NXP Semiconductors PCA9955 User manual

UM10572
PCA9955 demonstration board OM13330
Rev. 1 — 7 June 2012 User manual
Document information
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Keywords Fm+ I2C-bus, PCA9955, RGB and white LEDs, 16-channel × 8-bit PWMs
Abstract The OM13330 is an add-on to 9-pin connector of the NXP I2C demo board
2005-1 or Fm+ I2C-bus development board. This daughter board makes it
easy to test and design with the PCA9955, a 16-channel Fast-mode Plus
(Fm+) 57 mA constant current and outputs allow up to 40 V for LED
supply. These boards, along with the Win-I2CUSB Lite GUI (PC based),
provide an easy to use evaluation platform.

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User manual Rev. 1 — 7 June 2012 2 of 16
Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
NXP Semiconductors UM10572
PCA9955 demonstration board OM13330
Revision history
Rev Date Description
v.1 20120607 user manual; initial release

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PCA9955 demonstration board OM13330
1. Introduction
The PCA9955 evaluation board features LEDs for color mixing, blinking and dimming
demonstrations. A graphical interface allows the easyexploration of the different functions
of the driver. The board can be connected in series with other I2C-bus demo boards to
create an evaluation system.
The IC communicates to the host via the industry standard I2C-bus/SMBus port. The
evaluation software runs under Microsoft Windows PC platform.
2. Features
•A complete evaluation platform for the PCA9955 16-channel Fm+ I2C-bus constant
current LED driver
•Easy to use GUI-based software demonstrates the capabilities of the PCA9955
•On-board RGB and White LEDs for visual experience
•Convenient test points for easy scope measurements and signal access
•USB interface to the host PC
•No external power supply required
3. Getting started
3.1 Assumptions
Familiarity with the I2C-bus is helpful but not required.
3.2 Static handling requirements
3.3 Minimum system requirements
•PC Pentium 60 processor (or equivalent), 8 MB RAM, 10 MB of hard drive space
•One USB port (either 2.0 or 1.1 compatible)
•Windows 98SE, ME, 2000, XP, or Vista
•I2C demonstration board 2005-1 (OM6275) or WIN-I2CUSB board (from
www.nxp.com/redirect/demoboard.com)
3.4 Power requirements
The NXP demonstration board I2C 2005-1 and OM13330 hardware obtain power from the
PC USB port. Take care to not exceed the USB port current capabilities.
CAUTION
This device is sensitive to ElectroStatic Discharge (ESD). Therefore care should be taken
during transport and handling. You must use a ground strap or touch the PC case or other
grounded source before unpacking or handling the hardware.

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PCA9955 demonstration board OM13330
4. Installation
4.1 I2C demo board 2005-1 and WIN-I2CUSB Lite software
The OM13330 is a daughter card to the OM6275 I2C demo board 2005-1. You can
download the WIN-I2CUSB Lite Software, the OM6275 user manual UM10206, and find
ordering information at the NXP web site ics.nxp.com/support/boards/i2c20051/.
The Win-I2CUSB Lite software from The Boardshop runs on Windows 98SE, ME, 2000,
and XP, and is compatible with any PC hardware having a minimum of a Pentium
processor and a USB port. The software allows the user to select one of the I2C-bus
devices on the board from a menu and also provides a Universal mode (I2C Expert mode)
to allow users to create their own I2C-bus commands with the same I2C-bus devices.
4.2 OM13330 connection to I2C demo board 2005-1
The I2C demo board 2005-1 should be disconnected from your PC before mounting the
OM13330 board on to it. The OM13330 board has a 9-pin female connector (J4) that
connects to the JP1 male connector on the I2C demo board 2005-1 as shown in Figure 1.
With both boards facing you, with USB connector on the right-hand side as shown in the
Figure 1, connect the OM13330 board to the I2C demo board 2005-1 before connecting
the USB cable. Once the board is connected, connect the USB cable and start the
WIN-I2CUSB Lite software. You are now ready to evaluate the PCA9955.
Fig 1. PCA9955 demo board (OM13330) mounting to the I2C demo board 2005-1 (OM6275)

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PCA9955 demonstration board OM13330
4.3 OM13330 connection to Win-I2CUSB hardware adapter board
The Win-I2CUSB board should be disconnected from your PC before connecting the
OM13330 board on to it. The OM13330 board has a 14-pin male connector (J2) that
connects to the 14-pin male connector (J1) on the Win-I2CUSB board as shown in
Figure 2.
Connect the OM13330 board to the Win-I2CUSB board before connecting the USB cable.
Once the board is connected, connect the USB cable and start the WIN-I2CUSB Lite
software. You are now ready to evaluate the PCA9955.
Fig 2. PCA9955 demo board (OM13330) connecting to the Win-I2CUSB board

