RT2862 3A, 36V, Synchronous Step-Down Converter General Description Features 4.5V to 36V Input Voltage Range The RT2862 is a high efficiency, current-mode 3A Output Current synchronous step-down DC/DC converter that can deliver Internal N-MOSFETs up to 3A output current over a wide input voltage range Current Mode Control from 4.5V to 36V. The device integrates 105m high-side Frequency Operation : 300kHz to 1MHz and 80m low-side MOSFETs to achieve high conversion Adjustable Output Voltage from 0.8V to 30V efficiency. The current-mode control architecture supports High Efficiency Up to 95% fast transient response and simple external compensation. Stable with Low ESR Ceramic Output Capacitors A cycle-by-cycle current limit function provides protection Cycle-by-Cycle Current Limit against shorted output and an internal soft-start eliminates Input Under-Voltage Lockout input current surge during start-up. The RT2862 provides Output Under-Voltage Protection complete protection functions such as input under-voltage Thermal Shutdown lockout, output under-voltage protection, over-current protection and thermal shutdown. Applications The RT2862 is available in the thermal enhanced SOP-8 Point of Load Regulator in Distributed Power Systems (Exposed Pad) package. Digital Set Top Boxes Broadband Communications Ordering Information Vehicle Electronics RT2862 Automotive Audio, Navigation, and Information Systems Package Type Enterprise Datacom Platforms Point of Load (POL) SP: SOP-8 (Exposed Pad-Option 2) Industrial Grade General Purpose Point of Load Lead Plating System G : Green (Halogen Free and Pb Free) Marking Information Note : RT2862GSP : Product Number Richtek products are : RT2862 YMDNN : Date Code RoHS compliant and compatible with the current require- GSPYMDNN ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit V VIN BOOT IN C RT2862 C IN B L SW V OUT R1 RT FB C OUT R T R2 C C R C GND COMP Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS2862-00 July 2014 www.richtek.com 1RT2862 Pin Configurations (TOP VIEW) 8 SW VIN 2 7 BOOT RT GND 3 6 EN COMP 9 4 5 GND FB SOP-8 (Exposed Pad) Functional Pin Description Pin No. Pin Name Pin Function 1 SW Switch Node. Connect to external L-C filter. Bootstrap Supply for the High-Side MOSFET. Connect a 100nF or greater 2 BOOT capacitor between the BOOT and SW pins. Enable Control Input. A logic-high enables the converter a logic-low forces the 3 EN device into shutdown mode. 4, Ground. The exposed pad must be soldered to a large PCB and connected to GND 9 (Exposed Pad) GND for maximum thermal dissipation. Feedback Voltage Input. This pin is used to set the output voltage of the 5 FB converter to regulate to the desired value via an resistive divider. Compensation Node. COMP is used to compensate the regulation control loop. 6 COMP Connect a R-C network from the COMP to GND. In some cases, an additional capacitor from COMP to GND is required. Switching Frequency Setting. Connect an external resistor to set the switching 7 RT frequency from 300kHz to 1MHz. Power Input. The input voltage range is from 4.5V to 36V. Must bypass with a 8 VIN suitable large ceramic capacitor at this pin. Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS2862-00 July 2014 2