Texas Instruments TPS562231EVM User manual

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TPS562231EVM 2-A, Synchronous step-down converter evaluation module
User's Guide
SLUUBZ4–February 2019
TPS562231EVM 2-A, Synchronous step-down converter
evaluation module
This user's guide contains information for the TPS562231 as well as support documentation for the
TPS562231EVM evaluation module. Included are the performance specifications, schematic, and the bill
of materials of the TPS562231EVM.
Contents
1 Introduction ................................................................................................................... 2
2 Performance Characteristics Summary................................................................................... 2
3 Modifications.................................................................................................................. 3
4 Test Setup and Results..................................................................................................... 4
5 Board Layout ................................................................................................................. 8
6 Schematic, Bill of Materials, and Reference............................................................................ 10
List of Figures
1 TPS562231EVM Efficiency................................................................................................. 5
2 TPS562231EVM Load Transient Response ............................................................................. 5
3 TPS562231EVM Output Voltage Ripple in CCM........................................................................ 6
4 TPS562231EVM Output Voltage Ripple in DCM........................................................................ 6
5 TPS562231EVM Output Voltage Ripple on No-load.................................................................... 7
6 Top Assembly................................................................................................................ 8
7 Top Layer..................................................................................................................... 9
8 Bottom Layer................................................................................................................. 9
9 TPS562231EVM Schematic Diagram ................................................................................... 10
List of Tables
1 Input Voltage and Output Current Summary............................................................................. 2
2 TPS562231EVM Performance Characteristics Summary.............................................................. 2
3 Output Voltages.............................................................................................................. 3
4 Connection and Test Points................................................................................................ 4
5 List of Materials............................................................................................................. 11
Trademarks
D-CAP3 is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.

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1 Introduction
The TPS562231 is a single, adaptive on-time, D-CAP3™ mode, synchronous buck converter requiring a
very low external component count. The proprietary D-CAP3 mode control supports low ESR output
capacitors such as specialty polymer capacitors and multi-layer ceramic capacitors without complex
external compensation circuits. The fast transient response of D-CAP3 mode control can reduce the
output capacitance required to meet a specific level of performance. The switching frequency is internally
set at a nominal 850 kHz and enters Advanced Eco-mode in light load conditions. The high-side and low-
side switching MOSFETs are incorporated inside the TPS562231 package along with the gate-drive
circuitry. The low drain-to-source on resistance of the MOSFETs allows the TPS562231 to achieve high
efficiencies and helps keep the junction temperature low at high output currents. The TPS562231 dc/dc
synchronous converter is designed to provide up to a 2-A output from an input voltage source of 4.5 V to
17 V. The output voltage range is from 0.6 V to 7 V. Rated input voltage and output current ranges for the
evaluation module are given in Table 1.
The TPS562231EVM evaluation module (EVM) is a single, synchronous buck converter providing 3.3 V at
2 A from 4.5-V to 17-V input. This user’s guide describes the TPS562231EVM performance.
Table 1. Input Voltage and Output Current Summary
EVM INPUT VOLTAGE RANGE OUTPUT CURRENT RANGE
TPS562231EVM VIN = 4.5 V to 17 V 0 A to 2 A
2 Performance Characteristics Summary
A summary of the TPS562231EVM performance specifications is provided in Table 2. Specifications are
given for an input voltage of VIN = 12 V and an output voltage of 3.3 V, unless otherwise noted. The
ambient temperature is 25°C for all measurement, unless otherwise noted.
Table 2. TPS562231EVM Performance Characteristics Summary
SPECIFICATIONS TEST CONDITIONS MIN TYP MAX UNIT
Input voltage range (VIN) 4.5 12 17 V
CH1
Output voltage 3.3 V
Operating frequency VIN = 12 V, IO= 2 A 850 kHz
Output current range 0 2 A
Over current limit VIN = 12 V, LO= 3.3 µH 2.8 A
Output ripple voltage VIN = 12 V, IO= 2 A 15 mVPP

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3 Modifications
These evaluation modules are designed to provide access to the features of the TPS562231. Some
modifications can be made to this module.
3.1 Output Voltage Setpoint
To change the output voltage of the EVMs, it is necessary to change the value of resistor R5. Changing
the value of R5 can change the output voltage above 0.6 V. The value of R5 for a specific output voltage
can be calculated using Equation 1.
(1)
Table 3 lists the R5 values for some common output voltages. Note that the values given in Table 3 are
standard values and not the exact value calculated using Table 3.
Table 3. Output Voltages
OUTPUT VOLTAGE
(V) R5 (kΩ)R6 (kΩ)
L1
(µH) C5 + C6 +C7
(µF)
Min Typ Max
1.0 6.65 10.0 1 1.5 4.7 20 - 68
1.05 7.5 10.0 1 1.5 4.7 20 - 68
1.2 10 10.0 1 1.5 4.7 20 - 68
1.5 15 10.0 1.5 2.2 4.7 20 - 68
1.8 20 10.0 1.5 2.2 4.7 20 - 68
2.5 31.6 10.0 2.2 3.3 4.7 20 - 68
3.3 45.3 10.0 2.2 3.3 4.7 20 - 68
5.0 73.2 10.0 3.3 4.7 4.7 20 - 68
6.5 98.3 10.0 3.3 4.7 4.7 20 - 68

