ANALOG DEVICES LT7170-1-AZ Evaluation Board User Guide
- May 15, 2024
- Analog Devices
Table of Contents
Evaluation Board User Guide
EVAL-LT7170-1-AZ
20A, 16V Dual-Phase Silent Switcher Step-Down Regulator
with Digital Power System Management
General Description
Evaluation kit EVAL-LT7170-1-AZ is a dual-phase singleoutput monolithic DC/DC
synchronous step-down regulator with a 2.9V or 1.5V with EXTVCC to 16V input
range featuring LT®
7170-1. The output can
supply 20A continuous load current. The Silent Switcher® regulator structure
is incorporated into the LT7170-1 to minimize EMI and reduce PCB layout
sensitivity. It also integrates digital power system management functionality,
allowing for programmability and telemetry with a PMBus/I 2C compliant serial
interface. Refer to the LT7170-1 data sheet for more detailed information.
The EVAL-LT7170-1-AZ evaluation board is designed for 1.0V output with a
switching frequency set at 1MHz. The controlled on-time valley current-mode
control with 25ns typical minimum on-time enables a high switching frequency
at a low output voltage with excellent transient response in a small overall
solution size.
The EVAL-LT7170-1-AZ has EMI filters installed for improved conducted and
radiated EMI performances, which are shown in Figure 5. The red lines in
Figure 5 are CISPR32 limit for industrial application requirement. The figure
shows that the circuit passes the test with a wide margin.
The EVAL-LT7170-1-AZ powers up to default settings and produces power based on
the NVM configuration without the need for any serial bus communication. This
allows easy evaluation of the DC/DC converter. To fully explore the power
system management features of the part, download the GUI software LTpowerPlay®
onto the PC and use ADI’s I 2C/SMBus/PMBus dongle DC1613A to connect to the
board. LTpowerPlay allows the user to reconfigure the part on the fly, and
store the configuration in NVM, view telemetry of voltage, current,
temperature, and fault status. The NVM can be programmed up to three times.
GUI Download
The software can be downloaded from LTpowerPlay.
The LT7170-1 data sheet gives a complete description of the part, operation,
and application information. The data sheet must be read in conjunction with
this demo manual for EVAL-LT7170-1-AZ.
For more details and instructions of the LTpowerPlay, refer to LTpowerPlay GUI
for the LT7170-1 Quick Start Guide.
Performance Summary
Specifications are at T A = 25°C
PARAMETER| SYMBOL| CONDITIONS| MIN| TYP| MAX|
UNITS
---|---|---|---|---|---|---
Input Voltage Range| VIN| EXTVCC = 0V| 2.9| | 16| V
3V ≤ EXTVCC ≤ 5.5V| 1.5| | 16
Default Output Voltage| VOUT| | 1.0| V
Maximum Continuous Output Current| IOUT| | 20| A
Switching Frequency| fSW| | 0.925| 1| 1.075| MHz
Efficiency| Eff| VIN = 12V, IOUT = 10A| 87.6| %
Quick Start Procedure
The EVAL-LT7170-1-AZ is easy to set up to evaluate the performance of the
LT7170-1. See Figure 1 for proper measurement equipment setup, and follow the
procedure below:
NOTE: When measuring the input or output voltage ripple, care must be
taken to avoid a long ground lead on the oscilloscope probe. See Figure 2 for
the proper scope technique.
-
Set an input power supply that is capable of 16V/10A. Then turn off the supply.
-
With power off, connect the supply to the input terminals VEMI and GND. Set the default jumper position: SW1: ON.
-
Turn on the power at the input.
NOTE: Make sure that the input voltage never exceeds 16V. -
Check for the proper output voltages of 1.0V ±0.25% (0.997V~1.003V). Turn off the power at the input.
-
Once the proper output voltage is established, connect variable loads capable of sinking 20A at 1.0V to the output terminals VOUT and GND. Set the current to 0A.
a. If efficiency measurements are desired, ammeters can be put in series with the output load to measure the EVAL- LT7170-1-AZ’s output current and in series with the power supply to measure the input current.
b. Voltmeters can be placed across the output terminals (VSENSE+, VSENSE-) to get accurate output voltage measurements.
c. Voltmeters can be placed across the input terminals (VIN_SENSE, GND) to get accurate input voltage measurements.
d. To achieve the best efficiency and accuracy, remove R11/R16 and populate R21/R22 only on the bottom layer of the board. -
Turn on the power at the input.
NOTE: If there is no output, temporarily disconnect the load to make sure that the load is not set too high. -
Once the proper output voltages are established again, adjust the load and/or input within the operating range and observe the output voltage regulation, ripple voltage, efficiency, and other desired parameters.
-
Connect the dongle and control the output voltages from the GUI. See the LTpowerPlay GUI for the LT7170-1 Quick Start Guide for details.
