Description
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SLUUBM0 – May 2017
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Copyright © 2017, Texas Instruments Incorporated
TPS92518EVM Dual Buck Controller Evaluation Module
30
LEDSPIMCUEVM-879 Schematic, Page 4
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25
List of Tables
1
Connector Descriptions
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2
2
Test Points
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3
3
TPS92518 EVM Performance Specifications
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3
4
TPS92518EVM-878 Bill of Materials
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14
Trademarks
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All other trademarks are the property of their respective owners.
1
Description
The complete two-board TPS92518EVM solution provides a dual-channel, high-brightness LED current
regulator which is configurable via a graphical user interface (GUI). It is designed to operate with an input
voltage in the range of 6.5–65 V. The EVM is setup for default output currents of 538 mA per channel,
easily adjustable to different currents up to 1.65 A, for an LED stack between approximately 3 V to nearly
65 V. The TPS92518 provides high efficiency, high bandwidth, fast PWM dimming, SPI dimming, and
adjustable on-time.
1.1
Typical Applications
This manual outlines the operation and implementation of the TPS92518 as a dual-channel LED current
regulator with the specifications listed in
Table 1
. For applications with a different input voltage range or
different output voltage range, refer to the TPS92518 data sheet (
SLUSCR7
). The TPS92518EVM-878
evaluation board is designed to be controlled by a TI microcontroller board, part number
LEDSPIMCUEVM-879, available separately, although it can be controlled by any SPI-capable control
system. Note that the TPS92518x supports a means to enable the part without SPI communication. By
applying a voltage above the second threshold level, 23.6 V typical, on the ENABLE pin, the state of the
LEDxEN register is bypassed. This allows a TPS92518 to be powered and operated using the default
register values (for details, refer to the TPS92518 data sheet (
SLUSCR7
)).
1.2
Connector Description
Table 1
describes the connectors and
Table 2
lists the test points on the EVM and how to properly
connect, set up, and use the TPS92518EVM-878.
Table 1. Connector Descriptions
Connector
Label
Description
J1 and J18
VIN, GND
J1 connects power to channel 1 of the board, and J18 connects power to channel 2.
The evaluation board is set up with both channel supplies connected through R15,
so power connection can be to either J1 or J18 to power both channels from a
single supply. The board silkscreen identifies power (one pin) and ground (two pins)
connections on each connector.
J2 and J3
LED+, LED– and GND
J2 connects the channel 1 output to the LED load, and J3 connects the channel 2
output to a separate LED load. The leads to the LED load should be twisted and
kept short to minimize voltage drop, inductance, and EMI. The board silkscreen
identifies LED+ and LED– and GND.
J4
SPI control header
J4 allows attachment of a header cable for SPI control of the chip. The board
silkscreen identifies GND, MISO, MOSI, SCK, and SSN.
J10 and J11
SPI control from an
LEDSPIMCUEVM-879
controller board
J10 and J11 allow daisy-chaining TPS92518EVM-878 boards to each other with one
LEDSPIMCUEVM-879 control board attached to the left-hand side of the left-most
evaluation board for controlling the TPS92518. This interface allows control of the
chip hardware enable line, PWM inputs to both channels, SPI lines, and hardware
address lines for multiple SSN settings for systems that have multiple
TPS92518EVM-878 boards controlled by a single LEDSPIMCUEVM-879 controller
interface board.
J12 and J14
SPI MISO pullup resistor
jumpers
J12 and J14 provide for two different values of pullup resistor to the MISO line, 2.2
k
Ω
and 4.7 k
Ω
provided on the evaluation board.
