DATASHEET ISL6622 FN6470 Rev 2.00 VR11.1 Compatible Synchronous Rectified Buck MOSFET Drivers October 30, 2008 The ISL6622 is a high frequency MOSFET driver designed to Features drive upper and lower power N-Channel MOSFETs in a Dual MOSFET Drives for Synchronous Rectified Bridge synchronous rectified buck converter topology. The advanced PWM protocol of ISL6622 is specifically designed to work Advanced Adaptive Zero Shoot-through Protection with Intersil VR11.1 controllers and combined with Integrated LDO for Selectable Lower Gate Drive Voltage N-Channel MOSFETs, form a complete core-voltage regulator (5.75V, 6.75V, 7.75V) to Optimize Light Load Efficiency solution for advanced microprocessors. When ISL6622 36V Internal Bootstrap Diode detects a PSI protocol sent by an Intersil VR11.1 controller, it activates Diode Emulation (DE) and Gate Voltage Advanced PWM Protocol (Patent Pending) to Support PSI Optimization Technology (GVOT) operation otherwise, it Mode, Diode Emulation, Three-State Operation operates in normal Continuous Conduction Mode (CCM) Diode Emulation for Enhanced Light Load Efficiency PWM mode. Bootstrap Capacitor Overcharging Prevention In the 8 Ld SOIC package, the ISL6622 drives the upper and Supports High Switching Frequency lower gates to VCC during normal PWM mode, while the lower gate drops down to a fixed 5.75V (typically) during PSI - 3A Sinking Current Capability mode. The 10 Ld DFN part offers more flexibility: the upper - Fast Rise/Fall Times and Low Propagation Delays gate can be driven from 5V to 12V via the UVCC pin, while the Integrated High-Side Gate-to-Source Resistor to Prevent lower gate has a resistor-selectable drive voltage of 5.75V, from Self Turn-On due to High Input Bus dV/dt 6.75V, and 7.75V (typically) during PSI mode. This provides Pre-POR Overvoltage Protection for Start-up and the flexibility necessary to optimize applications involving Shutdown trade-offs between gate charge and conduction losses. Power Rails Undervoltage Protection To further enhance light load efficiency, the ISL6622 enables diode emulation operation during PSI mode. This allows Expandable Bottom Copper Pad for Enhanced Heat Discontinuous Conduction Mode (DCM) by detecting when Sinking the inductor current reaches zero and subsequently turning Dual Flat No-Lead (DFN) Package off the low side MOSFET to prevent it from sinking current. - Near Chip-Scale Package Footprint Improves PCB Efficiency and Thinner in Profile An advanced adaptive shoot-through protection is integrated to prevent both the upper and lower MOSFETs from Pb-Free (RoHS Compliant) conducting simultaneously and to minimize dead time. The ISL6622 has a 20k integrated high-side gate-to-source Applications resistor to prevent self turn-on due to high input bus dV/dt. High Light Load Efficiency Voltage Regulators This driver also has an overvoltage protection feature operational while VCC is below the POR threshold: the Core Regulators for Advanced Microprocessors PHASE node is connected to the gate of the low side High Current DC/DC Converters MOSFET (LGATE) via a 10k resistor, limiting the output High Frequency and High Efficiency VRM and VRD voltage of the converter close to the gate threshold of the low side MOSFET, dependent on the current being shunted, Related Literature which provides some protection to the load should the upper MOSFET(s) become shorted. Technical Brief TB363 Guidelines for Handling and Processing Moisture Sensitive Surface Mount Devices (SMDs) Technical Brief TB417 Designing Stable Compensation Networks for Single Phase Voltage Mode Buck Regulators for Power Train Design, Layout Guidelines, and Feedback Compensation Design FN6470 Rev 2.00 Page 1 of 12 October 30, 2008ISL6622 Ordering Information PART NUMBER PART TEMP. RANGE PACKAGE PKG. (Note) MARKING (C) (Pb-Free) DWG. ISL6622CBZ* 6622 CBZ 0 to +70 8 Ld SOIC M8.15 ISL6622CRZ* 622Z 0 to +70 10 Ld 3x3 DFN L10.3x3 ISL6622IBZ* 6622IBZ -40 to +85 8 Ld SOIC M8.15 ISL6622IRZ* 622I -40 to +85 10 Ld 3x3 DFN L10.3x3 *Add -T suffix for tape and reel. Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.. Pinouts ISL6622 ISL6622 (8 LD SOIC) (10 LD 3x3 DFN) TOP VIEW TOP VIEW UGATE 1 8 PHASE 1 10 UGATE PHASE BOOT 2 7 VCC 2 9 BOOT VCC PWM 3 6 LVCC 3 GND 8 GD SEL UVCC 4 7 PWM LVCC GND 4 5 LGATE 5 6 GND LGATE Block Diagrams ISL6622 UVCC BOOT UGATE GD SEL LDO 20k VCC PHASE +5V LVCC SHOOT- 10k THROUGH 11.2k PROTECTION LVCC PWM POR/ CONTROL LOGIC LGATE 9.6k GND UVCC = VCC FOR SOIC LVCC = 5.75V (TYPICALLY) 50mA FOR SOIC FN6470 Rev 2.00 Page 2 of 12 October 30, 2008