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PCA9955 demonstration board OM13330
5. Hardware description
Figure 3 shows the following items on the hardware:
•J4 (9-pin) is for connection to JP1 on I2C demo board 2005-1.
•J3 and J5 (5-pin) are for connection to PCA9665/PCU9669 mini boards and cascade
the second PCA9955 demo board.
•J1 selects VDD power for PCA9955, connected 1-2 for VDD = 3.3 V and connected 2-3
for VDD = 5 V.
•SW1 4-position DIP switch to select I2C-bus address A[0:3] = SW1[1:4] for this device
(default is 0xC0, all switches are ON position).
•J2 (14-pin) is for connection to J1 on Win-I2CUSB board.
•4-channel to drive four White LEDs (D2, D4, D6, D9) and 12-channel to drive
four RGB LEDs (D3, D5, D7, D8).
•J6, J7 and J8 are GND pins for probing use.
Fig 3. PCA9955 demo board (OM13330)

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PCA9955 demonstration board OM13330
6. Schematic
Fig 4. PCA9955 demo board schematic
019aac728
1
2
3
4
5
A0
A1
A3
A2
A0
A1
A3/OE
A2
REXT
PCA9952TW, PCA9955TW, PCU9955TW
6
7
8
9
LED0
LED1
LED3
LED2
LED0
LED1
LED3
LED2
10
11
12
GND
LED5
LED4 VSS
LED5
LED4
13
14
LED6
LED7 LED6
LED7
U1
28
27
26
25
24 GND
RESET
SDA/USDA
SCL/USCL
VSS
RESET
VDD
23
22
21
20
LED15
LED14
LED12
LED13
LED15
LED14
LED12
LED13
19
18
17
GND
LED10
LED11
VSS
LED10
LED11
16
15
LED9
LED8
LED9
LED8
R10
R11
0 Ω
0 Ω
R9
2.8 kΩ
(ISET max = 20.4 mA)
SW1
SW DIP-4/SM
R1 10 kΩ R2 10 kΩ R3 10 kΩ R4 10 kΩ
VDD_IN
(output enable
for PCA9952)
TP1 1
R5 100 Ω R6 100 Ω
R13 100 Ω R14 100 Ω
SDA_USDA filter
SCL_USCL filter
do not populate
R7
10 kΩ
1 2 3
J1
+3.3 V +5 V
VDD_IN
R8
10 Ω
C2
0.1 μF
C3
4.7 μF
U
varistor 8 V
RV1
R12
1 kΩ
D1
LTST-C170KGKT
1
2
3
+24 V
SDA_USDA_1
+5 V
4
5
SCL_USCL_1
GND
J3
C1
10 μF
CONN TRBLK-5
5-pin connector to/from PCU9669 UFm
I2C master board to drive PCU9955 or
to/from another I2C slave PCA/PCU9955
demo board
1
2
3
+5 V
+3.3 V
4
5
SCL_USCL_1
J4
C6
10 μF
CON9-female
6
7
SDA_USDA_1
GND
8
9RESET
C7
10 μF
9-pin connector to/from I2C 2005-1
demo board for PCA9952/PCA9955
3
2
1
J6
1GND
2I/O1
4
VCC
3
I/O2
U2
close to 5-pin connector J3
PRTR5V0U2AX
C25
0.01 μF
+5 V
L1
BLM18BD471SN1
SDA_USDA_1 SDA_USDA-filter
L2
BLM18BD471SN1
SCL_USCL_1 SCL_USCL-filter
(470 Ω at 100 MHz)
3
2
1
J8
1GND
2I/O1
4
VCC
3
I/O2
U3
close to 5-pin connector J5
PRTR5V0U2AX
C26
0.01 μF
+5 V
L3
BLM18BD471SN1
SDA_USDA_2 SDA_USDA-filter
L4
BLM18BD471SN1
SCL_USCL_2 SCL_USCL-filter
(470 Ω at 100 MHz)
C9
0.1 nF
C10
0.1 nF
C11
0.1 nF
C12
0.1 nF
C13
0.1 nF
C14
0.1 nF
C15
0.1 nF
C16
0.1 nF
C17
0.1 nF
C18
0.1 nF
C19
0.1 nF
C20
0.1 nF
C21
0.1 nF
C22
0.1 nF
C23
0.1 nF
C24
0.1 nF
D2
LED0
LW-E67C-white
+5 V
A1
C2
A2
C1
C3
A3
D3 LED[1:3]
LRTB_G6SG
D4
LED4
LW-E67C-white
R15 0 Ω
R16 0 Ω
R17 0 Ω
R18 0 Ω
LED0
LED1
LED2
LED3
R19 0 Ω
R20 0 Ω
R21 0 Ω
LED4
LED5
LED6
R22 0 Ω
R23 0 Ω
R24 0 Ω
LED7
LED8
LED9
R25 0 Ω
R26 0 Ω
R27 0 Ω
LED10
LED11
LED12
R28 0 Ω
R29 0 Ω
R30 0 Ω
LED13
LED14
LED15
A1
C2
A2
C1
C3
A3
D5 LED[5:7]
LRTB_G6SG
D6
LED8
LW-E67C-white
A1
C2
A2
C1
C3
A3
D7 LED[9:11]
LRTB_G6SG
D9
LED12
LW-E67C-white
A1
C2
A2
C1
C3
A3
D8 LED[13:15]
LRTB_G6SG
3
2
1
J7
GND
GND
GND
1
2
3
+24 V
SDA_USDA_2
+5 V
4
5
SCL_USCL_2
GND
J5
C8
10 μF
CONN TRBLK-5
5-pin connector to/from PCU9669 UFm
I2C master board to drive PCU9955 or
to/from another I2C slave PCA/PCU9955
demo board
1
3
5
7
9
11
13
2
4SCL_USCL_2
(VP) VDO_IN
6
8
10
GND
SDA_USDA_2
12
14 +5 V
J2
GND
+3.3 V
C4
10 μF
VP supplies the
power to the I2C
pull-up resistors
on WIN-I2CUSB
C5
10 μF
14-pin connector to/from
WIN-I2CUSB Fm+ I2C master
to drive PCA9952/PCA9955
HEADER 7x2/SM
I2CUSB CONNECTOR
AVR-M1608C080M