NOTE: When measuring the output or input voltage ripple, do not use the
long ground lead on the oscilloscope probe. See Figure 2 for the proper scope
probe technique. Short, stiff leads need to be soldered to the (+) and (-)
terminals of an output capacitor. The probe’s ground ring needs to touch the
(-) lead, and the probe tip needs to touch the (+) lead.
Connecting a PC to EVAL-LT7170-1-AZ
Use a PC to reconfigure the power management features of the LT7170-1, such as
VOUT, current limit, switching frequency, OV/UV limits, control loop
compensation, temperature fault limits, sequencing parameters, the fault log,
fault responses, and other functionalities. The DC1613A dongle may be plugged
in when a VIN is present. Figure 3 shows a demo setup of connecting a PC to
EVAL-LT7170-1-AZ.
Typical Performance Characteristics
LTpowerPlay Software GUI
LTpowerPlay is a powerful, Windows® -based development environment supporting
Analog Devices’ Digital Power System Management (DPSM) ICs and μModule®
regulators. The software supports a variety of different tasks. Use
LTpowerPlay to evaluate Analog Devices’ ICs by connecting to an evaluation
board system. LTpowerPlay can also be used in offline mode (with no hardware
present) in order to build a multichip configuration file that can be saved
and reloaded at a later time. LTpowerPlay provides unprecedented diagnostic
and debug features. It becomes a valuable 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. LTpowerPlay utilizes the DC1613A USB-to-
SMBus controller to communicate with one of many potential demo systems 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.
The LTpowerPlay software can be downloaded from LTpowerPlay | Analog
Devices.
To access technical support documents for Analog Devices’ Digital Power
Products, visit the LTpowerPlay Help menu. Online help is also available
through LTpowerPlay. 
LTpowerPlay Quick Start Procedure
The following procedure describes how to use LTpowerPlay to monitor and change the settings of LT7170-1.
- Download and install the LTPowerPlay GUI: LTpowerPlay | Analog Devices.
- Launch the LTpowerPlay GUI.
- The GUI should automatically identify the EVAL-LT7170-1-AZ. The system tree on the left-hand side should look like the image below.
- A green message box shows for a few seconds in the lower left-hand corner, confirming that LT7170-1 is communicating:
- In the toolbar, click the R (RAM to PC) icon to read the RAM from the LT7170-1. This reads the configuration from the RAM of the LT7170-1 and loads it into the GUI.
- To change the output voltage to a different value, like 1.5V, in the Config tab, type in 1.5 in the VOUT_COMMAND box under the Voltage tab, as shown below.
- Then, click the W (PC to RAM) icon to write the register values to the LT7170-1. After finishing this step, the output voltage changes to 1.5V.
- If the write is successful, the following message will appear.
- To save the changes to NVM in the tool bar, click the RAM to NVM button.
- Save the evaluation board configuration to a (*.proj) file. Click the Save icon and save the file with a new name.
Bill of Materials
ITEM| QTY| REFERENCE| PART DESCRIPTION|
MANUFACTURER/PART NUMBER
---|---|---|---|---
REQUIRED CIRCUIT COMPONNENTS
1| 4| C1, C2, C5, C14| CAP., 0.1µF, X6S, 25V, 10%, 0201| TAIYO YUDEN,
TMK063C6104KP-F
2| 1| C3| CAP., 4.7µF, X6S, 25V, 10%, 0603| MURATA, GRM188C81E475KE11D
