ADP1829 Reference Design

ADP1829
FCDC 00085
Preliminary Technical Data
FEATURES
Two Output Voltages: 5.0 V, 3.3 V
Output Current: 2 A
Input voltage: 8.0-16.0 V
Ripple 2% ppk of Output Voltage
Transient step ±5%, 50% max load
ADP1829 DESCRIPTION
This ADP1829 reference design uses 8.0 V to 16.0 V for the input voltage. The output voltages and currents are as follows:
•
VOUT1 = 5.0 V with a maximum output current of 2.0 A,
•
VOUT2 = 3.3 V with a maximum output current of 2.0 A.
Design criteria require no tracking or sequencing. The ripple and transient assumptions are 2% peak to peak voltage ripple
(for the switchers) and 5% deviation due to 50% instantaneous load step respectively. The nominal switching frequency is
fixed at 300 kHz.
Figure 1.
ADP1829 Evaluation Board
Rev. 0
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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
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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.
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©2007 Analog Devices, Inc. All rights reserved.
Preliminary Technical Data
FCDC 00085
TABLE OF CONTENTS
Features....................................................................................................................................................................................................... 1
ADP1829 Description .............................................................................................................................................................................. 1
Revision History........................................................................................................................................................................................ 3
General Description ................................................................................................................................................................................. 4
ADP1829................................................................................................................................................................................................ 4
Schematic ................................................................................................................................................................................................... 5
Bill of Materials ......................................................................................................................................................................................... 6
Assembly Drawing.................................................................................................................................................................................... 7
Powering the ADP1829............................................................................................................................................................................ 8
Input Power Source .............................................................................................................................................................................. 8
Output Load .......................................................................................................................................................................................... 8
Input and Output Voltmeters.............................................................................................................................................................. 8
Turning On the Evaluation Board...................................................................................................................................................... 9
Typical Performance Characteristics.................................................................................................................................................... 10
TABLE OF FIGURES
Figure 1.
ADP1829 Evaluation Board............................................................................................................................................... 1
Figure 2.
Schematic: VOUT1 and VOUT2 ............................................................................................................................................... 5
Figure 3.
Top Assembly Drawing for 1829 Evaluation Board ....................................................................................................... 7
Figure 4.
Bottom Assembly Drawing for 1829 Evaluation Board (looking through from top) ............................................... 7
Figure 5.
Efficiency............................................................................................................................................................................ 10
Figure 6.
Normalized Load Regulation .......................................................................................................................................... 10
Figure 7.
Switching regulator turn on at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin......................................................... 11
Figure 8.
Switching regulator turn on at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin ...................................................... 11
Figure 9.
Switching regulator turn off at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin ....................................................... 12
Figure 10.
Switching regulator turn off at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin.................................................. 12
Figure 11.
Switching regulator ripple and noise at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V...................... 13
Figure 12.
Switching regulator ripple and noise at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V ..................... 13
Figure 13.
Switching regulator ripple and noise at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V ................... 14
Figure 14.
Switching regulator ripple and noise at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V ................... 14
Figure 15.
Transient 50% to 100% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V....................................................... 15
Figure 16.
Transient 50% to 100% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V .................................................... 15
Figure 17.
Transient 100% to 50% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V ...................................................... 16
Figure 18.
Transient 100% to 50% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V .................................................... 16
Rev. 0 | Page 2 of 17
Preliminary Technical Data
FCDC 00085
REVISION HISTORY
11/1/2007—Revision 0: Initial Version
Rev. 0 | Page 3 of 17
Preliminary Technical Data
FCDC 00085
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 18 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.
Rev. 0 | Page 4 of 17
Preliminary Technical Data
FCDC 00085
SCHEMATIC
Figure 2.
