RT7255CGV8 Richtek

RT7255 TM 1.5A, 18V, 500kHz ACOT Synchronous Step-down Converter Features General Description 4.3V to 18V Input Voltage Range The RT7255 is a synchronous step-down converter Adjustable Soft-Start Time TM with Advanced Constant On-Time (ACOT ) mode PGOOD Function TM control. The ACOT provides a very fast transient 1.5A Output Current response with few external components. The low Advanced Constant On-Time Control impedance internal MOSFET supports high efficiency Fast Transient Response operation with wide input voltage range from 4.3V to Support All Ceramic Capacitors 18V. The proprietary circuit of the RT7255 supports all Up to 95% Efficiency ceramic capacitors. 500kHz Switching Frequency The output voltage can be adjusted between 0.6V and Adjustable Output Voltage from 0.6V to 8V 8V. Cycle-by-Cycle Current Limit Input Under-Voltage Lockout Ordering Information Hiccup Mode Under-Voltage Protection RT7255 Thermal Shutdown Package Type Applications V8 : SOT-23-8 Industrial and Commercial Low Power Systems Lead Plating System G : Green (Halogen Free and Pb Free) Computer Peripherals A : Hiccup + PSM LCD Monitors and TVs B : Non-UVP + PSM Green Electronics/Appliances C : Hiccup + PWM Point of Load Regulation for High-Performance D : Non-UVP + PWM DSPs, FPGAs, and ASICs Note : Richtek products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit L RT7255 V OUT V SW IN VIN C C BOOT IN BOOT R1 C C FF OUT R PG 5V PGOOD FB Enable EN R2 SS GND C SS Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS7255-00 June 2015 www.richtek.com 1 RT7255 Pin Configurations Marking Information RT7255AGV8 (TOP VIEW) 0B= : Product Code 0B=DNN DNN : Date Code RT7255BGV8 8 7 6 5 0A= : Product Code 0A=DNN DNN : Date Code 2 3 4 RT7255CGV8 09= : Product Code 09=DNN DNN : Date Code SOT-23-8 RT7255DGV8 06= : Product Code 06=DNN DNN : Date Code Functional Pin Description Pin No. Pin Name Pin Function Bootstrap Supply for High-Side Gate Driver. Connect a 1F ceramic 1 BOOT capacitor between the BOOT and SW pins. 2 GND Power Ground. Soft-Start Time Setting. Connect a capacitor from SS to GND to set the 3 SS soft-start period. Feedback Voltage Input. The pin is used to set the output voltage of the 4 FB converter via a resistive divider. The converter regulates V to 0.6V. FB 5 PGOOD Power Good Indicator Output. Enable Control Input. Connect EN to a logic-high voltage to enable the IC or 6 EN to a logic-low voltage to disable. Do not leave this high impedance input unconnected. Power Input. The input voltage range is from 4.3V to 18V. Must bypass with 7 VIN a suitable large ceramic capacitor at this pin. 8 SW Switch Node. Connect to external L-C filter. Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS7255-00 June 2015 2 BOOT SW VIN GND SS EN FB PGOOD