Philips Semiconductors

Preliminary data

PCA9530

2

2002 Dec 12

FEATURES

cycle) between 0.625 and 160 Hz (1.6 seconds and

6.25 milliseconds)

GPIOs

150 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101

exceeds 100 mA

DESCRIPTION

The PCA9530 is a 2-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 PCA9530 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 50 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,

pushbuttons, alarm monitoring, fans, etc.

The active low hardware reset pin (RESET) and Power On Reset

(POR) initialize the registers to their default state causing the bits to

be set high (LED off).

One hardware address pin on the PCA9530 allows two devices to

operate on the same bus.

1

2

3

45

6

7

8

A0

LED0

LED1

SDA

SCL

RESET

SW00926

Figure 1. Pin configuration

PIN DESCRIPTION

PIN

NUMBER

SYMBOL

FUNCTION

1

A0

Address input 0

2

LED0

LED driver 0

3

LED1

LED driver 1

4

Supply ground

5

RESET

Active low reset input

6

SCL

Serial clock line

7

SDA

Serial data line

8

Supply voltage

ORDERING INFORMATION

PACKAGES

TEMPERATURE RANGE

ORDER CODE

TOPSIDE MARK

DRAWING NUMBER

8-Pin Plastic SO

-40 to +85

°C

PCA9530D

PCA9530

SOT96-1

8-Pin Plastic TSSOP

-40 to +85

°C

PCA9530DP

9530

SOT505-1

Standard packing quantities and other packaging data is available at www.philipslogic.com/packaging.