
NXP Semiconductors
PCU9955
16-channel UFm I 2 C-bus 57 mA constant current LED driver
5. Block diagram
A0 A1 A2 A3
REXT
LED0
LED1
LED14
LED15
PCU9955
I/O
REGULATOR
DAC0
USCL
USDA
INPUT FILTER
individual LED
current setting
DAC1
UFm I 2 C-BUS
CONTROL
8-bit DACs
DAC
14
DAC
V DD
V SS
RESET
POWER-ON
RESET
200 k Ω
INPUT
FILTER
PWM
15
OUTPUT DRIVER, DELAY CONTROL
AND THERMAL SHUTDOWN
LED STATE
SELECT
REGISTER
REGISTER X
BRIGHTNESS
CONTROL
repetition rate 31.25 kHz
÷ 256
31.25 kHz
GRPFREQ
REGISTER
GRPPWM
MUX/
CONTROL
8 MHz
REGISTER
OSCILLATOR
DIM CLOCK
'0' – permanently OFF
'1' – permanently ON
002aaf093
Dim repetition rate = 122 Hz.
Blink repetition rate = 15 Hz to every 16.8 seconds.
Fig 1.
Block diagram of PCU9955
PCU9955
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 2 — 2 October 2012
? NXP B.V. 2012. All rights reserved.
4 of 39