DEMO MANUAL DC2739A
LTC2972
4-Channel PMBus Power System Manager
with LTM4644 Quad 4A Power Supply
DESCRIPTION
The DC2739A is a two-board demonstration system
consisting of the DC2675A and DC2363A. The DC2675A
contains all the circuitry needed to use two
LTC
®
2972
Power System Managers to control four power supplies.
The DC2363A contains four power supplies (LTM
®
4644-1
quad 4A µModule
®
regulator) which are configured to be
controlled by the two LTC2972 devices. The DC2363A and
DC2675A demo boards together provide a sophisticated
4-channel digitally programmable power supply system.
The LTC2972 is a 2-channel I
2
C/SMBus/PMBus Power
System Manager that features accurate input current and
energy measurement. The device monitors input current
and input voltage, and calculates input power and energy.
The DC2675A demonstrates the ability of the LTC2972
to sequence, trim, margin, supervise, monitor, and log
faults for four power supplies. The LTC2972 monitors
each channel’s output voltage and output current and also
monitors its own internal die temperature.
The DC2363A is a single circuit board that contains four
independent power supply rails. The board employs a
single LTM4644 4-channel 4A DC/DC regulator. The board
is pre-configured with 1.0V, 1.5V, 2.5V, and 3.3V supply
rails and may be reconfigured with feedback resistors.
The LTpowerPlay
®
graphical user interface (GUI) supports
this demonstration system and enables complete control of
all the features of the LTC2972. Together, the LTpowerPlay
software and DC2739A hardware system create a powerful
development environment for designing and testing configu-
ration settings of the LTC2972. LTpowerPlay stores these
settings in the LTC2972’s internal EEPROM or in a project
file. The software displays all of the configuration settings
and real time measurements from the Power System Man-
agement IC. Telemetry allows easy access and decoding of
the fault log created by the LTC2972. The board comes pre-
programmed with the EEPROM values appropriate for the
four power supply rails on the DC2739A. Just plug and play!
Multiple DC2739A boards can be cascaded together to form
a high channel count power supply (see Multi-Board Arrays).
This cascaded configuration demonstrates features of the
ADI Power System Management ICs which enable timing
and fault information that is shared across multiple Power
System Management ICs. The user can configure up to eight
DC2739A boards, thereby controlling up to 32 separate
power supply rails. Larger board arrays can be built using
programmable I
2
C base addresses or bus segmentation.
Order preprogrammed devices from Linear Express using
LTpowerPlay.
The following items are required:
• +12VDC Power Supply
• USB-to-I
2
C/SMBus/PMBus Controller (DC1613)
• LTpowerPlay Software
DC2739A Features
• Sequence, Trim, Margin, and Supervise Four Power
Supplies
• Manage Faults, Monitor Telemetry, and Create Fault
Logs
• PMBus Compliant Command Set
• Supported by LTpowerPlay GUI
• Margin or Trim Supplies to 0.25% Accuracy
• Four I
OUT
and One I
IN
Monitor
• Input Power Measurement and Energy Accumulation
• Fast OV/UV Supervisors per Channel
• Multichannel Fault Management
• Automatic Fault Logging to Internal EEPROM
• Operates Autonomously without Additional Software
• Monitors: Voltage, Current, Power, Temperature
• 4-Channel Time-Based Output Sequencer
• I
2
C/SMBus Serial Interface
• Powered from 4.5V to 14V
Design files for this circuit board are available at
http://www.analog.com/DC2739A
All registered trademarks and trademarks are the property of their respective owners.
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1
DEMO MANUAL DC2739A
PERFORMANCE SUMMARY
PARAMETER
V
PWR
Supply Input Operating Range
V
DD33
Supply Input Operating Range
ADC Total Unadjusted Error
ADC Voltage Sensing Input Range
ADC Current Sensing Input Range
ADC Voltage Sensing Resolution
ADC Current Sense Resolution
Differential Current Sense Voltage
0V ≤ V
IN_ADC
≤ 6V
0mV < |V
IN_ADC
| < 16mV
16mV < |V
IN_ADC
| < 32mV
32mV < |V
IN_ADC
| < 63.9mV
63.9mV < |V
IN_ADC
| < 127.9mV
127.9mV < |V
IN_ADC
|
Buffer Gain Setting 0
Buffer Gain Setting 1
V
SENSEP[n]
Low Resolution
High Resolution
0V to 3.8V Range: 4.096/1024
0V to 6V Range: 8.192/1024
2V < V
IN_VS
< 6V, Low Resolution Mode
1.5V < V
IN_VS
< 3.8V, High Resolution Mode
0.8V < V
IN_VS
< 1.5V, High Resolution Mode
10
V
IN
≥ 1V
–0.1
–170
122
15.6
31.25
62.5
125
250
10
1.38
2.65
±1
0
0
4
8
±1.25
±1.0
±1.5
400
6
3.8
Specifications are at T
A
= 25°C
CONDITIONS
MIN
4.5
3.13
±0.25
6
170
TYP
MAX
15
3.47
UNITS
V
V
%
V
mV
µV/LSB
µV/LSB
µV/LSB
µV/LSB
µV/LSB
µV/LSB
Bits
V
V
°C
V
V
mV/LSB
mV/LSB
%
%
%
kHz
DAC Resolution
DAC Full-Scale Output Voltage
Temperature Sensor TUE
Voltage Supervisor Input Voltage Range (Programmable)
Voltage Supervisor Sensing Resolution
Voltage Supervisor Total Unadjusted Error (TUE)
I
2
C Serial Clock Frequency
Table 1. DC2363 System Specifications
NOMINAL UNTRIMMED V
OUT
CH0
CH1
CH2
CH3
Notes:
• Load current <4A is recommended.
