin or connecting this pin to ground can 6 EN disable the device and connecting this pin to logic high can enable the device. Power Good Indicator. This pin is an open-drain logic output that is pulled to 7 PGOOD ground when the output voltage is lower or higher than its specified threshold under the conditions of OTP, EN shutdown, or during soft-start. Soft-Start Control Input. Connect a capacitor between the SS pin and ground to 8 SS set the soft-start period. Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS6234A/B-00 January 2016 2