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4 Test Setup and Results
This section describes how to properly connect, set up, and use the TPS562231EVM. The section also
includes test results typical for the evaluation modules and efficiency, output load regulation, output line
regulation, load transient response, output voltage ripple, input voltage ripple, start-up, and switching
frequency.
4.1 Input/Output Connections
The TPS562231EVM is provided with input/output connectors and test points as shown in Table 4. A
power supply capable of supplying 2 A must be connected to J1 through a pair of 20-AWG wires. The load
must be connected to J2 through a pair of 20-AWG wires. The maximum load current capability is 2 A.
Wire lengths must be minimized to reduce losses in the wires. Test point TP3 provides a place to monitor
the VIN input voltages with TP4 providing a convenient ground reference. TP9 is used to monitor the output
voltage with TP5 as the ground reference.
Table 4. Connection and Test Points
REFERENCE DESIGNATOR FUNCTION
J1 VIN (see Table 1 for VIN range)
J2 VOUT, 3.3 V at 2-A maximum
JP1 EN control. Shunt EN to GND to disable
TP1 VIN positive power point
TP2,TP11 GND power point
TP3 VIN positive monitor point
TP4,TP5,TP12,TP13 GND monitor test point
TP6 EN test point
TP7 Switch node test point
TP8 Test point for loop response measurements
TP9 VOUT positive monitor point
TP10 VOUT positive power point
4.2 Start-Up Procedure
1. Ensure that the jumper at JP1 (Enable control) pins 1 and 2 are covered to shunt EN to GND, disabling
the output.
2. Apply appropriate VIN voltage to VI (J1-2) and GND (J1-1).
3. Move the jumper at JP1 (Enable control) pins 1 and 2 (EN and GND) to enable the output.

Time [400s/div]
VOUT [100mV/div ]
ILoad [1A/div]
Output Current - A
Efficiency - %
0.001 0.01 0.1 1 2
20
30
40
50
60
70
80
90
100
TPS5D01_
VIN = 5V
VIN = 9V
VIN = 12V
VIN = 17V
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4.3 Efficiency
Figure 1 shows the efficiency for the TPS562231EVM at an ambient temperature of 25°C.
Figure 1. TPS562231EVM Efficiency
4.4 Load Transient Response
The TPS562231EVM response to load transient is shown in Figure 2. The voltage, current and time scale
are indicated in the figures.
Figure 2. TPS562231EVM Load Transient Response

VOUT [10mV/div ]
IL [1A/div] Time [2s/div]
VSW [5V/div]
VOUT [5mV/div ]
IL [1A/div]
Time [1s/div]
VSW [5V/div]
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4.5 Output Voltage Ripple
The TPS562231EVM output voltage ripple is shown in Figure 3,Figure 4, and Figure 5. The output
currents are as indicated.
Figure 3. TPS562231EVM Output Voltage Ripple in CCM
Figure 4. TPS562231EVM Output Voltage Ripple in DCM

VOUT [10mV/div ]
IL [1A/div] Time [2ms/div]
VSW [5V/div]
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Figure 5. TPS562231EVM Output Voltage Ripple on No-load

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5 Board Layout
This section provides a description of the TPS562231EVM, board layout, and layer illustrations.
5.1 Layout
The board layout for the TPS562231EVM is shown in Figure 6,Figure 7 and Figure 8. The top layer
contains the main power traces for VIN, VOUT, and ground. Also on the top layer are connections for the
pins of the TPS562231 and a large area filled with ground. Most of the signal traces are also located on
the top side. The input decoupling capacitors, C1, C2, and C3 are located as close to the IC as possible.
The input and output connectors, test points, and all of the components are located on the top side. The
bottom layer is a ground plane along with the switching node copper fill, signal ground copper fill and the
feed back trace from the point of regulation to the top of the resistor divider network.
Figure 6. Top Assembly

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Figure 7. Top Layer
Figure 8. Bottom Layer

Schematic, Bill of Materials, and Reference www.ti.com
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6 Schematic, Bill of Materials, and Reference
6.1 Schematic
Figure 9 is the schematic for the TPS562231EVM.
Figure 9. TPS562231EVM Schematic Diagram