7
Rinc
D1
L1
Rfbt
VIN
U1
SW
FB
LMR10530YSD
SW
8
VOUT
Rfbb
Cff
Cinc
Co2
Ren
Co1
9
5
4
6
10
2
1
11
3
SW
SW
NC
PGND
SGND
DAP
VINC
EN
EN
VIND
VIND
GND
1 Introduction
The LMR10530 evaluation module is designed to provide the power supply design engineer with a fully
functional regulator design using the LMR10530 3MHz switching regulator in an WSON-10 package. The
evaluation module is configured to provide an output of 1.2V at up to 3A from an input voltage range of 3V
to 5.5V.
The printed circuit board consists of 4 layers of copper on FR4 material. The middle layers are solid
ground layers with the first middle layer having a small polygon cut out for the VINnode. The intermediate
ground layer helps in minimizing the AC current loop. The LMR10530 is thermally tied to the other layers
by thermal vias directly underneath the device. This user's guide contains the evaluation module
schematic, a quick setup procedure, and a Bill-of-Materials (BOM). For complete circuit design
information, see LMR10530 SIMPLE SWITCHER 5.5Vin, 3.0A Step-Down Voltage Regulator in WSON-10
(SNVS814).
The module has a Cffcapacitor footprint reserved for applications requiring higher V
helps to minimize the output voltage overshoot during sluggish startup. For suggested cap values, see the
LMR10530 datasheet (SNVS814). The module also has a reserved footprint for an additional output cap,
Co2, for certain applications requiring more capacitance.
User's Guide
SNVU192A–October 2012–Revised April 2013
AN-2280 LMR10530 Evaluation Module
. The Cffcap also
OUT
The performance of the evaluation board is:
• Input Range: 3 to 5.5V
• Output Voltage: 1.2V
• Output Current: 0 to 3A
• Frequency of Operation: 3000 kHz
• Board Size: 2.016 × 1.08 inches (51.2 × 27.43 mm)
2 Evaluation Board Schematic
Figure 1. LMR10530 Evaluation Module Schematic
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Powering and Loading Considerations
3 Powering and Loading Considerations
Read this entire section prior to attempting to power the evaluation board.
3.1 Quick Start Procedure
Step 1: Set the bench power supply current limit to 3A. Set the power supply voltage to 4V. Turn off the
power supply output. Connect the power supply to the LMR10530 demo board. Positive connection to V
and negative connection to GND.
Step 2: Connect a load, as high as 3A, to the V
connection to GND.
Step 3: The EN pin should be left open for normal operation.
Step 4: Turn on the bench power supply with no load applied to the LMR10530. The V
regulation at a nominal 1.2V output.
Step 5: Slowly increase the load while monitoring the output voltage, V
the load is increased up to 3 Amps. The LMR10530 is designed to skip some pulses at very light loads to
maintain output voltage regulation. Depending on load levels, the circuit may operate in either
discontinuous or continuous conduction mode.
Step 6: Slowly sweep the input voltage from 3 to 5.5V, V
1.2V output.
3.2 Starting Up
terminal. Positive connection to V
OUT
should remain in regulation as
OUT
should remain in regulation with a nominal
OUT
and negative
OUT
would be in
OUT
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IN
By default, VINC is connected to VINthrough a low pass filter to remove any high frequency noise present
at the input. EN is connected to VINC through a 100kΩ resistor. A separate logic signal at the EN terminal
can be used, if startup and shutdown need to be controlled. The EN pin is tied to VINto simplify start-up.
The pull-up resistor allows the power supply design engineer to toggle EN independently, if desired, and
observe the start-up behavior of the LMR10530.
3.3 Adjusting the Output Voltage
The output voltage is set using the following equation where R
GND, and R
V
OUT
The feedback voltage VFB is regulated at 0.60V typically.
Adjusting the output voltage will affect the performance of the LMR10530. In addition, output capacitors
might not be rated for the new output voltage. For more information, see LMR10530 SIMPLE SWITCHER
5.5Vin, 3.0A Step-Down Voltage Regulator in WSON-10 (SNVS814).
is connected between V
fbt
= VFB(1 + (R
)) (1)
fbt/Rfbb
OUT
and FB.
is connected between the FB pin and
fbb
2
AN-2280 LMR10530 Evaluation Module SNVU192A–October 2012–Revised April 2013
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Co
VOUT GND
Oscilloscope
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3.4 Typical Test Setup
Powering and Loading Considerations
Figure 2. Efficiency Measurements
SNVU192A–October 2012–Revised April 2013 AN-2280 LMR10530 Evaluation Module
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Figure 3. Voltage Ripple Measurements
3
Copyright © 2012–2013, Texas Instruments Incorporated
GND
EN
VIN SENSE+
SPARE
VOUT SENSE+
I I I I I I
I I I I I I
1 2 3 4 5 6
A B C D E F
VIN
VOUT
GND
Powering and Loading Considerations
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Figure 4. Edge Connector Schematic
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