Datasheet
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1366A
IEEE802.3AF/AT POWER-OVER-ETHERNET POWER SOURCING EQUIPMENT CONTROLLER
LTC4266
6
pull-up resistors on these pins, so with all four
switches of S1 open the address will be 0101111b.
All LTC4266 chips also respond to the global ad-
dress 0110000b regardless of the state of their AD3-
AD0 pins.
I
2
C Bus Lines
The LTC4266 has separate pins for SDAIN and
SDAOUT to facilitate the use of optocouplers. The
DC1366A provides test points for both SDAIN and
SDAOUT to make it easy to connect to any type of
breadboard or development tools the user desires.
However, the DC590B uses a single bidirectional
SDA line. Therefore the DC1366A board includes a
jumper (JP3) to tie SDAIN to SDAOUT. JP3 must be
in the TIE position when using the DC590B board to
control the DC1366A board.
The DC590B board includes pull-up resistors on the
SDA and SCL lines, while the DC1366A board has
none. If the DC590B board is replaced by a different
I
2
C master, the user must make sure there are ap-
propriate pull-up resistors on SDA and SCL.
Interrupts
The LTC4266 includes an open-drain interrupt line
for signaling the host controller when it needs ser-
vice. This signal can be accessed on the DC1366A
board at TP9. An LED is also included for conven-
ience.
Connecting Multiple DC1366A Boards
To use multiple DC1366A boards on a common I
2
C
bus, simply connect their J6 connectors together
with ribbon cable (14-conductor, 1mm pitch).
Up to sixteen DC1366A boards can be controlled by
a single I
2
C master. Remember to set each board to
a different I
2
C address using the DIP switch.
The DC590B can’t supply enough current on V
DD
for
more than five or six DC1366A boards; an external
V
DD
power supply is recommended if more than five
DC1366A boards are connected together.
If a large number of DC1366A boards are connected
to a single V
EE
supply, be aware that banana patch
cords are only rated for about 14A. To avoid ex-
ceeding the ampacity of the patch cords, the boards
should be connected in a star configuration rather
than connecting the boards in a chain.
GUI Software
The GUI application software is a powerful tool for
learning the LTC4266 register set and developing
power management protocols. See the
LTC4266
Demonstration Software Users Manual
for more de-
tails.