Schematic: VOUT1 and VOUT2
Rev. 0 | Page 5 of 17
Preliminary Technical Data
FCDC 00085
BILL OF MATERIALS
Table 1. Vout1, and Vout2 Bill of Materials (Vo5V0 and Vo3V3)
Description
Designator
Qty
Manufacturer
MFR#
Cap Ceramic C0G 68p 0402 50V
C5, C19
2
Vishay
Generic
Cap Ceramic X5R 1u 0603 16V
C2, C15
2
Murata
GRM188R61C105K
Cap Ceramic X5R 1u 0603 25V
C1
1
Murata
GRM188R61E105K
Cap Ceramic X7R 47n 0402 10V
C3, C26
2
Vishay
Generic
Cap Ceramic X7R 22u 1210 25V
C8, C21
2
TDK
C3225X7R1E106K
Cap Polymer 22u 7343 20V
C20
1
Kemet
T520V226M020ATE090
Cap Ceramic X5R 22u 1210 10V
C12, C24
2
TDK
C3225X5R1A226M
Cap Ceramic X7R 100n 0402 16V
C10, C22
2
Murata
GRM155R71C104KA88D
Cap Ceramic C0G 33p 0402 50V
C14, C18
2
Vishay
Generic
Cap Ceramic COG 820p 0402 50V
C6, C16
2
Vishay
Generic
Cap Ceramic X7R 1.8n 0402 50V
C7, C17
2
Vishay
Generic
Diode Dual Schottky 200mA SOT-323 30V
D1
1
Diodes inc
BAT54AW
Inductor Ferrite 15uH 10.0mm x 10.2mm
L1, L2
2
Coilcraft
MSS1038-153NLC
Single N-Channel MOSFET TSOP-6 30V
Q1, Q2, Q3, Q4
4
Vishay
Si3456BDV
Res 5% Thick Film 10 Ohms 0402
R1, R7
2
Vishay
Generic
Res 1% Thick Film 10.0k 0402
R6, R9, R12, R13, R29,
R20
6
Vishay
Generic
Res 1% Thick Film 20.0k 0402
R10, R21
2
Vishay
Generic
Res 1% Thick Film 2.74k 0402
R2
1
Vishay
Generic
Res 1% Thick Film 44.2 Ohms 0402
R11, R22
2
Vishay
Generic
Res 1% Thick Film 4.42k 0402
R19, R23, R24
3
Vishay
Generic
2 chan 300k to 600k PWM LFCSP-32
U1
1
Analog
ADP1829ACPZ
Res 0 Ohm jumper 0402
R5, R14, R15, R18, R25
5
Vishay
Generic
No Stuff
R31, R32, C13, C25,
R16, R26, C11, C23
8
Rev. 0 | Page 6 of 17
Preliminary Technical Data
FCDC 00085
ASSEMBLY DRAWING
Figure 3.
Figure 4.
Top Assembly Drawing for 1829 Evaluation Board
Bottom Assembly Drawing for 1829 Evaluation Board (looking through from top)
Rev. 0 | Page 7 of 17
Preliminary Technical Data
FCDC 00085
POWERING THE ADP1829
The ADP1829 is supplied fully assembled.
INPUT POWER SOURCE
1.
Before connecting the power source to the ADP1829, make sure that it is turned off. If the input power source
includes a current meter, use that meter to monitor the input current.
2.
Connect the positive terminal of the power source to the VIN terminal on the evaluation board, and the negative
terminal of the power source to the GND terminal just below the VIN terminal.
3.
If the power source does not include a current meter, connect a current meter in series with the input source voltage.
4.
Connect the positive lead (+) of the power source to the ammeter positive (+) connection, the negative lead (−) of the
power source to the GND pins on the board, and the negative lead (−) of the ammeter to the VIN pins on the board.
OUTPUT LOAD
1.
Although the ADP1829 can sustain the sudden connection of the load, it is possible to damage the load if it is not
properly connected.
2.
Make sure that the board is turned off before connecting the load.
a)
If the load includes an ammeter, or if the current is not measured, connect the load directly to the evaluation
board with the positive (+) load connection to the VOUT pins and negative (−) load connection to the GND pins
next to the VOUT pins.
b)
If an ammeter is used, connect it in series with the load; connect the positive (+) ammeter terminal to the
evaluation board VOUT pins, the negative (−) ammeter terminal to the positive (+) load terminal, and the negative
(−) load terminal to the evaluation board GND pins next to the VOUT pins.
c)
Repeat for the other VOUT channel.
