Datasheet ADP1829 (Analog Devices)

Dual, Interleaved, Step-Down DC-to-DC Control er with Tracking Data Sheet ADP1829 FEATURES TYPICAL APPLICATION CIRCUIT Fixed frequency operation: 300 kHz, 600 kHz, or VIN = 12V synchronized operation up to 1 MHz 180µF 180µF 1µF Supply input range: 3.0 V to 20 V PV IN EN1 Wide power stage input range: 1 V to 24 V TRK1 EN2 Interleaved operation results in smaller, low cost TRK2 VREG input capacitor BST2 All-N-channel MOSFET design for low cost BST1 0.47µF 0.47µF ±0.85% accuracy at 0
°
C to 70
°
C IRLR7807Z DH1 DH2 IRLR7807Z Soft start, thermal overload, current-limit protection ADP1829 1.2V, 1.8V, 10 µA shutdown supply current 2.2µH 2.2µH 6A 8A SW1 SW2 Internal linear regulator 2kΩ 2kΩ Lossless R CSL1 CSL2 560µF 560µF DSON current-limit sensing DL1 DL2 2kΩ 2kΩ Reverse current protection during soft start for handling IRFR3709Z IRFR3709Z PGND2 precharged outputs FB2 Independent Power OK outputs PGND1 390pF Voltage tracking for sequencing or DDR termination FB1 COMP2 1kΩ 390pF Available in 5 mm × 5 mm, 32-lead LFCSP 2kΩ COMP1 3900pF 4.53kΩ APPLICATIONS FREQ 4.53kΩ 3900pF Telecommunications and networking systems LDOSD GND SYNC Medical imaging systems
001
Base station power
06784-
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 al ow 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 −40°C 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 rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2007–2016 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
Document Outline FEATURES APPLICATIONS TYPICAL APPLICATION CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION INPUT POWER START-UP LOGIC INTERNAL LINEAR REGULATOR OSCILLATOR AND SYNCHRONIZATION ERROR AMPLIFIER SOFT START POWER OK INDICATOR TRACKING MOSFET DRIVERS CURRENT LIMIT APPLICATIONS INFORMATION SELECTING THE INPUT CAPACITOR Selecting the Output LC Filter SELECTING THE MOSFETS SETTING THE CURRENT LIMIT FEEDBACK VOLTAGE DIVIDER COMPENSATING THE VOLTAGE MODE BUCK REGULATOR Type II Compensator Type III Compensator SOFT START VOLTAGE TRACKING COINCIDENT TRACKING RATIOMETRIC TRACKING Setting the Channel 2 Undervoltage Threshold for Ratiometric Tracking THERMAL CONSIDERATIONS PCB LAYOUT GUIDELINES LFCSP PACKAGE CONSIDERATIONS APPLICATION CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE