ADP3418

Dual Bootstrapped, 12 V MOSFET Driver with Output Disable ADP3418 FEATURES All-in-one synchronous buck driver Bootstrapped high-side drive 1 PWM signal generates both drives Anticross-conduction protection circuitry Output disable control turns off both MOSFETs to float the output per Intel® VR 10 and AMD Opteron™ specifications GENERAL DESCRIPTION The ADP3418 is a dual, high voltage MOSFET driver optimized for driving two N-channel MOSFETs, the two switches in a nonisolated, synchronous, buck power converter. Each of the drivers is capable of driving a 3000 pF load with a 30 ns transition time. One of the drivers can be bootstrapped and is designed to handle the high voltage slew rate associated with floating high-side gate drivers. The ADP3418 includes overlapping drive protection to prevent shoot-through current in the external MOSFETs. The OD pin shuts off both the highside and the low-side MOSFETs to prevent rapid output capacitor discharge during system shutdowns. The ADP3418 is specified over the commercial temperature range of 0°C to 85°C and is available in an 8-lead SOIC package. APPLICATIONS Multiphase desktop CPU supplies Single-supply synchronous buck converters FUNCTIONAL BLOCK DIAGRAM 12V CVCC VCC 4 D1 CBST2 CBST1 Q1 RG RBST1 7 ADP3418 1 BST DRVH IN 2 8 DELAY SW TO INDUCTOR CMP S R Q Q DELAY VCC 6 5 DRVL PGND Q2 CMP 1V 6 3 OD Figure 1. ©2010 SCILLC. All rights reserved. May 2010 – Rev. 6 Publication Order Number: ADP3418/D 03229-B-001 ADP3418 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 4 ESD Caution .................................................................................. 4 Pin Configuration and Function Descriptions ............................. 5 Timing Characteristics..................................................................... 6 Typical Performance Characteristics ............................................. 7 Theory of Operation ........................................................................ 9 Low-Side Driver............................................................................ 9 High-Side Driver ...........................................................................9 Overlap Protection Circuit...........................................................9 Application Information ................................................................ 10 Supply Capacitor Selection ....................................................... 10 Bootstrap Circuit ........................................................................ 10 MOSFET Selection ..................................................................... 10 High-Side (Control) MOSFETs ................................................ 10 Low-Side (Synchronous) MOSFETs .........................................11 PC Board Layout Considerations..............................................11 Outline Dimensions ....................................................................... 13 Ordering Guide .......................................................................... 13 Rev. 6 | Page 2 of 13 | www.onsemi.com ADP3418 SPECIFICATIONS1 VCC = 12 V, BST = 4 V to 26 V, TA = 0°C to 85°C, unless otherwise noted. Table 1. Parameter SUPPLY Supply Voltage Range Supply Current OD INPUT Input Voltage High Input Voltage Low Input Current Propagation Delay Time PWM INPUT Input Voltage High Input Voltage Low Input Current HIGH-SIDE DRIVER Output Resistance, Sourcing Current Output Resistance, Sinking Current Transition Times Propagation Delay2 LOW-SIDE DRIVER Output Resistance, Sourcing Current Output Resistance, Sinking Current Transition Times Propagation Delay2 Timeout Delay Symbol VCC ISYS Conditions Min 4.15 BST = 12 V, IN = 0 V 2.6 −1 tpdhOD tpdlOD See Figure 3 See Figure 3 3.0 −1 VBST − VSW = 12 V VBST − VSW = 12 V See Figure 4, VBST − VSW = 12 V, CLOAD = 3 nF See Figure 4, VBST − VSW = 12 V, CLOAD = 3 nF See Figure 4, VBST − VSW = 12 V VBST − VSW = 12 V 1.8 1.0 35 20 40 20 1.8 1.0 25 21 30 10 240 120 0.8 +1 3.0 2.5 45 30 65 35 3.0 2.5 35 30 60 20 25 20 0.8 +1 40 40 3 Typ Max 13.2 6 Unit V mA V V µA ns ns V V µA Ω Ω ns ns ns ns Ω Ω ns ns ns ns ns ns trDRVH tfDRVH tpdhDRVH tpdlDRVH 10 trDRVL tfDRVL tpdhDRVL tpdlDRVL See Figure 4, CLOAD = 3 nF See Figure 4, CLOAD = 3 nF See Figure 4 See Figure 4 SW = 5 V SW = PGND 5 90 1 2 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC). For propagation delays, tpdh refers to the specified signal going high, and tpdl refers to it going low. Rev. 6 | Page 3 of 13 | www.onsemi.com ADP3418 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter VCC BST DC