PCA9550 Philips Semiconductors, PCA9550 Datasheet - Page 2

• Manufacturer Part Number: PCA9550
• Description: 2-bit I2C LED driver with programmable blink rates
• Manufacturer: Philips Semiconductors

FEATURES
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ORDERING INFORMATION
Standard packing quantities and other packaging data is available at www.philipslogic.com/packaging.
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Philips Semiconductors
2003 May 02
C is a trademark of Philips Semiconductors Corporation.
2 LED drivers (on, off, flashing at a programmable rate)
2 selectable, fully programmable blink rates (frequency and duty
cycle) between 0.15625 and 40 Hz (6.4 and 0.025 seconds)
Input/output not used as LED drivers can be used as regular
GPIOs
Internal oscillator requires no external components
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Internal power-on reset
Noise filter on SCL/SDA inputs
Active-LOW reset input
2 open drain outputs directly drive LEDs to 25 mA
Controlled edge rates to minimize ground bounce
No glitch on power-up
Supports hot insertion
Low stand-by current
Operating power supply voltage range of 2.3 V to 5.5 V
0 to 400 kHz clock frequency
ESD protection exceeds 2000 V HBM per JESD22-A114,
150 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 which
exceeds 100 mA
Packages offered: SO8, TSSOP8
2-bit I
programmable blink rates
2
8-Pin Plastic TSSOP
C-bus interface logic compatible with SMBus
8-Pin Plastic SO
PACKAGES
2
C LED driver with
TEMPERATURE RANGE
-40 to +85 °C
-40 to +85 °C
ORDER CODE
PCA9550DP
PCA9550D
2
DESCRIPTION
The PCA9550 LED Blinker blinks LEDs in I
applications where it is necessary to limit bus traffic or free up the
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of this device is the internal oscillator with two programmable blink
rates. To blink LEDs using normal I/O Expanders like the PCF8574
or PCA9554, the bus master must send repeated commands to turn
the LED on and off. This greatly increases the amount of traffic on
the I
LED Blinker instead requires only the initial set up command to
program BLINK RATE 1 and BLINK RATE 2 (i.e., the frequency and
duty cycle). From then on, only one command from the bus master
is required to turn each individual open drain output ON, OFF, or to
cycle at BLINK RATE 1 or BLINK RATE 2. Maximum output sink
current is 25 mA per bit and 50 mA per package.
Any bits not used for controlling the LEDs can be used for General
Purpose Parallel Input/Output (GPIO) expansion.
The active-LOW hardware reset pin (RESET) and Power On Reset
(POR) initializes the registers to their default state, all zeroes,
causing the bits to be set HIGH (LED off).
One hardware address pin on the PCA9550 allows two devices to
operate on the same bus.
PIN CONFIGURATION
PIN DESCRIPTION
2
NUMBER
C Master’s (MCU, MPU, DSP, chipset, etc.) timer. The uniqueness
PIN
2
C-bus and uses up one of the master’s timers. The PCA9550
1
2
3
4
5
6
7
8
TOPSIDE MARK
SYMBOL
Figure 1. Pin configuration
RESET
PCA9550
LED0
LED1
LED0
LED1
V
SDA
SCL
V
V
A0
9550
SS
A0
DD
SS
1
2
3
4
Address input 0
LED driver 0
LED driver 1
Supply ground
Active-LOW reset input
Serial clock line
Serial data line
Supply voltage
8
7
6
5
DRAWING NUMBER
2
C-bus and SMBus
V
SDA
SCL
RESET
FUNCTION
DD
SOT505-1
PCA9550
SOT96-1
Product data
SW00926