PCU9955
16-channel UFm I
2
C-bus 57 mA constant current LED driver
Rev. 2.1 — 29 June 2015
Product data sheet
1. General description
The PCU9955 is an Ultra-Fast mode (UFm) I
2
C-bus controlled 16-channel constant
current LED driver optimized for dimming and blinking 57 mA Red/Green/Blue/Amber
(RGBA) LEDs in amusement products. Each LEDn output has its own 8-bit resolution
(256 steps) fixed frequency individual PWM controller that operates at 31.25 kHz with a
duty cycle that is adjustable from 0 % to 99.6 % to allow the LED to be set to a specific
brightness value. An additional 8-bit resolution (256 steps) group PWM controller has both
a fixed frequency of 122 Hz and an adjustable frequency between 15 Hz to once every
16.8 seconds with a duty cycle that is adjustable from 0 % to 99.6 % that is used to either
dim or blink all LEDs with the same value.
Each LEDn output can be off, on (no PWM control), set at its individual PWM controller
value or at both individual and group PWM controller values. The PCU9955 operates with
a supply voltage range of 3 V to 5.5 V and the constant current sink LEDn outputs allow
up to 40 V for the LED supply. The output current is adjustable with an 8-bit linear DAC
from 225
A
to 57 mA.
This device has built-in open, short load and overtemperature detection circuitry. The
thermal shutdown feature protects the device when internal junction temperature exceeds
the limit allowed for the process.
The PCU9955 device is the first LED controller device in a new Ultra Fast-mode (UFm)
I
2
C-bus family. UFm I
2
C-bus devices offer higher frequency (up to 5 MHz). The UFm
I
2
C-bus slave devices operate in receive-only mode. That is, only I
2
C writes to PCU9955
are supported. As such, there are no status registers in PCU9955. The PCU9955 allows
significantly higher data transfer rate compared to the Fast-mode Plus versions
(PCA9952/55).
Software programmable LED Group and three Sub Call I
2
C-bus addresses allow all or
defined groups of PCU9955 devices to respond to a common I
2
C-bus address, allowing
for example, all red LEDs to be turned on or off at the same time, thus minimizing I
2
C-bus
commands. On power-up, PCU9955 will have a unique Sub Call address to identify it as a
16-channel LED driver. This allows mixing of devices with different channel widths. Four
hardware address pins on PCU9955 allow up to 16 devices on the same bus.
The Software Reset (SWRST) function allows the master to perform a reset of the
PCU9955 through the I
2
C-bus, identical to the Power-On Reset (POR) that initializes the
registers to their default state causing the output current switches to be OFF (LED off).
This allows an easy and quick way to reconfigure all device registers to the same
condition.
NXP Semiconductors
PCU9955
16-channel UFm I
2
C-bus 57 mA constant current LED driver
2. Features and benefits
16 LED drivers. Each output programmable at:
Off
On
Programmable LED brightness
Programmable group dimming/blinking mixed with individual LED brightness
Programmable LEDn output enable delay to reduce EMI and surge currents
16 constant current output channels can sink up to 57 mA, tolerate up to 40 V when
OFF
Output current adjusted through an external resistor
Output current accuracy
6
% between output channels
8
% between PCU9955 devices
Thermal shutdown for overtemperature
5 MHz Ultra Fast-mode compatible I
2
C-bus interface
256-step (8-bit) linear programmable brightness per LEDn output varying from fully off
(default) to maximum brightness using a 31.25 kHz PWM signal
256-step group brightness control allows general dimming (using a 122 Hz PWM
signal) from fully off to maximum brightness (default)
256-step group blinking programmable from 15 Hz to 16.8 s and duty cycle from 0 %
to 99.6 %
Output state change programmable on the Acknowledge (bit 9, this bit is always set
to 1 by I
2
C-bus master) or the STOP Command to update outputs byte-by-byte or all at
the same time (default to ‘Change on STOP’).
4 hardware address pins allow 16 PCU9955 devices to be connected to the same
I
2
C-bus and to be individually programmed
4 software programmable I
2
C-bus addresses (one LED Group Call address and three
LED Sub Call addresses) allow groups of devices to be addressed at the same time in
any combination (for example, one register used for ‘All Call’ so that all the PCU9955s
on the I
2
C-bus can be addressed at the same time and the second register used for
three different addresses so that
1
⁄
3
of all devices on the bus can be addressed at the
same time in a group). Software enable and disable for each programmable I
2
C-bus
address.
