CAT9552WI Datasheet, PDF (1/17 Pages) ON Semiconductor – 16-Channel I2C-bus LED Driver with Programmable Blink Rate

16-Channel I²C-bus LED Driver with
Programmable Blink Rate
CAT9552
FEATURES
„ 16 LED drivers with On/Off and programmable
blink rate control
„ 2 selectable, programmable blink rates:
– frequency: 0.172Hz to 44Hz
– duty cycle: 0% to 99.6%
„ 16 open drain outputs drive 25mA each
„ 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
„ Office machines
„ Appliance control panels
„ Alarm systems
„ Point of sale displays
For Ordering Information details, see page 16.
DESCRIPTION
The CAT9552 is a 16-channel, parallel input/output
port expander optimized for LED On/Off and blinking
control. Each individual LED may be turned ON, OFF,
or set to blinking at one of two programmable rates.
The CAT9552 is compatible with I²C and SMBus
applications where it is desireable to limit the bus
traffic or free-up the bus master’s internal timer. Three
address pins allow up to eight CAT9552 devices to
occupy the same bus.
The CAT9552 contains an internal oscillator and two
PWM signals, which drive the LED outputs. The user
may program the period and duty cycle for each
individual PWM signal. After an 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 sink a maximum current of 25mA.
The total continuous current sunk by all I/Os must not
exceed 200mA per package.
TYPICAL APPLICATION CIRCUIT
5V
5V
SDA
SCL
RESET
I²C/SMBus
Master
3 x 10kΩ
RS0 RS1
SDA ^VCC
SCL
RESET
LED0
LED1
CAT9552
LED11
A2
LED12
A1
A0
V_SS
LED15
RS11
GPIOs
Notes: LED0 to LED11 are shown being used as LED drivers
LED12 to LED15 are used as standard GPIOs
© 2008 SCILLC. All rights reserved
1
Characteristics subject to change without notice
Doc. No. MD-9005 Rev B