Once the loads are connected, make sure that they are set to the proper current before powering the ADP1829.
INPUT AND OUTPUT VOLTMETERS
Measure the input and output voltages with voltmeters.
1.
2.
Connect the voltmeter measuring the input voltage with the positive (+) lead connected to the VIN pins on the test
board and the negative lead (−) connected to the GND test point between the inductors (TP13 or TP21).
Connect the voltmeter measuring VOUT1 with the positive lead (+) connected to the test point near the VOUT1 pins
(TP9) and the negative lead (−) connected to the adjacent GND test point (TP13).
3.
Connect the voltmeter measuring VOUT2 in the same manner (between TP8 and TP21).
4.
Make sure to connect the voltmeters to the appropriate evaluation board test points and not to the load or power
source themselves.
5.
If the voltmeters are not connected directly to the evaluation board at these connection points, the measured voltages
will be incorrect due to the voltage drop across the leads connecting the evaluation board to both the source and load.
Rev. 0 | Page 8 of 17
Preliminary Technical Data
FCDC 00085
TURNING ON THE EVALUATION BOARD
Once the power source and loads are connected to the ADP1829, the board can be powered for operation. Slowly increase
the input power source voltage until the input voltage exceeds the minimum input operating voltage of 8.0 V. If the load is
not already enabled, enable the load and check that it is drawing the proper current and that the output voltage maintains
voltage regulation.
Rev. 0 | Page 9 of 17
Preliminary Technical Data
FCDC 00085
TYPICAL PERFORMANCE CHARACTERISTICS
Switching Regulators Efficiency
99.0%
97.0%
Efficiency
95.0%
93.0%
16Vin Efficiency
8Vin Efficiency
91.0%
89.0%
87.0%
85.0%
0%
20%
40%
60%
80%
100%
120%
% of full load of switching regulators
Figure 5.
Efficiency
Switching Regulators Load Regulation
1.01
1.008
Vout normalized
1.006
1.004
16Vin 5Vout load reg
1.002
16Vin 3.3Vout load reg
8Vin 5Vout load reg
1
8Vin 3.3Vout load reg
0.998
0.996
0.994
0.992
0%
20%
40%
60%
80%
% of full load of switching regulators
Figure 6.
Normalized Load Regulation
Rev. 0 | Page 10 of 17
100%
120%
Preliminary Technical Data
FCDC 00085
Figure 7.
Switching regulator turn on at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin
Figure 8.
Switching regulator turn on at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin
Rev. 0 | Page 11 of 17
Preliminary Technical Data
Figure 9.
FCDC 00085
Switching regulator turn off at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin
Figure 10. Switching regulator turn off at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin
Rev. 0 | Page 12 of 17
Preliminary Technical Data
FCDC 00085
Figure 11. Switching regulator ripple and noise at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V
Figure 12. Switching regulator ripple and noise at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V
Rev. 0 | Page 13 of 17
Preliminary Technical Data
FCDC 00085
Figure 13. Switching regulator ripple and noise at no load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V
Figure 14. Switching regulator ripple and noise at full load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V
Rev. 0 | Page 14 of 17
Preliminary Technical Data
FCDC 00085
Figure 15. Transient 50% to 100% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V
Figure 16. Transient 50% to 100% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V
Rev. 0 | Page 15 of 17
Preliminary Technical Data
FCDC 00085
Figure 17. Transient 100% to 50% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 8.0 V
Figure 18. Transient 100% to 50% load: Ch1 = 3.3 V, Ch2 = 5.0 V, Ch4 = Vin @ 16.0 V
Rev. 0 | Page 16 of 17
Preliminary Technical Data
FCDC 00085
NOTES
©2007 Analog Devices, Inc. All rights reserved.
Trademarks and registered trademarks are the
property of their respective owners.
EB
Rev. 0 | Page 17 of 17
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