• Output voltages can be margined by ±15% from nominal with the default resistor values on the DC2363A. These values can be easily changed. See
section Changing Nominal Output Voltages. Use the LTC2972 Resistor Selection Tool which is accessed from LTpowerPlay.
1.0V ±1.5%
1.5V ±1.5%
2.5V ±1.5%
3.3V ±1.5%
TOP FEEDBACK RESISTOR
60.4k
60.4k
60.4k
60.4k
BOTTOM FEEDBACK RESISTOR
90.9k
40.2k
19.1k
13.3k
R
DAC
237k
158k
95.3k
73.2k
MARGIN RANGE
±15%
±15%
±15%
±15%
2
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DEMO MANUAL DC2739A
GLOSSARY OF TERMS
The following list contain terms used throughout the document.
Channel:
The collection of functions that monitor, supervise, and trim a given power supply rail.
EEPROM:
Non-volatile memory (NVM) storage used to retain data after power is removed.
Margin:
Term used typically in board level testing that increases/decreases the output voltage to look for sensitivity/
marginality problems.
Monitor:
The act of measuring voltage, current, and temperature readings.
NVM:
Nonvolatile memory, see EEPROM.
OV:
Overvoltage, the result of a voltage comparison that a pin voltage is above a programmable threshold voltage.
PMBus:
An industry standard power management protocol with a fully defined command language that facilitates
communication with power converters and other devices in a power system.
Rail:
The final output voltage that the LTC2972 supervises.
Supervise:
The act of quickly responding (compared to a fault setting) to a voltage and current condition that is com-
pared to preprogrammed values.
Trim:
The act of adjusting the final output voltage. A servo loop trims the output voltage.
UV:
Undervoltage, the result of a voltage comparison that a pin voltage is below a programmable threshold voltage.
WHAT THIS DEMO SYSTEM CAN DO
• Prototype your system by modifying: nominal output
voltages, range and resolution of margining, sequenc-
ing, OV/UV limits, and OC limits.
• Create your own configuration: store in the LTC2972
EEPROM or save to a project file. Order preprogrammed
parts.
• Test fault scenarios. Short outputs to ground, and
observe system response and faults.
Demo System Hardware
Hardware required:
1. DC2739A = DC2363A plus DC2675A
2. PC and USB cable
3. 12V, >1A power supply
4. USB to I
2
C/SMBus/PMBus Controller
Figure 1. DC2739A Demo Setup
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DEMO MANUAL DC2739A
LTPOWERPLAY GUI SOFTWARE
LTpowerPlay is a powerful Windows-based development
environment that supports Analog Devices Power System
Management ICs with EEPROM, including the LTC2972
4-channel Power System Manager. The software supports
a variety of different tasks. You can use LTpowerPlay to
evaluate Analog Devices ICs by connecting to a demo
board system. LTpowerPlay features an offline mode to
build a multi-chip configuration file for later use with
hardware. LTpowerPlay provides unprecedented system
level diagnostic and debug features. It becomes a valu-
able diagnostic tool during board bring-up to program or
tweak the power management scheme in a system or to
diagnose power issues when bringing up rails. LTpower-
Play utilizes the DC1613 I
2
C/SMBus/PMBus controller to
communicate with one of many potential targets, includ-
ing the DC2739A demo system or a customer board. The
software also provides an automatic update feature to
keep the software current with the latest set of device
drivers and documentation. Download the software from
LTpowerPlay.
Select “Help, View Online Help” from the LTpowerPlay
menu to access technical documents.
Figure 2. Screenshot of the LTpowerPlay GUI
4
UG-1418 Rev 0
DEMO MANUAL DC2739A
QUICK START PROCEDURE
The following procedure describes how to set up a
DC2739A demo system.
1. Download and install the
LTpowerPlay
GUI:
2. Remove the board from the ESD protective bag and
place it on a level surface. Connect the DC1613 I
2
C/
SMBus/PMBus Controller to the DC2675A board using
the 12-pin ribbon cable.
3. Confirm that all jumpers and switches are set as follows:
a. The CONTROL switches are set to the RUN position.
b. On the DC2675A board, set U0 ASEL jumpers to
LOW (address 0x5C), set U1 ASEL1 to LOW and
ASEL0 to FLOAT (address 0x5E), and VDDIO jumper
to 3.3V.
c. On DC2363A board, set PRE-LOAD jumpers to ON,
and TRACK jumpers to SS.
4. Plug the USB-to-I
2
C/SMBus/PMBus Controller into a
USB port on your PC. Devices U0 and U1 should power
up with the LED1 illuminated green, and the four PG
LEDs should be illuminated red.
5. Connect a +12VDC power supply with >1A capacity to the
V
IN
input jack of the DC2363A board. The four outputs
will power up and the green LEDs will illuminate. The
PG LEDs on the DC2675A board should be illuminated
blue, indicating a logic ‘1’ on the PG pins.
6. Launch the LTpowerPlay GUI.
a. The GUI automatically identifies the DC2675A and
builds a system tree for each I
2
C device. The system
tree on the left hand side will look like this:
Figure 3. Connecting DC2363A/DC2675A Boards and the DC1613 USB to I
2
C/SMBus/PMBus Controller
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