Texas Instruments LM63625QDRREVM User manual

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LM63625QDRREVM EVM User’s Guide
User's Guide
SNVU702–February 2020
LM63625QDRREVM EVM User’s Guide
The Texas Instruments LM63625QDRREVM evaluation module (EVM) helps designers evaluate the
operation and performance of the LM63625-Q1 buck regulator. The LM63625-Q1 is a family of easy-to-
use synchronous step-down DC/DC converters capable of driving up to 2.5 A of load current from an input
voltage of 3.5 V to 36 V. The LM63625-Q1 features a selectable output voltage of 3.3 V or 5 V and a
switching frequency of 2.1 MHz. See the LM636x5-Q1 3.5-V to 36-V, 1.5-A, and 2.5-A Automotive Step-
down Voltage Converter Data Sheet for additional features, detailed description, and available options.
The EVM options are found in Table 1.
Table 1. Device and Package Configurations
EVM DEVICE OUTPUT
CURRENT SWITCHING FREQUENCY PACKAGE
LM63625QDRREVM LM63625DQDRRQ1 2.5 A 2.1 MHz DRR0012
(WSON)
Figure 1. LM63625QDRREVM Board Image
Contents
1 Setup .......................................................................................................................... 3
2 Operation ..................................................................................................................... 6
3 Performance Curves ........................................................................................................ 6
4 Schematic..................................................................................................................... 7
5 Board Layout ................................................................................................................. 8
6 Bill of Materials ............................................................................................................. 11
List of Figures
1 LM63625QDRREVM Board Image........................................................................................ 1
2 EVM Board Connections.................................................................................................... 3
3 EVM Card Edge Connections.............................................................................................. 4

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LM63625QDRREVM EVM User’s Guide
4 Jumper Locations............................................................................................................ 4
5 FRA Setup.................................................................................................................... 5
6 Efficiency AUTO Mode, VOUT = 3.3 V, fSW = 2100 KHz.................................................................. 6
7 Efficiency Without Input Filter AUTO Mode, VOUT = 5 V, fSW = 2100 KHz............................................. 6
8 LM63625EVM Schematic................................................................................................... 7
9 Top View of EVM ............................................................................................................ 8
10 Bottom View of EVM ........................................................................................................ 8
11 EVM Top Copper Layer..................................................................................................... 9
12 EVM Mid Layer One......................................................................................................... 9
13 EVM Mid Layer Two ....................................................................................................... 10
14 EVM Bottom Copper Layer ............................................................................................... 10
List of Tables
1 Device and Package Configurations ...................................................................................... 1
2 BOM for LM63625EVM.................................................................................................... 11
Trademarks
All trademarks are the property of their respective owners.

LOAD
INPUT
POWER
SUPPLY
DMM
(+)
(-)
(+)
(-)
(-)
(+)
DMM
(+)
(-)
Input
Voltage
Ouput
Voltage
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LM63625QDRREVM EVM User’s Guide
1 Setup
This section describes the test points and connectors on the EVM and how to properly connect, set up,
and use the LM63625QDRREVM. Either the banana jacks on the top of the board or the card edge
connector can be used for connections. See Figure 2 for the top of board connections and Figure 3 for the
card edge connections. See the LM636x5-Q1 3.5-V to 36-V, 1.5-A, and 2.5-A Automotive Step-down
Voltage Converter Data Sheet for details. The following lists the functions of the connections:
VINEMI— Input supply to EVM. Connect to a suitable input supply.
GND— System ground
VOUT— Output of EVM. Connect to desired load.
VOS— Output voltage sense connection (do not use for power; sense only)
VIS— Input voltage sense connection (do not use for power; sense only)
GNDS— Ground sense point for analog measurements (do not use for power; sense only)
Figure 2. EVM Board Connections

