Synchronous Buck PWM, Step-Down, DC-to-DC Controller Data Sheet ADP1828 to regulate an output voltage as low as 0.6 V to 85% of the input FEATURES voltage and is sized to handle large MOSFETs for point-of-load Wide bias voltage range 3.0 V to 20 V regulators. The ADP1828 is ideal for a wide range of high power Wide power stage input range 1 V to 24 V applications, such as DSP and processor core I/O power, and Wide output voltage range: 0.6 V to 85% of input voltage general-purpose power in telecommunications, medical imaging, o o 0.85% accuracy at 0 C to 70 C PC, gaming, and industrial applications. It operates from input All N-channel MOSFET design for low cost bias voltages of 3 V to 20 V with an internal LDO that generates Fixed-frequency operation at 300 kHz, 600 kHz, or resistor a 5 V output for input bias voltages greater than 5.5 V. adjustable 300 kHz to 600 kHz Clock output for synchronizing other controllers The ADP1828 operates at a pin-selectable, fixed switching No current sense resistor required frequency of either 300 kHz or 600 kHz, or at any frequency Internal linear regulator between 300 kHz and 600 kHz with a resistor. The switching Voltage tracking for sequencing frequency can also be synchronized to an external clock up to Soft start and thermal overload protection 2 the nominal oscillator frequency of the device The clock Overvoltage and undervoltage power-good indicator output can e used for synchronizing additional ADP1828s (or 15 A shutdown supply current the ADP1829 controllers), thus eliminating the need for an Available in a 20-lead QSOP and 20-lead, 4 mm 4 mm LFCSP external clock source. The ADP1828 includes soft start protection to limit any inrush current from the input supply during startup, APPLICATIONS reverse current protection during soft start for a precharged Telecom and networking systems output, as well as a unique adjustable lossless current-limit Base station power scheme utilizing external MOSFET R sensing. DSON Set-top boxes, game consoles For applications requiring power-supply sequencing, the ADP1828 Printers and copiers provides a tracking input that allows the output voltage to track Medical imaging systems during startup, shutdown, and faults. The additional supervisory DSP and microprocessor core power supplies and control features include thermal overload, undervoltage DDR termination lockout, and power good. GENERAL DESCRIPTION The ADP1828 operates over the 40C to +125C junction temper- The ADP1828 is a versatile and synchronous PWM voltage ature range and is available in a 20-lead QSOP and 20-lead, 4 mm mode buck controller. It drives an all N-channel power stage 4 mm LFCSP. V = 10V TO 18V IN C IN 180F C7 2 C5 1F 20V 1F D1 VREG PV TRKBST C4 0.47F M1 IN DH ADP1828 OUTPUT L1 = 0.82H 1.8V, 20A C6 SW EN R CL 1F R6 CSL C C OUT1 100k FREQ 1.8k OUT2 R3 47F DL M2 1000F 7.5k 2 2 X5R SYNC 6.3V C1 PGND R1 680pF PGOOD 20k FB COMP R2 CLKOUT 10k R8 SS CLKSET 20k AGND PGND C2 C 33pF SS 200nF GND C3 5.6nF AGND f = 300kHz D1: BAT54 SW C : SANYO, OSCON 20SP180M M1: INFINEON, BSC080N03LS IN C : SANYO, POSCAP 2R5TPD1000M5 M2: INFINEON, 2 BSC030N03LS OUT2 L1: WURTH ELEKTRONIC, 0.82H, 744355182 Figure 1. Typical Application Circuit with 20 A Output Rev. E Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20072018 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 06865-001ADP1828 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Shutdown Control ...................................................................... 18 Applications ....................................................................................... 1 Tracking ....................................................................................... 18 General Description ......................................................................... 1 Application Information ................................................................ 19 Revision History ............................................................................... 2 Selecting the Input Capacitor ................................................... 19 Specifications ..................................................................................... 3 Output LC Filter ......................................................................... 19 Absolute Maximum Ratings ............................................................ 6 Selecting the MOSFETs ............................................................. 20 ESD Caution .................................................................................. 6 Setting the Current Limit .......................................................... 21 Simplified Block Diagram ............................................................... 7 Accurate Current-Limit Sensing .............................................. 21 Pin Configurations and Function Descriptions ........................... 8 Feedback Voltage Divider ......................................................... 21 Typical Performance Characteristics ........................................... 10 Compensating the Voltage Mode Buck Regulator ................. 21 Theory of Operation ...................................................................... 15 Soft Start ...................................................................................... 25 Input Power ................................................................................. 15 Switching Noise and Overshoot Reduction ............................ 25 Internal Linear Regulator .......................................................... 15 Voltage Tracking ......................................................................... 25 Soft Start ...................................................................................... 15 Coincident Tracking .................................................................. 26 Error Amplifier ........................................................................... 16 Ratiometric Tracking ................................................................. 26 Current-Limit Scheme ............................................................... 16 Thermal Considerations ............................................................ 28 MOSFET Drivers ........................................................................ 16 PCB Layout Guideline ................................................................... 29 Setting the Output Voltage ........................................................ 17 Recommended Component Manufacturers ........................... 30 Switching Frequency Control and Synchronization .............. 17 Application Circuits ....................................................................... 31 Compensation ............................................................................. 18 Outline Dimensions ....................................................................... 33 Power-Good Indicator ............................................................... 18 Ordering Guide .......................................................................... 33 Thermal Shutdown ..................................................................... 18 REVISION HISTORY 8/2018Rev. D to Rev. E 6/2009Rev. A to Rev. B Updated Outline Dimensions ....................................................... 33 Changes to Figure 40 ...................................................................... 24 Changes to Ordering Guide .......................................................... 33 4/2009Rev. 0 to Rev. A 2/2017Rev. C to Rev. D Changes to Features Section and General Description Section ..... 1 Updated Outline Dimensions ....................................................... 33 Changes to IN Input Voltage Parameter and EN Input Impedance Changes to Ordering Guide .......................................................... 34 to 5 V Zener Parameter, Table 1 ...................................................... 3 Changes to Table 2 ............................................................................. 6 11/2010Rev. B to Rev. C Changes to Table 3 ............................................................................. 8 Added 20-Lead LFCSP WQ ............................................. Universal Changes to Theory of Operation Section and Input Power Changes to Features and General Description Sections .............. 1 Section .............................................................................................. 14 Changes to MOSFET Drivers Section ......................................... 15 Changes to Table 2 ............................................................................ 6 Added Figure 4 Renumbered Sequentially .................................. 8 Updated Outline Dimensions ....................................................... 32 Changes to Table 3 ............................................................................ 8 Changes to Ordering Guide .......................................................... 32 Updated Outline Dimensions ....................................................... 33 Added Figure 59 Renumbered Sequentially .............................. 33 9/2007Revision 0: Initial Version Changes to Ordering Guide .......................................................... 34 Rev. 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