Preliminary Technical Data ADP1829, ADP1864 Reference Design FCDC00052 FEATURES Three Output Voltages: 1.24 V, 3.3 V, 5 V Output Current: 2 A to 4 A Input voltage: 10.8-13.2 V Ripple 2% ppk of Output Voltage Transient step ±5%, 50% max load ADP1829, ADP1864 REFERENCE DESIGN DESCRIPTION This ADP1829, ADP1864 Reference Design uses 10.8 V to 13.2 V for the input voltage. The output voltages and currents are as follows: • VOUT1 = 1.24 V with a maximum output current of 4.0 A, • VOUT2 = 3.3 V with a maximum output current of 2.0 A, • VOUT3 = 5.0 V with a maximum output current of 2.0 A, The design criterion is for lowest cost solution. The ripple and transient assumptions are 2% peak to peak voltage ripple and 5% deviation due to 50% instantaneous load step. The switching frequency is fixed at 600 kHz for VOUT1, VOUT2 and VOUT3 Rev. 0 Reference designs are as supplied “as is” and without warranties of any kind, express, implied, or statutory including, but not limited to, any implied warranty of merchantability or fitness for a particular purpose. No license is granted by implication or otherwise under any patents or other intellectual property by application or use of reference designs. 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. Analog Devices reserves the right to change devices or specifications at any time without notice. Trademarks and registered trademarks are the property of their respective owners. Reference designs are not authorized to be used in life support devices or systems. One Technology Way, P.O. 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All rights rese Preliminary Technical Data FCDC00052 TABLE OF CONTENTS Features....................................................................................................................................................................................................... 1 ADP1829, ADP1864 Reference Design Description ........................................................................................................................... 1 Revision History........................................................................................................................................................................................ 2 General Description ................................................................................................................................................................................. 3 ADP1829................................................................................................................................................................................................ 3 ADP1864................................................................................................................................................................................................ 3 Schematic ................................................................................................................................................................................................... 4 Bill of Materials ......................................................................................................................................................................................... 5 TABLE OF FIGURES Figure 1. Schematic 1.24 V @ 4.0 A, 3.3 V @ 2.0 A ........................................................................................................................ 4 Figure 2. Schematic 5.0 V @ 2.0 A .................................................................................................................................................... 4 REVISION HISTORY 8/10/2007—Revision 0: Initial Version Rev. 0 | Page 2 of 6 Preliminary Technical Data FCDC00052 GENERAL DESCRIPTION ADP1829 The ADP1829 is a versatile, dual output, interleaved, synchronous PWM buck controller that generates two independent outputs from an input voltage of 2.9 V to 20 V. Each channel can be configured to provide output voltage from 0.6V to 85% of the input voltage. The two channels operate 180° out of phase, which reduces the current stress on the input capacitor and allows the use of a smaller and lower cost input capacitor. The ADP1829 operates at a pin-selectable fixed switching frequency of either 300 kHz or 600 kHz. For some noise