General Texas Instruments High Voltage Evaluation (TI HV EMV) User Safety Guidelines
Always follow TI's set-up and application instructions, including use of all interface components within their
recommended electrical rated voltage and power limits. Always use electrical safety precautions to help
ensure your personal safety and those working around you. Contact TI's Product Information Center
http://ti.com/customer support for further information.
Save all warnings and instructions for future reference.
WARNING
Failure to follow warnings and instructions may result in personal injury,
property damage or death due to electrical shock and burn hazards.
The term TI HV EVM refers to an electronic device typically provided as an open framed, unenclosed
printed circuit board assembly. It is intended strictly for use in development laboratory environments,
solely for qualified professional users having training, expertise and knowledge of electrical safety risks in
development and application of high voltage electrical circuits. Any other use and/or application are strictly
prohibited by Texas Instruments. If you are not suitable qualified, you should immediately stop from further
use of the HV EVM.
1. Work Area Safety:
a. Keep work area clean and orderly.
b. Qualified observer(s) must be present anytime circuits are energized.
c. Effective barriers and signage must be present in the area where the TI HV EVM and its interface
electronics are energized, indicating operation of accessible high voltages may be present, for the
purpose of protecting inadvertent access.
d. All interface circuits, power supplies, evaluation modules, instruments, meters, scopes, and other
related apparatus used in a development environment exceeding 50Vrms/75VDC must be
electrically located within a protected Emergency Power Off EPO protected power strip.
e. Use stable and non-conductive work surface.
f. Use adequately insulated clamps and wires to attach measurement probes and instruments. No
freehand testing whenever possible.
2. Electrical Safety:
As a precautionary measure, it is always good engineering practice to assume that the entire EVM
may have fully accessible and active high voltages.
a. De-energize the TI HV EVM and all its inputs, outputs and electrical loads before performing any
electrical or other diagnostic measurements. Revalidate that TI HV EVM power has been safely
de-energized.
b. With the EVM confirmed de-energized, proceed with required electrical circuit configurations,
wiring, measurement equipment hook-ups and other application needs, while still assuming the
EVM circuit and measuring instruments are electrically live.
c. Once EVM readiness is complete, energize the EVM as intended.
While the EVM is energized, never touch the EVM or its electrical
circuits, as they could be at high voltages capable of causing
electrical shock hazard.
3. Personal Safety
a. Wear personal protective equipment e.g. latex gloves or safety glasses with side shields or protect
EVM in an adequate lucent plastic box with interlocks from accidental touch.
Limitation for safe use:
EVMs are not to be used as all or part of a production unit.
This user's guide describes the specifications, board connection description, operation, and use of the
TPS92520EVM-074. The EVM consists of a CV boost stage, creating a regulated voltage rail that is used
by two TPS92520 ICs. The two TPS92520 ICs then create four current regulated channels for driving
strings of LEDs. The EVM is a representative of a lighting module suitable for automotive applications
creating advanced lighting features.
The TPS92520-Q1 buck current regulator device implements an adjustable constant on-time, valley
detect, current-mode control technique with programmable pseudo-fixed-frequency operation. Additional
features include the following:
•Wide input voltage range (4.5 V to 65 V)
•Analog adjustable output current setting
•Fault reporting
•Internal and external PWM dimming
The TPS92682-Q1 boost controller device implements a fixed-frequency peak-current mode control
technique with programmable switching frequency, slope compensation, and soft-start. Additional features
include the following:
•Wide input voltage range (4.5 V to 65 V)
•Programmable spread spectrum frequency modulation
•Programmable fault handling
•Adjustable output current setting
Optionally, to exercise advanced lighting control features, an accompanying EVM to the TPS92520 ECU
EVM, LMM EVM PWR901, can be used. The TPS92662-Q1 and TPS92663-Q1 (LMM, LED Matrix
Manager) devices include series-connected integrated switches for bypassing individual LEDs. The
individual sub-strings allow the device to accept either single or multiple current sources for bypassing
high current LEDs.
A complete schematic diagram, printed circuit board layouts, and bill of materials are included in this
document.
The TPS92520EVM-074 solution provides four current-regulated channels, providing up to 49.5 V, 1.6 A
for each channel (expandable voltage range with board modification), from a 12 V (nom) input. The four
TPS92520 channels and one dual-phase TPS92682 CV (constant voltage) channel are all configurable via
serial peripheral interface (SPI). The maximum output voltage of the TPS92682 CV boost can be
physically adjusted by modifying R34 (see Table 1). The EVM is designed to operate with an input voltage
in the range of 6 V to 40 V and provides a maximum total output power of 100 W (maximum of 50 W per
channel). For example, if one channel is operated at 50 W, the total power of the other three channels
must not exceed 50 W. The TPS92520EVM-074 provides a unique high-efficiency, SPI-programmable
solution with fault handling and reporting. It also includes standard ECU features: CAN (physical layer)
interface and reverse battery protection.
The EVM is operated via a standard TI LaunchPad (MSP-EXP432E401Y) and does not function if the
launchpad and GUI are not installed. It is possible to use your own or a different SPI controller after
reviewing the documentation for all parts in detail.
Figure 1 shows the block diagram of the system.
Description
Figure 1. TPS92520EVM-074 Block Diagram
2.1Typical Applications
This document outlines the operation and implementation of the TPS92520-Q1 as a four-channel LED
current regulator. Table 2 lists the specifications. For applications with a different input voltage range or
different I
range, refer to the TPS92520-Q1 1.5-A Dual Synchronous Buck LED Driver Data Sheet. The
LED
MSP-EXP432E401Y SimpleLink™ Ethernet MSP432E401Y MCU LaunchPad™ Development Kit controls
the TPS92520EVM-074 evaluation board. The MSP-EXP432E401Y is available on ti.com. Ensure that the
LaunchPad board from TI has been programmed using the UNIFLASH application before running the GUI.
