PCA9531 Philips Semiconductors (Acquired by NXP), PCA9531 Datasheet - Page 2

• Manufacturer Part Number: PCA9531
• Description: 8-bit I2C Led Dimmerthe PCA9531 is an 8-bit i C And Smbus I/o Expander Optimized For Dimming Leds in 256 Discrete Steps For Red/green/blue (RGB) Color Mixing And Back Light Applications. The PCA9531 Contains an Internal Oscillator With Two User Progr
• Manufacturer: Philips Semiconductors (Acquired by NXP)

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ORDERING INFORMATION
Standard packing quantities and other packaging data is available at www.philipslogic.com/packaging.
I
2
Philips Semiconductors
2003 Nov 10
C is a trademark of Philips Semiconductors Corporation.
Eight LED drivers (on, off, flashing at a programmable rate)
Two selectable, fully programmable blink rates (frequency and
duty cycle) between 0.625 and 160 Hz (1.6 and 6.25 milliseconds)
256 brightness steps
Input/outputs not used as LED drivers can be used as regular
GPIOs
Internal oscillator requires no external components
I
Internal power-on reset
Noise filter on SCL/SDA inputs
Active low reset input
Eight open drain outputs directly drive LEDs to 25 mA
Edge rate control on outputs
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
Package offer: SO16, TSSOP16, HVQFN16
8-bit I
2
16-pin plastic TSSOP
16-pin plastic HVQFN
C interface logic compatible with SMBus
16-pin plastic SO
PACKAGES
2
C LED dimmer
TEMPERATURE RANGE
-40 to +85 °C
-40 to +85 °C
-40 to +85 °C
ORDER CODE
PCA9531PW
PCA9531BS
PCA9531D
2
DESCRIPTION
The PCA9531 is an 8-bit I
dimming LEDs in 256 discrete steps for Red/Green/Blue (RGB)
color mixing and back light applications.
The PCA9531 contains an internal oscillator with two user
programmable blink rates and duty cycles coupled to the output
PWM. The LED brightness is controlled by setting the blink rate high
enough (> 100 Hz) that the blinking can not be seen and then using
the duty cycle to vary the amount of time the LED is on and thus the
average current through the LED.
The initial setup sequence programs the two blink rates/duty cycles
for each individual PWM. From then on, only one command from the
bus master is required to turn individual LEDs ON, OFF, BLINK
RATE 1 or BLINK RATE 2. Based on the programmed frequency
and duty cycle, BLINK RATE 1 and BLINK RATE 2 will cause the
LEDs to appear at a different brightness or blink at periods up to 1.6
second. The open drain outputs directly drive the LEDs with
maximum output sink current of 25 mA per bit and 100 mA per
package.
To blink LEDs at periods greater than 1.6 second the bus master
(MCU, MPU, DSP, chipset, etc.) must send repeated commands to
turn the LED on and off as is currently done when using normal I/O
Expanders like the Philips PCF8574 or PCA9554. Any bits not used
for controlling the LEDs can be used for General Purpose Parallel
Input/Output (GPIO) expansion which provides a simple solution
when additional I/O is needed for ACPI power switches, sensors,
push-buttons, alarm monitoring, fans, etc.
The active low hardware reset pin (RESET) and Power On Reset
(POR) initializes the registers to their default state causing the bits
to be set high (LED off).
Three hardware address pins on the PCA9531 allow eight devices
to operate on the same bus.
TOPSIDE MARK
PCA9531D
PCA9531
9531
2
C & SMBus I/O expander optimized for
DRAWING NUMBER
SOT629-1
PCA9531
SOT109-1
SOT403-1
Product data