RT7263E 3A, 21V 500kHz Synchronous Step-Down Converter General Description Features zz z zz Wide Input Range : 4.5V to 21V The RT7263E is a synchronous step-down regulator with zz z zz Adjustable Output from 0.808V to 15V an internal power MOSFET. It achieves 3A of continuous zz z zz 3A Output Current output current over a wide input supply range with excellent zz z zz 120m/40m Internal Power MOSFET Switch load and line regulation. Current mode operation provides zz z zz Internal Compensation Minimizes External Parts fast transient response and eases loop stabilization. zz z zz 500kHz Fixed Switching Frequency Fault condition protection includes cycle-by-cycle current zz z zz Synchronized External Clock from 300kHz to 2MHz limiting and thermal shutdown. An adjustable soft-start zz z zz Adjustable Soft-Start reduces the stress on the input source at startup. zz z zz Cycle-by-Cycle Over Current Limit The RT7263E requires a minimal number of readily zz z zz Thermal Shutdown Protection available external components, providing a compact zz z zz Available in SOP-8 (Exposed Pad) and 14-Lead solution. WDFN Packages zz z zz RoHS Compliant and Halogen Free Ordering Information RT7263E Applications Package Type z Distributive Power Systems QW : WDFN-14L 4x3 (W-Type) SP : SOP-8 (Exposed Pad-Option 2) z Battery Charger Lead Plating System z DSL Modems Z : ECO (Ecological Element with z Pre-Regulator for Linear Regulators Halogen Free and Pb free) Note : 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 V VIN BOOT IN C RT7263E BOOT C IN L SW V Chip Enable OUT EN/SYNC R R1 T VCC FB C C C GND R2 OUT Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS7263E-00 November 2012 www.richtek.com 1RT7263E Marking Information Pin Configurations (TOP VIEW) RT7263EZQW 05 : Product Code 1 14 VIN AGND YMDNN : Date Code 13 05 YM SW 2 GND SW 3 12 GND DNN 4 11 VCC SW GND 5 10 SW SS 69 BOOT PGOOD 15 78 EN/SYNC FB WDFN-14L 4x3 RT7263EZSP RT7263EZSP : Product Number RT7263E YMDNN : Date Code VIN 8 GND ZSPYMDNN 2 7 SW VCC GND SW 3 6 FB 9 4 BOOT 5 EN/SYNC SOP-8 (Exposed Pad) Functional Pin Description Pin No. Pin Name Pin Function SOP-8 WDFN-14L 4x3 (Exposed Pad) Power Input. VIN supplies the power to the IC, as well as the step-down converter switches. Drive VIN with a 4.5V to 21V 1 1 VIN power source. Bypass VIN to GND with a suitably large capacitor to eliminate noise on the input to the IC. Switch Node. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output 2, 3, 4, 5 2, 3 SW load. Note that a capacitor is required from SW to BOOT to power the high side switch. Bootstrap for High Side Gate Driver. Connect a 100nF or greater 6 4 BOOT capacitor from SW to BOOT to power the high side switch driver. Enable or External Frequency Synchronization Input. For automatic start-up, connect the EN/SYNC pin to VIN with a 7 5 EN/SYNC 100k resistor. The switching frequency can be changed by an external clock applying to the SYNC pin. Feedback Input. FB senses the output voltage via an external 8 6 FB resistive voltage divider. The feedback reference voltage is 0.808V typically. Power Good Indicator is an Open Drain Output. The power good 9 -- PGOOD rising/falling threshold is 90%/70% of regulation output voltage. Soft-Start Control Input. Connect a capacitor from SS to GND to 10 -- SS set the soft-start period. Bias Supply. Decouple with 0.1F to 0.22F capacitor between 11 7 VCC this pin and GND. 12, 13, 15 8, Ground. The exposed pad must be soldered to a large PCB and GND (Exposed Pad) 9 (Exposed Pad) connected to GND for maximum power dissipation. Analog Ground. Connect this pin to the system ground in PCB 14 -- AGND layout. Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS7263E-00 November 2012 2