Section 7 provides the programming instructions.
2.2Warnings
Observe the following precaution when using the TPS92520EVM-074 evaluation module. Do not leave the
EVM powered when unattended.
Do not touch. This is a hot surface and contact can cause burns.
CAUTION
Do not stare at the operation LED: (Risk Group 2 (RG2) at a distance <0.9m),
(Risk Group 1 (RG1) at a distance > 0.9m(, (Risk Group Exempt (RGE) at a
distance > 1.8 m). The LED may be hardmful to the eyes. See IEC62471:2008
("photo biological safety of lamps and lamp systems") for risk group definitions.
2.3Connector Description
Table 1 describes the connectors on the EVM and how to properly connect, set up, and use the
TPS92520EVM-074.
Figure 2 shows the connection diagram and the jumper locations of the TPS92520EVM-074.
J2
J35 V ControlJ3 controls the 5 V enable line. Select position 1–2 for launchpad interface.
J4VinInput Voltage Connector
J5
Spare Jumper >>
Transfer to Launch
Pad
Auxiliary SPI port connection. Use this port to monitor SPI BUS communications to
TPS92520 device U1 and U4.
Auxiliary SPI port connection. Use this port to monitor SPI BUS communications to
TPS92520 device U2 and U3.
Spare LaunchPad Jumper – remove from EVM and transfer to the LaunchPad at JP1 as
shown in Figure 3.
Figure 3. Jumper Placement for Launch Pad Use
J6, J7Expansion Port
J8, J10, J12Expansion Port
J9LMM
J11Channel Selector
J13, J14, J15,
J16
5VDC5 V Monitor5 V output of the U6 controlled LMR16006Y-Q1, fixed 5 V switching regulator
520-B1C1,
520-B1C2,
520-B2C1,
520-B2C2
VBOOSTBoost Output
GNDGroundGround test points
Launch Pad Port
Output PinsPositive outputs of the four buck regulators
These ports can be ignored. This port provides a connection port for EVM use with the
PWR879 microcontroller board (interface board used with TPS92518). This port also
provides a port to connect an additional TPS92520 EVM.
Provides connection point for additional SSN (slave select n) signals when using additional
TPS92520 EVM connections via the J7 port. Leave the port open for normal operation with
the launchpad.
Matrix Manager Connection. Port and GUI are compatible with the TPS92663EVM6-901.
Note that current sources are in parallel with 520-BxCx output pins. It is not recommended to
use both at the same time.
The TPS92663EVM6-901 has six inputs and the TPS92520-074 EVM provides four outputs.
J11 allows the user to power five of the six LED strings. Set J11 to route 520-B1C2 to either
the top string of LED controlled via Address 1 OR the bottom string of LEDs controlled by
Address 2.
LaunchPad connection ports. Ensure the launchpad is aligned before applying power or it
can result in the launchpad getting damaged.
TPS92682 Dual-Phase VC Boost Output. Adjust R34 to set the maximum boost output
The maximum boost output voltage can be adjusted to match your LED string requirements.
For safety requirements, the voltage has been limited to <50 V (49.5 V) by setting R34 to 5.1
kΩ. The voltage can be adjusted to a maximum of 65 V by changing the value of R34: R34 =
(2.39 × 100 k) / (VBOOST_Max - 2.39).
WARNING
Once R34 is changed, the maximum
slider position corresponds to the new
programmed value. A voltage greater
than 50 V can require special handing
precautions at your location. Consult
your locallab managerandsafety
codes before making any changes to
the EVM.
3REACH Compliance
In compliance with the Article 33 provision of the EU REACH regulation, TI is notifying you that this EVM
includes component or components that contain at least one substance of very high concern (SVHC)
above 0.1%. These uses from Texas Instruments do not exceed one ton per year. The SVHC
specifications are:
COMPONENT
MANUFACTURER
PHOENIX CONTACT GmbH &
Co. KG
4Performance Specifications
This section provides the performance specifications and requirements for the dual-phase CV TPS926682
boost and TPS92520 buck current regulators.
4.1ECU Current Regulator
Table 2 provides the EVM electrical performance specifications for the lighting ECU.
Note: derating of 100 W maximum is
necessary below 10 V
OUTPUT CHARACTERISTICS
Total LED forward voltage, V
Output voltage V
OUT
Maximum output current, I
Maximum Channel Output Power, P
(LED)
Maximum voltage on 520-CxBx terminal65V
LED
OUT
SYSTEMS CHARACTERISTICS
TPS92520 Switching frequency F
SW
Target for this EVM design (On Time = 7)400kHz
5Performance Data and Typical Characteristic Curves
Figure 5 shows the efficiency results for the system versus CH
LED in series. It is important to note that the efficiency results include the all EVM power losses, including
the input reverse battery protection circuitry.
100W
10A
49.5V
1.6A
50W
. The results shown have used eight
xIADJ
Figure 5. ECU Metrics, VIN= 12 V, TPS92682 Boost Channel and 2 Channels from 1 x TPS92520 IC
5.1Start-up Waveforms
Figure 6 shows the start-up waveforms, V
string of 7×LEDs are connected to the buck output and the boost is set to 47 V.
SLUUC29B–August 2019–Revised October 2019
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, COMP, and the switch-node voltage (SWN). In this setup, a