Digital Multi-Phase Buck Controller FEATURES DESCRIPTION 5-phase dual output PWM Controller Phases are flexibly assigned between Loops 1 & 2 Intel® VR12, AMD® 400kHz & 3.4MHz SVI and Memory modes Dual OCP support for I-spike enhanced AMD CPUs SMB_Alert Pin for Servers PMBus Address pin or Variable Gate Drive Overclocking & Gaming Mode with Vmax setting Switching frequency from 200kHz to 1.2MHz per phase IR Efficiency Shaping Features including Variable Gate Drive and Dynamic Phase Control Programmable 1-phase or 2-phase for Light Loads and Active Diode Emulation for Very Light Loads IR Adaptive Transient Algorithm (ATA) on both loops minimizes output bulk capacitors and system cost Auto-Phase Detection with auto-compensation Per-Loop Fault Protection: OVP, UVP, OCP, OTP, CFP I2C/SMBus/PMBus system interface for telemetry of Temperature, Voltage, Current & Power for both loops Non-Volatile Memory (NVM) for custom configuration Compatible with IR ATL and 3.3V Tri-state Drivers +3.3V supply voltage; -20ºC to 85ºC ambient operation Pb-Free, RoHS, 6x6 40-pin QFN, MSL2 package IR3541A A/B The IR3541A is a dual-loop, digital multi-phase buck controller that drive up to 5 phases. The IR3541A is fully Intel® VR12 and AMD® SVI compliant on both loops and provides a Vtt tracking function for DDR memory. NVM storage saves pins and enables a small package size. The IR3541A includes the IR Efficiency Shaping Technology to deliver exceptional efficiency at minimum cost across the entire load range. IR Variable Gate Drive optimizes the MOSFET gate drive voltage as a function of real-time load current. IR Dynamic Phase Control adds/drops active phases based upon load current. The IR3541A can be configured to enter 1-phase operation and active diode emulation mode automatically or by command. IR’s unique Adaptive Transient Algorithm (ATA), based on proprietary non-linear digital PWM algorithms, minimizes output bulk capacitors. The I2C/PMBus interface can communicate with up to 16 IR3541A based VR loops. Device configuration and fault parameters are easily defined using the IR Intuitive Power Designer (DPDC) GUI and stored in on-chip NVM. The IR3541A also includes numerous features like register diagnostics for fast design cycles and platform differentiation, truly simplifying VRD design and enabling fastest time-to-market with its “set-and-forget” methodology. PIN DIAGRAM APPLICATIONS Intel ® VR12 & AMD® SVI based systems DDR Memory with Vtt tracking IR3541A Overclocked & Gaming platforms Figure 1: IR3541A Package Top View 1 June 21, 2013 | FINAL | V1.09 Digital Multi-Phase Buck Controller IR3541A A/B ORDERING INFORMATION IR3541AM Package Packing Qty Part Number QFN TR=3000 TY=4900 IR3541AMTRPBF IR3541AMTYPBF QFN TR=3000 IR3541AMxxyyTRP P/PBF – Lead Free TR – Tape & Reel / TY - Tray yy – Configuration File ID xx – Customer ID IR3541A Figure 2: IR3541A Package Top View, Enlarged June 21, 2013 | FINAL | V1.09 Default 1 Customer Configuration Notes: 1. xx = Customer ID and yy = Configuration File (Codes assigned by IR Marketing). Package Type (QFN) 2 Programming Digital Multi-Phase Buck Controller FUNCTIONAL BLOCK DIAGRAM V18A RCSP_L2 IR3541A A/B VCC VID_2 RSCM_L2 1.8V AFE_2 LDO VSEN_L2 VRTN_L2 ITOT_2 Vout1_Error Voltage ADC RCSP PWM1 RSCM Vout2_Error AFE_1 PWM2 VSEN VID_1 VRTN PWM3 PWM Generator ISEN1 PWM4 IP1 Mode Control IRTN1 PWM5 ISEN2 Control and Monitoring IP2 IRTN2 Σ ISEN3 Phase_ Period_1 Phase_ Period_2 VAR_GATE_PM_ADDR (CHL8325A) ITOT_1 IP3 IRTN3 ISEN4 Iout IP4 Vin IRTN4 ITOT_2 ISEN5 IP5 IRTN5 Σ Vout Temp Current ADC Fault Bus System Clock IP1 IP2 IP3 System Clock ADC Clocks IP4 MUX Clocks IP5 Phase_Period_1 TSEN2 (CHL8325B) Phase_Period_2 TSEN VINSEN Monitor ADC V3_3 SMB_DIO SMB_CLK SV_CLK1/SVC2 SV_DIO1/SVD2 EN Reference, Oscillator, State Control, Interfaces, Registers and NVM VID_1 VID_2 Iout Vin Temp Fault Bus SMB_ALERT# SV_ALERT#1/VFIXEN2 VR_HOT#1/VRHOT_ICRIT#2 VR_READY_L11/PWRGD2 VR_READY_L21/PWROK2 Notes 1 Pin definition in Intel & MPoL modes 2 Pin definition in AMD mode RRES Figure 4: IR3541A Functional Block Diagram 3 June 21, 2013 | FINAL | V1.09