CAT9532WI Datasheet, PDF (1/17 Pages) ON Semiconductor – 16-bit Programmable LED Dimmer with I2C Interface

CAT9532
16-bit Programmable LED Dimmer with I²C Interface
FEATURES
„ 16 LED drivers with dimming control
„ 256 brightness steps
„ 16 open drain outputs drive 25 mA each
„ 2 selectable programmable blink rates:
– frequency: 0.593Hz to 152Hz
– duty cycle: 0% to 99.6%
„ I/Os can be used as GPIOs
„ 400kHz I²C bus compatible*
„ 2.3V to 5.5V operation
„ 5V tolerant I/Os
„ Active low reset input
„ RoHS-compliant 24-Lead SOIC, TSSOP and
24-pad TQFN (4 x 4mm) packages
APPLICATIONS
„ Backlighting
„ RGB color mixing
„ Sensors control
„ Power switches, push-buttons
„ Alarm systems
For Ordering Information details, see page 16.
DESCRIPTION
The CAT9532 is a CMOS device that provides 16-bit
parallel input/output port expander optimized for LED
dimming control. The CAT9532 outputs can drive
directly 16 LEDs in parallel. Each individual LED may
be turned ON, OFF, or blinking at one of two
programmable rates. The device provides a simple
solution for dimming LEDs in 256 brightness steps for
backlight and color mixing applications. The CAT9532
is suitable in I²C and SMBus compatible applications
where it is necessary to limit the bus traffic or free-up
the bus master’s timer.
The CAT9532 contains an internal oscillator and two
PWM signals that drive the LED outputs. The user can
program the period and duty cycle for each individual
PWM signal. After the initial set-up command to
program the Blink Rate 1 and Blink Rate 2 (frequency
and duty cycle), only one command from the bus master
is required to turn each individual open drain output ON,
OFF, or cycle at Blink Rate 1 or Blink Rate 2. Each
open drain LED output can provide a maximum output
current of 25mA. The total current sunk by all I/Os must
not exceed 200mA.
TYPICAL APPLICATION CIRCUIT
5V
5V
SDA
SCL
RESET
I²C/SMBus
Master
3 x 10kΩ
RS0 RS1
SDA ^VCC
SCL
RESET
LED0
LED1
CAT9532
LED11
A2
LED12
A1
A0
V_SS
LED15
RS11
GPIOs
* Catalyst Semiconductor is licensed by Philips Corporation to
carry the I²C Protocol.
Notes: LED0 to LED11 are used as LED drivers
LED12 to LED15 are used as regular GPIOs
© 2008 SCILLC. All rights reserved
1
Characteristics subject to change without notice
Doc. No. MD-9001 Rev. D