1
Rev. 0
DESCRIPTION
LT3967/LT3960
1.3A 8-Switch Matrix LED Dimmer with I
2
C
to CAN-Physical Layer Transceiver
Demonstration circuit 2686A is a 1.3A 8-switch matrix LED
dimmer system with an I
2
C to CAN-physical transceiver
featuring the
. This demonstration
circuit connects directly to a LED string and LED driver
demonstration circuit to allow for independent dimming
control of up to 8 channels of LEDs. A Linduino
®
One
demonstration circuit is used to interface with the board
and can connect in one of two different ways:
1. Connect directly to a Linduino One demonstration
circuit with a QuikEval™ ribbon cable.
2. Connect using the LT3960 break-off board to con-
nect to the I
2
C master device, but pass data over two
twisted pair lines to the LT3960 on the main PCB.
The LT3967 matrix dimmer features 8 individually con-
trolled 1.3A rated floating NMOS switch channels and can
support up to 56V of LEDs per device. The channels of
the LT3967 can be configured for series connections, or
non-series connections. Additional DC2686A demo cir-
cuits can be connected in series for higher number of
LEDs, or in parallel to allow for higher current operation.
Resistors are used to configure both the I
2
C slave address
as well as the default start-up state. The default configu-
ration for DC2686A sets the I
2
C address as 0000 with all
LEDs off. See the LT3967 data sheet for details.
All registered trademarks and trademarks are the property of their respective owners.
The LT3960 I
2
C to CAN-Physical transceiver is used to
send and receive I
2
C data through harsh or noisy envi-
ronments at up to 400kb/s using the CAN-Physical layer
for differential signaling over twisted pair connections.
Both SDA and SCL data lines are converted to differential
signals and are shared between devices connected to the
bus. This allows for physical separation of the I
2
C source
with the LT3960 transceiver board and the LT3967 main
PCB along with the LED driver.
This demo circuit is designed to be easily configured and
interfaced with a compatible low output capacitance LED
driver and LED string. It can easily be directly attached
to a buck LED driver or a floating buck-mode LED driver.
More sophisticated setups with series matrix dimmers
for higher number of LEDs such as 12 or 16 is possible.
Please consult factory applications for details or look for
more details on analog.com.
The LT3967 and LT3960 data sheets give complete
description of the parts, their operation and applications
information. The data sheets must be read in conjunc-
tion with this demo manual for demonstration circuit
DC2686A. The LT3967EFE is assembled in a thermally
enhanced 28-lead TSSOP package. The LT3960EMSE is
assembled in a 10-lead MSOP package.