Unique power-up default Sub Call address allows mixing of devices with different
channel widths
Software Reset feature (SWRST Call) allows the device to be reset through the
I
2
C-bus
8 MHz internal oscillator requires no external components
Internal power-on reset
Noise filter on USDA/USCL inputs
No glitch on LEDn outputs on power-up
Low standby current
Operating power supply voltage (V
DD
) range of 3 V to 5.5 V
5.5 V tolerant inputs on non-LED pins
40 C
to +85
C
operation
PCU9955
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 2.1 — 29 June 2015
2 of 40
NXP Semiconductors
PCU9955
16-channel UFm I
2
C-bus 57 mA constant current LED driver
ESD protection exceeds 2000 V HBM per JESD22-A114 and 750 V CDM per
JESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 Class II, Level B
Package offered: HTSSOP28
3. Applications
Amusement products
RGB or RGBA LED drivers
LED status information
LED displays
LCD backlights
Keypad backlights for cellular phones or handheld devices
4. Ordering information
Table 1.
Type
number
Ordering information
Topside
mark
Package
Name
Description
Version
SOT1172-2
HTSSOP28 plastic thermal enhanced thin shrink small outline package;
28 leads; body width 4.4 mm; lead pitch 0.65 mm;
exposed die pad
PCU9955TW PCU9955
PCU9955
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 2.1 — 29 June 2015
3 of 40
NXP Semiconductors
PCU9955
16-channel UFm I
2
C-bus 57 mA constant current LED driver
5. Block diagram
A0 A1 A2 A3
REXT
I/O
REGULATOR
LED0
LED1
LED14
LED15
PCU9955
DAC0
USCL
USDA
INPUT FILTER
individual LED
current setting
8-bit DACs
DAC1
UFm I
2
C-BUS
CONTROL
DAC
14
DAC
15
V
DD
V
SS
RESET
200 kΩ
POWER-ON
RESET
OUTPUT DRIVER, DELAY CONTROL
AND THERMAL SHUTDOWN
INPUT
FILTER
LED STATE
SELECT
REGISTER
PWM
REGISTER X
BRIGHTNESS
CONTROL
repetition rate 31.25 kHz
÷
256
8 MHz
OSCILLATOR
31.25 kHz
GRPFREQ
REGISTER
MUX/
CONTROL
GRPPWM
REGISTER
'0' – permanently OFF
'1' – permanently ON
DIM CLOCK
002aaf093
Dim repetition rate = 122 Hz.
Blink repetition rate = 15 Hz to every 16.8 seconds.
Fig 1.
Block diagram of PCU9955
PCU9955
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 2.1 — 29 June 2015
4 of 40
NXP Semiconductors
PCU9955
16-channel UFm I
2
C-bus 57 mA constant current LED driver
6. Pinning information
6.1 Pinning
REXT
A0
A1
A2
A3
LED0
LED1
LED2
LED3
1
2
3
4
5
6
7
8
9
(1)
28 V
DD
27 USDA
26 USCL
25 RESET
24 V
SS
23 LED15
22 LED14
21 LED13
20 LED12
19 V
SS
18 LED11
17 LED10
16 LED9
15 LED8
002aaf094
PCU9955TW
V
SS
10
LED4 11
LED5 12
LED6 13
LED7 14
(1) Thermal pad; connected to V
SS
.
Fig 2.
Pin configuration for HTSSOP28
6.2 Pin description
Table 2.
Symbol
REXT
A0
A1
A2
A3
LED0
LED1
LED2
LED3
LED4
LED5
LED6
LED7
LED8
LED9
LED10
LED11
LED12
Pin description
Pin
1
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
20
Type
I
I
I
I
I
O
O
O
O
O
O
O
O
O
O
O
O
O
Description
current set resistor input; resistor to ground
address input 0
[1]
address input 1
[1]
address input 2
[1]
address input 3
[1]
LED driver 0
LED driver 1
LED driver 2
LED driver 3
LED driver 4
LED driver 5
LED driver 6
LED driver 7
LED driver 8
LED driver 9
LED driver 10
LED driver 11
LED driver 12
PCU9955
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 2.1 — 29 June 2015
5 of 40
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