an1517

Application Note 1517
ZL2008EVAL1Z Evaluation Board
Description
Features
The ZL2008 is an integrated mixed-signal power
conversion and management IC that combines an
efficient step-down DC/DC converter with key power and
thermal management functions in a single package. The
ZL2008 incorporates current sharing and adaptive
efficiency-optimization algorithms to provide a flexible,
efficient power IC building block.
• 15A synchronous buck converter
The ZL2008EVAL1Z platform is a 4-layer board
demonstrating a 15A synchronous buck converter.
Sequencing, tracking, margining, plus other features can
be evaluated using this board.
• Power good indicator
A USB to SMBus adapter board can be used to connect
the eval board to a PC. The PMBus command set is
accessed by using the Zilker Labs PowerNavigator™
evaluation software from a PC running Microsoft
Windows.
• VOUT = 1.2V/15A (20A max)
• Optimized for small circuit footprint and dynamic
response
• Configurable through SMBus
• Onboard enable switch
Target Specifications
• VIN = 12V
• fsw = 615kHz
• Efficiency: 86% at 10A
• Output ripple: ±1%
• Dynamic response: ±3%
(50%-100%-50% load step, di/dt = 2.5A/μs)
• Board temperature: +25°C
VIN
EN
S Y NC
ZL2008
VOUT
DDC
S MB us
ENABLE
PINSTRAP
VTRK
SW 1
J10
J11
S Y NC
DDC
S MB us
TRA CK
PG
S Y NC
DDC
S MB us
TRA CK
PG
FIGURE 1. ZL2008EVAL1Z BLOCK DIAGRAM
March 15, 2010
AN1517.1
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Application Note 1517
Functional Description
The ZL2008EVAL1Z provides all circuitry required to
demonstrate the features of the ZL2008. The
ZL2008EVAL1Z has a functionally-optimized ZL2008
circuit layout that allows efficient operation up to the
maximum output current. Power and load connections
are provided through plug-in sockets.
A majority of the features of the ZL2008 such as softstart delay and ramp times, supply sequencing, voltage
tracking, and voltage margining are available on this
evaluation board. For voltage tracking and sequencing
evaluation, the board can be connected to any other
Zilker Labs evaluation board that supports the Digital DC
(DDC) bus.
the eval software or by loading a predefined scenario
from a configuration file.
Use the mouse-over pop-ups for PowerNavigator help.
Refer to Zilker Labs application note AN2033 for PMBus
details.
The ENABLE switch can then be moved to “ENABLE” and
the ZL2008EVAL1Z board can be tested. Alternately, the
PMBus ON-OFF CONFIG and OPERATION commands may
be used.
Quick Start Guide
Stand Alone Operation
1. Set ENABLE switch to “DISABLE”
Figure 1 shows a functional block diagram of the
ZL2008EVAL1Z board. The SMBus address is selectable
through a jumper on the top side of the board. All power
to the board (VIN and I2C bus) must be removed before
changing the jumpers.
2. Apply load to VOUT+/VOUT-
The hardware enable function is controlled by a toggle
switch on the ZL2008EVAL1Z board. The power good
(PG) LEDs indicate the correct state of PG when external
power is applied to the ZL2008EVAL1Z board. The right
angle headers at opposite ends of the board are for
connecting a USB to SMBus adapter board or for daisy
chaining of multiple evaluation boards.
5. Connect power supply to VIN+/VIN- (supply turned
off)
Figure 2 shows the operational circuit. The circuit
consists of the ZL2008 IC with its minimal component
count to realize a 15A buck converter. The board layout
has been optimized for thermal performance. Figure 3 is
the board interface circuitry. Figure 4 through Figure 8
show the PCB layout for the board including the board
fabrication notes.
The bill of materials (BOM) and configuration file are also
included for reference.
Operation
3. Connect the USB to SMBus adapter board to J10 of
ZL2008EVAL1Z
4. Connect supplied USB cable from computer to USB
to SMBus adapter board
6. Turn power supply on
7. Set ENABLE switch to “ENABLE”
8. Monitor ZL2008EVAL1Z board operation using an
oscilloscope
USB (PMBus) Operation
1. Set ENABLE switch to “DISABLE”
2. Apply load to VOUT+/VOUT3. Connect power supply to VIN+/VIN- (supply turned
off)
4. Turn power supply on
5. Insert the Zilker Labs Eval Kit CD
6. Connect USB to SMBus adapter board to J10 of
ZL2008EVAL1Z
7. Connect supplied USB cable from computer to USB
to SMBus adapter board
PMBus Operation
The ZL2008 utilizes the PMBus protocol. The PMBus
functionality can be controlled via USB from a PC running
the PowerNavigator evaluation software in a Windows XP
or Windows 2000/NT operating system.
Install the evaluation software using the CD included in
the ZL2008EVAL1Z kit.
For board operation, connect the included USB-to-SMBus
adapter board to J10 of the ZL2008EVAL1Z board.
Connect the desired load and an appropriate power
supply to the input and connect the included USB cable
to the PC running the PowerNavigator evaluation
software. Place the ENABLE switch in “DISABLE” and turn
on the power.
The evaluation software allows modification of all ZL2008
PMBus parameters. The ZL2008 device on the board has
been pre-configured as described in this document, but
the user may modify the operating parameters through
2
- Upon first-time connection, the Found New
Hardware Wizard will appear.
- Windows XP users: Select ‘No’ at prompt to
search the Internet for drivers.
- Follow the steps on the screen to install the
drivers from the CD.
8. Install the PowerNavigator evaluation software by
running setup.exe from the
PowerNavigator_installer folder on the CD.
