V IN L1 V VDD L2 GPIO RT2701 Dual-Phase PWM Controller for GPU Core Power Supply General Description Features zz z zz Dual-Phase PWM Controller The RT2701 is a dual-phase synchronous Buck PWM zz z zz Two Embedded MOSFET Drivers and Embedded controller with integrated drivers which are optimized for Switching Boot Diode high performance graphic microprocessor and computer zz z zz Dynamic Auto Phase Control with Adjustable applications. The IC integrates a PWM controller, two 12V Threshold MOSFET drivers with internal bootstrap diodes, as well TM zz z zz Cross-talk Jitter Suspend (CJS ) as output current monitoring and protection functions into zz z zz Remote GND Detection for High Accuracy the WQFN-24L 4x4 package. The RT2701 adopts DCR zz z zz Automatic Diode Emulation Mode/Or Ultrasonic and R current sensing. Over current protection is DS(ON) Mode at Light Load accomplished through continuous inductor DCR current zz z zz Lossless R Current Sensing for Current Balance DS(ON) sensing, while R current sensing is used for accurate DS(ON) zz z zz Lossless DCR Current Sensing for AVP & OCP channel current balance. Using both methods of current zz z zz Reference Voltage Output with 1% Accuracy sampling utilizes the best advantages of each technique. zz z zz External Reference Input with Soft-Start (RISS) The RT2701 also features an one-bit VID control operation zz z zz Embedded One-Bit VID Control in which the feedback voltage is regulated and tracks zz z zz Adjustable OCP Threshold external input reference voltage. Other features include zz z zz Adjustable Switching Frequency adjustable operating frequency, external compensation and zz z zz Reference Tracking UVP/OVP Protection enable/shutdown functions. zz z zz Shoot Through Protection and Short Pulse Free Technology Ordering Information zz z zz RoHS Compliant and Halogen Free RT2701 Package Type QW : WQFN-24L 4x4 (W-Type) Applications (Exposed Pad-Option 1) z Middle to High End GPU Core Power Lead Plating System z High End Desktop PC Memory Core Power G : Green (Halogen Free and Pb Free) z Low Voltage, High Current DC/DC Converter Note : z Voltage Regulator Modules 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 RT2701 VCC PHASE1 MOSFET VID PHASE2 MOSFET OCP PS PGND RMPSET Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS2701-00 May 2013 www.richtek.com 1RT2701 Pin Configurations Marking Information 03= : Product Code (TOP VIEW) YMDNN : Date Code 03=YM DNN 24 23 22 21 20 19 VSET 1 18 VCC VREF 2 17 VDD EN/MSEL 3 16 LGATE1 PGND RMPSET 4 15 PHASE1 25 5 14 COMP UGATE1 6 13 FB BOOT1 78 9 10 1112 WQFN-24L 4x4 Functional Pin Description Pin No. Pin Name Pin Function Output Voltage Setting. Connect a voltage divider from VREF to VSET to set the 1 VSET output voltage. Reference Voltage Output (2V). The RT2701 generates a 2V reference voltage 2 VREF from VREF to VRTN. Enable Control Input and Mode Selection. This pin is a tri-state input. Pull up this pin to be higher than 4.2V, the controller operates in DEM mode. Pull up this pin to 3 EN/MSEL between 1.2V to 3V, the controller operates in ASM mode. Pull down this pin to GND, the controller will shutdown. Internal Ramp Slew Rate Setting. Connect a resistor (R ) from RMPSET to GND RMP 4 RMPSET to the ramp slew rate. The value of R must be set equal to R . RMP TON 5 COMP Compensation Node. This pin is the output node of the error amplifier. 6 FB Feedback Voltage Input. This pin is the negative input node of the error amplifier. Remote Differential Feedback, Invert Input. This pin is the negative node of the 7 VRTN differential remote voltage sensing. Switching Frequency Setting. Connect a resistor (R ) from TON to VIN to set the TON 8 TON switching frequency. The value of R must be set equal to R . TON RMP OCP Level Setting. Connect a resistor from OCP to GND to set the current limit 9 OCP threshold. 10 CSN Negative Input of Current Sensing. 11 CSP Positive Input of Current Sensing. Dynamic Phase Control Input. Connect a resistor from PS to GND to set the auto 12 PS down phase threshold. 13 BOOT1 Bootstrap Supply for High Side MOSFET Driver of Phase1. High Side Gate Driver of Phase1. Connect this pin to the Gate of high side 14 UGATE1 MOSFET. Return node of Phase1 High Side Driver. Connect this pin to the Source of high side 15 PHASE1 MOSFET together with the drain of low side MOSFET and the inductor. 16 LGATE1 Low Side Gate Driver of Phase1. Connect this pin to the Gate of low side MOSFET. Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS2701-00 May 2013 2 VRTN RSET TON VID OCP BOOT2 CSN UGATE2 CSP PHASE2 PS LGATE2