VOUT Selection
Jumper Mode Selection
Jumper
Enable
Jumper
GND VOUT
GNDS
VOS
TOP FRONT
BOTTOM FRONT
VIS
VINEMI
INPUT
SUPPLY LOAD
(+) (-) (-) (+)
(+)
(-)
DMM
DMM
(-)(+)
(+) (-)
CM Choke
Input *
* = Optional Connections
Input
Voltage
Output
Voltage
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Figure 3. EVM Card Edge Connections
1.1 Jumpers
See Figure 4 for jumper locations.
VSEL— This jumper allows output voltage selection of either 3.3 V or 5 V. See the Section 2 for details.
MODE— This jumper allows the selection of either AUTO mode or FPWM mode. In addition, by removing
this jumper and supplying a clock signal to the SYNC/MODE test point, the device can by
synchronized to an external clock.
EN— This jumper turns the device on or off. In addition, by removing this jumper and supplying a signal
to the EN test point, the device can be controlled externally.
Figure 4. Jumper Locations

B
Signal
Injection
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network analyzer
^_/v‰µšš}
network analyzer
A
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1.2 Test Points
•VINEMI - Input supply to EVM. Connect to a suitable input supply.
•GND - System power ground
•VOUT - Power output of EVM. Connect to desired load.
•VOS - Output voltage sense connection. Connect to DMM.
•VINS - Input voltage sense connection. Connect to DMM.
•GNDS - Ground sense point for analog measurements. Connect to DMM.
•EN - Connected to the EN input of the device
•RESET - Connected to the RESET pin of the IC. It is used as a flag output. The reset function can be
monitored at this test point. Pull-up resistor, RPU, must be populated. A typical value for pullup resistor
is 100 kΩ.
•SYNC/MODE - Connected to the SYNC/MODE pin of the IC.
•VCC - Connected to the VCC output of the device. Can be used for logic level pullups, if needed.
•OPEN PADS - Connections for frequency response analyzer (on bottom of board) to take Bode plots.
See Figure 5 for details of connections.
Figure 5. FRA Setup

Output Current (A)
Efficiency (%)
0.001 0.01 0.1 1 55
40
45
50
55
60
65
70
75
80
85
90
95
100
DRR_
8V
13.5V
18V
24V
Output Current (A)
Efficiency (%)
0.001 0.01 0.1 1 55
40
45
50
55
60
65
70
75
80
85
90
95
100
DRR_
8V
13.5V
18V
24V
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LM63625QDRREVM EVM User’s Guide
2 Operation
Once the above connections are made and the appropriate jumpers are set, the EVM is ready to use.
The output voltage of the EVM can be selected by the VSEL jumper to either 3.3 V or 5 V. EN must be
cycled when the jumper is changed, in order for the selection to be programmed. Other values of output
voltage can be set by removing the VSEL jumper and populating Radj (on bottom) with a 10 kΩ. Values
for RFBT and RFBB are then selected and populated in the designated locations. See the LM636x5-Q1 3.5-V
to 36-V, 1.5-A, and 2.5-A Automotive Step-down Voltage Converter Data Sheet for more information.
The switching mode of the EVM can be changed by using the SYNC/MODE jumper; this selection can be
made "on-the-fly".
To use the RESET function, a pullup resistor is required. A place for this resistor is provided on the bottom
of the PCB (RPU). Values of 10 kΩto 100 kΩare appropriate. Be sure to limit the voltage on this pullup to
less than the specified Abs max for this pin.
Some components in the EMI filter are not populated. The user is free to experiment with different EMI
filter components as desired.
Loop gain measurements (Bode plots) can be made using the setup shown in Figure 5.
The EVM has been designed for maximum flexibility regarding component selection. This allows the user
to place preferred components such as the inductor, the capacitors, or both, on the board and test the
performance of the regulator. This way the power supply system can be tested before committing the
design to production.
3 Performance Curves
Figure 6. Efficiency
AUTO Mode, VOUT = 3.3 V, fSW = 2100 KHz Figure 7. Efficiency Without Input Filter AUTO Mode, VOUT = 5 V, fSW = 2100 KHz

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4 Schematic
Figure 8. LM63625EVM Schematic

CAUTION
Caution Hot surface.
Contact may cause burns.
Do not touch.
Board Layout www.ti.com
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5 Board Layout
Figure 9. Top View of EVM
Figure 10. Bottom View of EVM

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Figure 11. EVM Top Copper Layer
Figure 12. EVM Mid Layer One

Board Layout www.ti.com
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Figure 13. EVM Mid Layer Two
Figure 14. EVM Bottom Copper Layer