ADP1829 & ADP1864 Reference Design

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. Box 9106, Norwood, MA 02062-9106,
U.S.A.
www.analog
Tel: 781.329.4700
Fax: 781.461.3113
©2007 Analog Devices, Inc. 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
Similar pages