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PCA9955 demonstration board OM13330
7. OM13330 demonstration board main components
8. PCA9955 evaluation steps
The PCA9955 functions are controlled by WIN-I2CUSB Lite GUI. Refer to the PCA9955
data sheet for additional information on the registers and functionality.
Connect the hardware as described in Section 4. The PCA9955 demo board address is
set to 0xC0 on SW1 as A[0:3] = SW1[1:4] = 0000 (0 →ON, 1 →OFF). When you have
correctly installed the software and the demonstration board hardware is connected and
recognized by the computer, start the Win-I2CUSB Lite software. As shown in Figure 5,
when the demonstration board hardware is correctly connected to the USB port and the
computer recognizes it, the message ‘Hardware Detected’ is displayed on the bottom of
the window.
Switched 3.3 V and 5.0 V power supplies are controlled through the ‘Options’ menu or by
double-clicking the 3.3 V or 5.0 V symbols on the bottom of the window. Power supplies
are disabled by default, and must be enabled before using the I2C-bus devices on the
board. I2C-bus frequency is controlled through the ‘Options’ menu or by double-clicking on
the frequency symbol on the bottom of the window.
8.1 Color mixing and dimming LEDs
1. From the ‘Device’ drop-down menus, select ‘LED Blinkers and Dimmers’, and from
the subsequent drop-down menu select ‘PCA9955 16-channel Constant Current LED
Driver’ as shown in Figure 5.
2. Check the ‘Auto Write On’ box (lower left), uncheck the ‘Low power mode (oscillator
off)’ box to enable the device to ‘Normal mode’ (upper left).
3. The device configuration screen is displayed by clicking the following options:
–‘PWM 0 to 7’ individual brightness control for LED0 to LED7 as shown in Figure 6.
–‘PWM 8 to 15’ individual brightness control for LED8 to LED15 as shown in
Figure 7.
–‘LEDOUT’ LED driver output state for LED0 to LED15 as shown in Figure 8.
–‘Output Gain’ LED output current setting for LED0 to LED15 as shown in Figure 9.
Table 1. OM13330 demo board main components
Device Description Address/LED output Location
PCA9955TW 16-channel Fm+ I2C-bus 57 mA
constant current LED driver 0xC0 for I2C demo board 2005-1 interface U1
LW-E67C White LED LED0, LED4, LED8, LED12 D2, D4, D6, D9
LRTB_G6SG RGB LED LED1, LED2, LED3 D3
LRTB_G6SG RGB LED LED5, LED6, LED7 D5
LRTB_G6SG RGB LED LED9, LED10, LED11 D7
LRTB_G6SG RGB LED LED13, LED14, LED15 D8
LTST-C170KGKT Green LED for PCA9955 power supply
either 3.3 V or 5 V indicator -D1

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PCA9955 demonstration board OM13330
–‘Other’ GRPPWM is group PWM for global brightness control, GRPFREQ is group
frequency for global blinking control when group control = blinking in Mode 2
register, PWMALL is brightness control for all LED outputs, OFFSET is control LED
output delay offset, IREFALL is control output current for all LEDs as shown in
Figure 10.
4. Click the ‘LEDOUT’ configuration screen and select ‘PWMn & GRPPWM’ for LED[1:3]
(see Figure 8).
5. Click the ‘Output Gain’ configuration screen and adjust the IREF[1:3] = 0x30 for
LED[1:3] output current at 3.8 mA = 48 ×80 μA (see Figure 9).
6. Click the ‘PWM 0 to 7’ configuration screen and move the PWM1 (red) PWM2 (green)
PMW3 (blue) bars for color mixing (see Figure 6).
7. Once you set a color on D3 RGB LED with the PWM[1:3] values, click the ‘Other’
configuration screen and move the GRPPWM bar for dimming effect (see Figure 10).
Fig 5. Drop-down menu selections

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PCA9955 demonstration board OM13330
Fig 6. Device configuration screen for PWM[0:7]
Fig 7. Device configuration screen for PWM[8:15]