3| 2| C6, C8| CAP., 10µF, X6S, 10V, 10%, 0603| MURATA, ZRB18AC81A106KE01L
4| 1| C7| CAP., 1µF, X7S, 10V, 10%, 0402| MURATA, GRM155C71A105KE11D
5| 2| C15, C16| CAP., 10µF, X7S, 4V, 20%, 0603| TDK, C1608X7S0G106M080AB
6| 1| C19| CAP., 1µF, X7S, 10V, 10%, 0402| MURATA, GCM155C71A105KE38D
7| 4| C17, C29, C36, C37| CAP., 100µF, X6S, 4V, 20%, 0805| MURATA,
GRM21BC80G107ME15L
8| 2| L1, L2| IND., 0.40µH, 22.5A, 32.8mΩ| COILCRAFT, XGL4030-401MEC
9| 1| U1| IC, 20A, 16V REGULATOR, LQFN-24| ANALOG DEVICES, LT7170RV- 1#TRPBF
ADDITIONAL EVALUATION BOARD CIRCUIT COMPONENTS
1| 1| C4| CAP., 100µF, ALUM, 35V, 20%| PANASONIC, EEHZK1V101XP
2| 0| C9, C10| CAP., OPTION, 7343|
3| 0| C11| CAP., OPTION, 0603|
4| 6| C12, C13, C22, C24, C30, C33| CAP., 10µF, X7S, 25V, 10%, 0805| MURATA,
GRM21BC71E106KE11L
5| 3| C18, C20, C21| CAP., 4.7µF, X5R, 25V, 10%, 0603| MURATA,
GRM188R61E475KE15D
7| 1| C23| CAP., 1µF, X5R, 25V, 10%, 0603| AVX, 06033D105KAT2A
8| 4| C25, C26, C27, C28| CAP., 1µF, X5R, 25V, 10%, 0402| MURATA,
GRM155R61E105KA12D
9| 1| C31| CAP., 0.1µF, X7R, 10V, 20%, 0603| AVX, 0603ZC104MAT2A
10| 3| C32, C34, C35| CAP., 1µF, X7R, 6.3V, 10%, 0402| MURATA,
GRM155R70J105KA12D
11| 1| C38| CAP., 1µF, X7R, 50V, 10%, 0603| AVX, 06035C105KAT2A
12| 2| C39, C40| CAP., 0.01µF, X7R,25V, 10%, 0603| AVX, 06033C103K4Z2A
13| 1| C41| CAP., 10µF, X7R, 10V, 10%, 0805| AVX, 0805ZC106KAT2A
14| 1| C42| CAP., 1500pF, X7R, 25V, 10%, 0603| AVX, 06033C152KAT2A
15| 1| D1| LED, GREEN, DIFFUSED, 0603| BROADCOM INC., HSMG-C190
16| 1| D2| LED, RED, DIFFUSED, 0603| BROADCOM INC., HSMH-C190
17| 1| FB1| FERRITE BEAD, 100Ω@100MHz, 1812| WURTH ELEKTRONIK, 74279226101
18| 1| L3| IND., 0.47µH, 6.8A, 14mΩ| WURTH ELEKTRONIK, 744373240047
19| 1| Q1| MOSFET, N-CH, 25V, 70A, Power-SO8| NEXPERIA, PSMN5R4-25YLDX
20| 1| Q2| MOSFET, N-CH, 60V, 300mA, SOT-23-3| VISHAY, 2N7002K-T1-GE3
21| 4| R2, R5, R8, R9| RES., 10kΩ, 1%, 1/10W, 0603| VISHAY, CRCW060310K0FKEA
22| 2| R3, R12| RES., 866Ω, 1%, 1/10W, 0603| VISHAY, CRCW0603866RFKEA
---|---|---|---|---
23| 0| R4, R18| RES., OPTION, 0603|
24| 2| R6, R13| RES., 4.99kΩ, 1%, 1/10W, 0603| PANASONIC, ERJ3EKF4991V
25| 1| R7| RES., 10mΩ, 1%, 3W, 6.3 X3.1mm| SUSUMU, KRL6432E-C-R010-F-T1
26| 1| R10| RES., 49.9Ω, 1%, 1/10W, 0603| PANASONIC, ERJ3EKF49R9V
27| 3| R11, R16, R20| RES., 0Ω, 1/10W, 0603| VISHAY, CRCW06030000Z0EA
28| 1| R19| RES., 36.5kΩ, 1%, 1/10W, 0603| YAGEO RC0603FR‐0736K5L
29| 0| R21, R22| RES., OPTION, 0603|
30| 1| R14| RES., 1MΩ, 1%, 1/10W, 0603,| NIC, NRC06F1004TRF
31| 1| U2| IC, EEPROM, 2Kb (256×8), TSSOP-8| MICROCHIP, 24LC025-I/ST
32| 1| U3| IC, 2.6A, 2.5V-5.5V IDEAL DIO, 10DFN| ANALOG DEVICES,
LTC4413EDD#PBF
33| 1| U4| IC, 200mA LDO, MSOP-8| ANALOG DEVICES, LT3063EMS8E- 3.3#PBF
HARDWARE: FOR EVALUATION BOARD ONLY
1| 5| E1, E2, E3, E4, E5| TEST POINT, TURRET, 0.064″| MILL-MAX,
2308-2-00-80-00-00-07-0
2| 8| E6, E7, E8, E9, E10, E11, E12, E13| TEST POINT, TURRET, 0.094″| MILL-
MAX, 2501-2-00-80-00-00-07-0
3| 4| J1, J2, J3, J4| BANANA JACK, FEMALE| KEYSTONE, 575-4
4| 1| J5| CONN., HDR, MALE, 2×6,2mm| AMPHENOL, 98414-G06-12ULF
5| 2| J6, J7| CONN., BNC, 50Ω| AMPHENOL RF, 112404
6| 1| JP1| CONN., HDR, MALE, 1×3, 2mm| WURTH ELEKTRONIK, 62000311121
7| 4| MP1, MP2, MP3, MP4| STANDOFF, NYLON, SNAP-ON, 0.50″| KEYSTONE, 8833
8| 1| SW1| SWITCH, SLIDE, DPDT, 0.3A, 6VDC, PTH| C&K, JS202011CQN
9| 1| XJP1| CONN., SHUNT, FEMALE, 2-POS, 2mm| WURTH ELEKTRONIK, 60800213421
Schematic Diagram
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