RT6254BHGJ8F Richtek

RT6254A/B TM 4A, 18V, 500kHz, ACOT Step-Down Converter General Description Features 4.5V to 18V Input Voltage Range The RT6254A/B is a high-efficiency, monolithic 4A Output Current synchronous step-down DC-DC converter that can deliver Constant-on-Time Mode to Enables Fast Transient up to 4A output current from a 4.5V to 18V input supply. Response The RT6254A/B adopts ACOT architecture to allow the Low Output Ripple and Allows Ceramic Output transient response to be improved and keep in constant Capacitor frequency. Cycle-by-cycle current limit provides protection 500kHz Switching Frequency against shorted outputs and soft-start eliminates input High Efficient Internal Power MOSFET Switch current surge during start-up. Fault conditions also include Optimized for Lower Duty Cycle Applications output under voltage protection and thermal shutdown. Integrated 48m/25m MOSFETs Adjustable Output Voltage from 0.6V to 5V Ordering Information Internal Soft-Start (1.5ms typ.) RT6254A/B Built-In UVP/OTP Package Type Power Good Indicator (90%) J6F : TSOT-23-6 (FC) J8F : TSOT-23-8 (FC) Input Under Voltage Lockout TSOT23-6 (FC) and TSOT23-8 (FC) Packages Lead Plating System G : Green (Halogen Free and Pb Free) Applications UVP Option H : Hiccup Set Top Box PSM/PWM Portable TV A : PSM/PWM Access Point Router B : Force-PWM DSL Modem Note : LCD TV 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 RT6254A/B V VIN BOOT IN C IN C BOOT L V EN LX OUT Enable C OUT R PGOOD C R1 FF R T PGOOD* FB AGND R2 GND * : PGOOD pin is for TSOT23-8 (FC) package. Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS6254A/B-01 October 2016 www.richtek.com 1RT6254A/B Pin Configuration (TOP VIEW) BOOT LX VIN 6 5 4 8 7 6 5 23 2 34 FB EN GND TSOT-23-6 (FC) TSOT-23-8 (FC) Marking Information RT6254AHGJ6F RT6254AHGJ8F 2D= : Product Code 1J= : Product Code 2D=DNN 1J=DNN DNN : Date Code DNN : Date Code RT6254BHGJ6F RT6254BHGJ8F 2C= : Product Code 1H= : Product Code 2C=DNN 1H=DNN DNN : Date Code DNN : Date Code Functional Pin Description Pin No. Pin Name Pin Function TSOT-23-6 (FC) TSOT-23-8 (FC) Feedback voltage input. This pin is used to set the desired 1 1 FB output voltage via an external resistive divider. -- 3 AGND Analog ground. This is the signal ground reference for the IC. Enable control input. Connecting this pin to logic high can 2 2 EN enable the device and connecting this pin to GND can disable the device. 3 4 GND System ground. This is the power return for the IC. 4 5 VIN Power input. Supplies the power switches of the device. Switch node. LX is the switching node that supplies power to the 5 6 LX output and connect the output LC filter from LX to the output load. Bootstrap supply for high-side gate driver. Connect a 0.1F 6 7 BOOT ceramic capacitor from LX to BOOT to power the high-side switch. Power good indicator. Open-drain output when the output -- 8 PGOOD voltage is within 90% to 120% of regulation point. Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS6254A/B-01 October 2016 2 PGOOD FB EN BOOT AGND LX GND VIN