9. Set ENABLE switch on EVB to “ENABLE”
10.Monitor and configure the ZL2008EVAL1Z board
using PMBus commands in the evaluation software
11.Test the ZL2008EVAL1Z operation using an
oscilloscope and the evaluation software.
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Board Schematics
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FIGURE 2. ZL2008EVAL1Z OPERATIONAL CIRCUIT
Board Schematics (Continued)
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FIGURE 3. ZL2008EVAL1Z INTERFACE CIRCUITRY
Application Note 1517
Board Layout – 4 Layers
FIGURE 4. PCB – TOP LAYER
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Board Layout – 4 Layers (Continued)
FIGURE 5. PCB – INNER LAYER 1 (VIEWED FROM TOP)
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Board Layout – 4 Layers (Continued)
FIGURE 6. PCB – INNER LAYER 2 (VIEWED FROM TOP)
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Board Layout – 4 Layers (Continued)
FIGURE 7. PCB – BOTTOM LAYER (VIEWED FROM TOP)
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Application Note 1517
FIGURE 8. BOARD FABRICATION NOTES
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Bill of Materials
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Application Note 1517
Configuration Text
The following configuration text is loaded into the ZL2008 device on the ZL2008EVAL1Z. The configuration is stored in
the DEFAULT store. Each PMBus command can be viewed via the PowerNavigator software. The text following the #
symbol is used for a comment.
#ZL2008
#PowerPlan file
#11/30/2009
#NOTE: This file is intended for the ZL2008EVAL1Z
#with L=400nH, Co=5x(100uF/2.0mohm)+(2X680uF/10mohm)
#Configuration File Format:
#PMBus Command <tab> Hex Value
#Erase user store & default store
RESTORE_FACTORY
STORE_USER_ALL
STORE_DEFAULT_ALL
MFR_ID
MFR_MODEL
MFR_REVISION
MFR_LOCATION
#MFR_DATE
Zilker_Labs
ZL2008EVAL1Z
Rev7
Austin_TX
VOUT_COMMAND
1.20#V
IOUT_SCALE
IOUT_CAL_OFFSET
0.7
2
#mOhm
#A
IOUT_OC_FAULT_LIMIT
IOUT_AVG_OC_FAULT_LIMIT
IOUT_UC_FAULT_LIMIT
IOUT_AVG_UC_FAULT_LIMIT
MFR_IOUT_OC_FAULT_RESPONSE
MFR_IOUT_UC_FAULT_RESPONSE
45.0
38.0
-15.0
-12.0
0x80
0x80
#A
#A
#A
#A
VIN_OV_FAULT_LIMIT
VIN_OV_WARN_LIMIT
VIN_OV_FAULT_RESPONSE
VIN_UV_WARN_LIMIT
VIN_UV_FAULT_LIMIT
VIN_UV_FAULT_RESPONSE
14.0
13.5
0x80
4.641
4.50
0x80
#V
#V
#V
#V
POWER_GOOD_DELAY
TON_DELAY
TON_RISE
TOFF_DELAY
TOFF_FALL
1
5
5
5
5
DEADTIME
DEADTIME_CONFIG
0x2424
0x0404
MAX_DUTY
INDUCTOR
95
0.4
#uH
FREQUENCY_SWITCH
400
#kHz
PID_TAPS
A=13682.50, B=-23641.00, C=9993.75
11
#ms
#ms
#ms
#ms
#ms
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Application Note 1517
Configuration Text (Continued)
# Advanced
USER_CONFIG
MFR_CONFIG
#NLR_CONFIG
TEMPCO_CONFIG
0x6010
0x6AD5
0xE1060C00
0xA8
# Advanced 2
MISC_CONFIG
DDC_CONFIG
DDC_GROUP
0x0080
0x0101
0x00000000
STORE_DEFAULT_ALL
RESTORE_DEFAULT_ALL
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Application Note 1517
Measured Data
The following data was acquired using a ZL2008EVAL1Z rev 2 evaluation board.
Efficiency
Adaptive diode emulation and adaptive frequency modes are disabled for these efficiency measurements.
90
EFFICIENCY (%)
88
86
84
82
80
78
76
74
0
2
4
6
8
10
OUTPUT CURRENT (A)
12
14
16
FIGURE 9. EFFICIENCY, VIN = 12V, VOUT = 1.2V
Ramp-up/Ramp-down Characteristics
1.4
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
-0.2
0
1.2
1.0
0.8
0.6
0.4
0.2
0
-0.2
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
TIME (s)
0
FIGURE 10. RAMP UP
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
TIME (s)
FIGURE 11. RAMP DOWN
Dynamic Load Response
0.005
0.030
0.025
0
VOUT (V)
0.020
VOUT (V)
-0.005
-0.010
0.015
0.010
0.005
0
-0.015
-0.005
-0.020
0
0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20
TIME (µs)
FIGURE 12. DYNAMIC RESPONSE, 7A TO 15A LOAD
STEP
13
-0.010
0
0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20
TIME (µs)
FIGURE 13. DYNAMIC RESPONSE, 15A TO 7A LOAD
STEP
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Application Note 1517
References
ZL2008 Data Sheet, Zilker Labs, Inc., 2008.
AN2033 – PMBus™ Command Set, Zilker Labs, Inc., 2008.
Ordering Information
ORDERABLE
PART NUMBER
ZL2008EVAL1Z
DESCRIPTION
ZL2008 Evaluation Kit (EVB, USB Adapter, Cable, Software)
Revision History
DATE
REV. #
DESCRIPTION
March 2010
AN1517.1
In “Target Specifications” on page 1, changed “Dynamic response: ±2.5%” to
"Dynamic response: ±3%"
December 2009
AN1517.0
Initial release
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the
reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
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