Dual, Interleaved, Step-Down DC-to-DC Controller with Tracking Data Sheet ADP1829 FEATURES TYPICAL APPLICATION CIRCUIT V = 12V IN Fixed frequency operation: 300 kHz, 600 kHz, or 180F 180F synchronized operation up to 1 MHz 1F Supply input range: 3.0 V to 20 V EN1 PV IN TRK1 Wide power stage input range: 1 V to 24 V EN2 TRK2 Interleaved operation results in smaller, low cost VREG input capacitor BST2 BST1 0.47F All-N-channel MOSFET design for low cost 0.47F IRLR7807Z DH2 IRLR7807Z 0.85% accuracy at 0C to 70C DH1 Soft start, thermal overload, current-limit protection ADP1829 1.2V, 1.8V, 2.2H 2.2H 6A 8A 10 A shutdown supply current SW1 SW2 Internal linear regulator 2k 2k CSL1 CSL2 560F 560F Lossless R current-limit sensing DSON DL2 DL1 2k 2k IRFR3709Z Reverse current protection during soft start for handling IRFR3709Z PGND2 precharged outputs FB2 PGND1 390pF Independent Power OK outputs 1k FB1 COMP2 Voltage tracking for sequencing or DDR termination 390pF Available in 5 mm 5 mm, 32-lead LFCSP 2k COMP1 3900pF 4. 53k FREQ APPLICATIONS 4. 53k 3900pF LDOSD Telecommunications and networking systems GND SYNC Medical imaging systems Base station power Set-top boxes Figure 1. Printers DDR termination GENERAL DESCRIPTION The ADP1829 is a versatile, dual, interleaved, synchronous also be synchronized to an external clock to achieve switching PWM buck controller that generates two independent output frequencies between 300 kHz and 1 MHz. The ADP1829 rails from an input of 3.0 V to 20 V, with power input voltage includes soft start protection to prevent inrush current from the ranging from 1.0 V to 24 V. Each controller can be configured input supply during startup, reverse current protection during to provide output voltages from 0.6 V to 85% of the input soft start for precharged outputs, as well as a unique adjustable voltage and is sized to handle large MOSFETs for point-of-load lossless current-limit scheme utilizing external MOSFET sensing. regulators. The two channels operate 180 out of phase, For applications requiring power supply sequencing, the reducing stress on the input capacitor and allowing smaller, low ADP1829 also provides tracking inputs that allow the output cost components. The ADP1829 is ideal for a wide range of voltages to track during startup, shutdown, and faults. This high power applications, such as DSP and processor core I/O feature can also be used to implement DDR memory bus power, and general-purpose power in telecommunications, termination. medical imaging, PC, gaming, and industrial applications. The ADP1829 is specified over the 40C to +125 C junction The ADP1829 operates at a pin-selectable, fixed switching temperature range and is available in a 32-lead LFCSP package. frequency of either 300 kHz or 600 kHz, minimizing external component size and cost. For noise-sensitive applications, it can Rev. D 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 20072016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 06784-001ADP1829 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Tracking ....................................................................................... 14 Applications ....................................................................................... 1 MOSFET Drivers ........................................................................ 15 Typical Application Circuit ............................................................. 1 Current Limit .............................................................................. 15 General Description ......................................................................... 1 Applications Information .............................................................. 16 Revision History ............................................................................... 2 Selecting the Input Capacitor ................................................... 16 Specifications ..................................................................................... 3 Selecting the MOSFETs ............................................................. 17 Absolute Maximum Ratings ............................................................ 5 Setting the Current Limit .......................................................... 18 ESD Caution .................................................................................. 5 Feedback Voltage Divider ......................................................... 18 Functional Block Diagram .............................................................. 6 Compensating the Voltage Mode Buck Regulator ................. 19 Pin Configuration and Function Descriptions ............................. 7 Soft Start ...................................................................................... 22 Typical Performance Characteristics ............................................. 9 Voltage Tracking ......................................................................... 22 Theory of Operation ...................................................................... 13 Coincident Tracking .................................................................. 23 Input Power ................................................................................. 13 Ratiometric Tracking ................................................................. 23 Start-Up Logic ............................................................................. 13 Thermal Considerations ............................................................ 24 Internal Linear Regulator .......................................................... 13 PCB Layout Guidelines .................................................................. 25 Oscillator and Synchronization ................................................ 13 LFCSP Package Considerations ................................................ 25 Error Amplifier ........................................................................... 14 Application Circuits ....................................................................... 26 Soft Start ...................................................................................... 14 Outline Dimensions ....................................................................... 28 Power OK Indicator ................................................................... 14 Ordering Guide .......................................................................... 28 REVISION HISTORY 4/16Rev. C to Rev. D 4/09Rev. 0 to Rev. A Changes to Figure 3 .......................................................................... 7 Changes to Features and General Description Sections .............. 1 Updated Outline Dimensions ....................................................... 28 Changes to IN Input Voltage EN1, IN2 Input High Voltage Changes to Ordering Guide .......................................................... 28 EN1, EN2 Input Low Voltage and EN1, EN2 Input Impedance to 5 V Zener Parameters, Table 1 .................................................... 3 10/12Rev. B to Rev. C Changes to Table 2 ............................................................................. 5 Changes to PCB Layout Guidelines Section ............................... 25 Changes to Table 3 ............................................................................. 7 Updated Outline Dimensions ....................................................... 28 Changes to Theory of Operation Section, Input Power Section, Changes to Ordering Guide .......................................................... 28 and Start-Up Logic Section ........................................................... 13 Changes to Ordering Guide .......................................................... 29 1/11Rev. A to Rev. B Changes to VREG Short-Circuit Current Parameter, Table 1 .... 3 6/07Revision 0: Initial Version Changes to Figure 3 and Table 3 ..................................................... 7 Added Exposed Paddle Notation to Outline Dimensions ........ 29 Rev. D Page 2 of 28