sensitive applications, it can also be synchronized to an external clock to achieve switching frequency between 300 kHz and 1 MHz. The switching frequency chosen is 300 kHz to get good efficiency over a wide range of input and output conditions. The ADP1829 includes an adjustable soft start to limit input inrush current, voltage tracking for sequencing or DDR termination, independent power-good output, and a power enable pin. It also provides current-limit and short-circuit protection by sensing the voltage on the synchronous MOSFET. ADP1864 The ADP1864 is a compact, inexpensive, constant-frequency current-mode step-down dc-to-dc controller. The ADP1864 drives a P-channel MOSFET that regulates an output voltage as low as 0.8 V with ±2% accuracy, for up to 10 A load currents, from input voltages as high as 14 V. The ADP1864 provides system flexibility by allowing accurate setting of the current limit with an external resistor, and the output voltage is easily adjustable using two external resistors. The ADP1864 includes an internal soft start to allow quick power-up while preventing input inrush current. Additional safety features include short-circuit protection, output overvoltage protection, and input undervoltage protection. Current-mode control provides fast and stable load transient performance, while the 580 kHz operating frequency allows a small inductor to be used in the system. To further the life of a battery source, the controller turns on the external P-channel MOSFET 100% of the duty cycle during dropout. Rev. 0 | Page 3 of 6 Preliminary Technical Data FCDC00052 SCHEMATIC Figure 1. Schematic 1.24 V @ 4.0 A, 3.3 V @ 2.0 A 5.0V at 2A 12Vin Cin Cc1 COMP Cc0 Pgate D1 6 U1 Rc IN GND Rf1 Q1 ADP1864 1 L1 Cout1 Rf2 3 FB CS 4 Rf2 Figure 2. Schematic 5.0 V @ 2.0 A Rev. 0 | Page 4 of 6 Vo5V0 Cout2 Preliminary Technical Data FCDC00052 BILL OF MATERIALS Table 1. Vout1, and Vout2 Bill of Materials (1.2 V and 1.8 V) Description Designator Qty Manufacturer MFR# Cap Ceramic C0G 10p 0402 50V Cc0 1 Vishay Generic Cap Ceramic C0G 150p 0402 50V Cc1 1 Vishay Generic Cap Ceramic C0G 22p 0402 50V Cc10, Cc20 2 Vishay Generic Cap Ceramic X7R 1u 0603 16V Cvcc, Cpv 2 Murata GRM188R71C105KA12D Cap Ceramic X7R 47n 0402 10V Css1 1 Vishay Generic Cap Ceramic X5R 4.7u 1206 16V Cin1, Cin11, Cin21 3 Murata grm31cr61c475k Cap Ceramic X5R 22u 1206 6.3V Co11, Co21, Co22 3 TDK C3216X5R0J226M Cap Ceramic X5R 22u 1210 10V Cout1, Cout2 2 TDK C3225X5R1A226M Cap Ceramic X7R 100n 0402 16V Cb1, Cb2 2 Murata GRM155R71C104KA88D Cap Ceramic C0G 33p 0402 50V Clim1, Clim2 2 Vishay Generic Cap Ceramic X7R 15n 0402 16V Css2 1 Vishay Generic Cap ALPOLY 125ºC 180uF 10mm x 7.7mm 16V Cinb1 1 Nippon APXH160ARA181MJ80G Cap Ceramic COG 560p 0402 50V Cc12, Cc21 2 Vishay Generic Cap Ceramic X7R 1.0n 0402 50V Cc11 1 Vishay Generic Cap Ceramic COG 390p 0402 50V Cc22 1 Vishay Generic Diode Schottky 3A SMC 15V D1 1 IR/Vishay 30BQ015 Diode Dual Schottky 200mA SOT-323 30V Db1 1 Diodes inc BAT54AW Inductor Ferrite 7.0uH 10.2mm x 10mm L1, L2 2 Coilcraft MSS1038-702 Inductor Ferrite 1.5uH 10.2mm x 10mm 1 Coilcraft MSS1038-152 Single N-Channel MOSFET SOT-6 30V L3 QH1, QH2, QL1, QL2, QL3 5 Vishay Si3456BDV Single P-Channel MOSFET SOT-6 -30V Q1 1 Vishay Si3457BDV Res 5% Thin Film 33 mOhms 0805 Rcl 1 Susumu RL1220T-R033-J Res 5% Thick Film 10 Ohms 0402 Rin, Rpv 2 Vishay Generic Res 1% Thick Film 10.0k 0402 Rpg1, Rpg2 2 Vishay Generic Res 1% Thick Film 20.0k 0402 Rf11, Rf21 2 Vishay Generic Res 1% Thick Film 4.02k 0402 Rlim1 1 Vishay Generic Res 1% Thick Film 4.12k 0402 Rlim2 1 Vishay Generic Res 1% Thick Film 78.7k 0402 Rc 1 Vishay Generic Res 1% Thick Film 4.42k 0402 Rf12 1 Vishay Generic Res 1% Thick Film 18.7k 0402 Rf22 1 Vishay Generic Res 1% Thick Film 100k 0402 Rf1 1 Vishay Generic Res 1% Thick Film 523k 0402 Rf2 1 Vishay Generic Res 1% Thick Film 10.7k 0402 Rc11 1 Vishay Generic Res 1% Thick Film 93.1 Ohms 0402 Rc12 1 Vishay Generic Res 1% Thick Film 13.7k 0402 Rc21 1 Vishay Generic Res 1% Thick Film 162 Ohms 0402 Rc22 1 Vishay Generic 1 chan 580k PWM TSOT-6 U1 1 Analog ADP1864AUJZ 2 chan 300k to 600k PWM LFCSP-32 U2 Csn1, Csn2, Rsn1, Rsn2 1 Analog ADP1829ACPZ No Stuff Rev. 0 | Page 5 of 6 4 Preliminary Technical Data FCDC00052 NOTES ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB Rev. 0 | Page 6 of 6