Reference Design Sample & Design Tools Buy RT7295C TM 3.5A, 18V, 500kHz ACOT Synchronous Step-Down Converter General Description Features zz z zz 4.3V to 18V Input Voltage Range The RT7295C is a synchronous step-down converter with TM zz z zz 3.5A Output Current Advanced Constant On-Time (ACOT ) mode control. The TM zz z zz Advanced Constant On-Time Control ACOT provides a very fast transient response with few zz z zz Fast Transient Response external components. The low impedance internal zz z zz Support All Ceramic Capacitors MOSFET supports high efficiency operation with wide input zz z zz Up to 95% Efficiency voltage range from 4.3V to 18V. The proprietary circuit of zz z zz 500kHz Switching Frequency the RT7295C enables to support all ceramic capacitors. zz z zz Adjustable Output Voltage from 0.6V to 8V The output voltage can be adjusted between 0.6V and 8V. zz z zz Cycle-by-Cycle Current Limit zz z zz Input Under-Voltage Lockout Ordering Information zz z zz Hiccup Mode Under-Voltage Protection RT7295C zz z zz Thermal Shutdown Package Type zz z zz RoHS Compliant and Halogen Free J6F : TSOT-23-6 (FC) Lead Plating System Applications G : Green (Halogen Free and Pb Free) z Industrial and Commercial Low Power Systems Note : z Computer Peripherals Richtek products are : z LCD Monitors and TVs RoHS compliant and compatible with the current require- z Green Electronics/Appliances ments of IPC/JEDEC J-STD-020. z Point of Load Regulation for High-Performance DSPs, Suitable for use in SnPb or Pb-free soldering processes. FPGAs, and ASICs Pin Configurations Marking Information (TOP VIEW) 05= : Product Code SW VIN EN 05=DNN DNN : Date Code 6 5 4 23 BOOTGND FB TSOT-23-6 (FC) Simplified Application Circuit RT7295C BOOT V VIN IN SW V OUT Enable EN FB GND Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS7295C-09 February 2018 www.richtek.com 1RT7295C Functional Pin Description Pin No. Pin Name Pin Function Bootstrap Supply for High-Side Gate Driver. Connect a 0.1 F ceramic capacitor 1 BOOT between the BOOT and SW pins. 2 GND Power Ground. Feedback Voltage Input. The pin is used to set the output voltage of the converter 3 FB via a resistive divider. The converter regulates V to 0.6V FB Enable Control Input. Connect EN to a logic-high voltage to enable the IC or to a 4 EN 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 a 5 VIN suitable large ceramic capacitor at this pin. 6 SW Switch Node. Connect to external L-C filter. Function Block Diagram BOOT VIN V IN Reg PVCC VIBIAS Min off V REF PVCC UGATE OC SW Driver Control LGATE UV & OV GND PVCC Ripple GND SW SW Gen. V IN + - EN On-Time SW - Comparator FB EN Operation The RT7295C is a synchronous step-down converter with UVLO Protection advanced constant on-time control mode. Using the ACOT To protect the chip from operating at insufficient supply control mode can reduce the output capacitance and fast voltage, the UVLO is needed. When the input voltage of transient response. It can minimize the component size VIN is lower than the UVLO falling threshold voltage, the without additional external compensation network. device will be lockout. Current Protection Thermal Shutdown The inductor current is monitored via the internal switches When the junction temperature exceeds the OTP cycle-by-cycle. Once the output voltage drops under UV threshold value, the IC will shut down the switching threshold, the RT7295C will enter hiccup mode. operation. Once the junction temperature cools down and is lower than the OTP lower threshold, the converter will autocratically resume switching. Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS7295C-09 February 2018 2