NXP Semiconductors PCA9633, User Manual, Page: 7 / 16

UM10573 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 17 October 2012 7 of 16
NXP Semiconductors
UM10573
PCA9633 demo board OM6276
2.3.2 Bus SDA pull-up enable and bus SCL pull-up enable
Slider switches 5 and 6 (see Table 1 ) disable/enable the cable side pull-ups for the
I
2
C-bus. These switches must be ON for the MASTER Board (0) and the LAST SLAVE
board in the chain. All other boards between, must have these switches set to OFF. If
there are only two boards connected (MASTER and SLAVE), both boards must have
these switches set to ON.
2.3.3 Cable power OFF/ON
Slider switch 7 enables the battery power connection to the RJ45 cable on pin 1 of the
RJ45 Ethernet socket. It allows a single power source for the complete chain of boards
when all the boards have this switch set to ON. When a chain of boards is utilized, use a
single bench or wall power supply and remove the 9 V battery from each board. This
action is necessary as the typical 9 V battery cannot supply enough current to power
multiple boards.
The input power requirements are: 6 V (DC) to 12 V (DC), 100 mA per board maximum.
2.4 Board selection
[1] Only one board can be set as Master.
[2] The MASTER board must be at one end of the Ethernet cable for proper operation of the I
2
C-bus.
Subsequent SLAVE boards are not required to be in any certain order. Also, there may be gaps in the
SLAVE board addresses (e.g., it is possible to have SLAVE Boards 2, 4, 6 and no SLAVE Board 3 or 5).
2.5 Off-board LED drivers
The PCA9633 OM6276 demo board includes four NXP Semiconductors BSH112
high-current FET drivers for off-board LED circuitry. These devices, Q1 to Q4, are capable
of switching up to 60 V at 300 mA. Their outputs are connected to solder pads L1 to L4
with adjacent 5 V and GND connections. They are connected as “low side” switches to
ground configuration.
3. Operation
On the DIP switch push slider switch 8 to the ON position. The LEDs will immediately flash
and glow. To select a different mode of operation, press the MODE button (PB1). The LED
will flash amber a number of times to denote which mode has been entered. Use the other
three buttons (SELECT, PLUS, MINUS) to change the settings. The six different available
modes of operation are described in
Table 3 .
Table 2. Board address
SW3 SW2 SW1 Board Description
ON ON ON 0 master (default)
[1][2]
ON ON OFF 1 slave 1
ON OFF ON 2 slave 2
ON OFF OFF 3 slave 3
OFF ON ON 4 slave 4
OFF ON OFF 5 slave 5
OFF OFF ON 6 slave 6
OFF OFF OFF 7 slave 7