1. General description
The PCA9505/PCA9506 provide 40-bit parallel input/output (I/O) port expansion for
I
2
C-bus applications organized in 5 banks of 8 I/Os. At 5 V supply voltage, the outputs are
capable of sourcing 10 mA and sinking 15 mA with a total package load of 600 mA to
allow direct driving of 40 LEDs. Any of the 40 I/O ports can be configured as an input or
output. Output ports are totem-pole and their logic state changes at the Acknowledge
(bank change). The PCA9505 is identical to the PCA9506 except that it includes 100 kΩ
internal pull-up resistors on all the I/Os. The PCA9506 does not include the internal
pull-ups on the I/Os to reduce power consumption when used as outputs or when the
input is driven by a push-pull driver.
The device can be configured to have each input port to be masked in order to prevent it
from generating interrupts when its state changes and to have the I/O data logic state to
be inverted when read by the system master.
An open-drain interrupt (INT
) output pin allows monitoring of the input pins and is asserted
each time a change occurs in one or several input ports (unless masked).
The Output Enable (OE
) pin 3-states any I/O selected as an output and can be used as an
input signal to blink or dim LEDs (PWM with frequency > 80 Hz and change duty cycle).
The internal Power-On Reset (POR) or hardware reset (RESET
) pin initializes the 40 I/Os
as inputs. Three address select pins configure one of 8 slave addresses.
The PCA9506 is available in 56-pin TSSOP and HVQFN packages, while the PCA9505 is
available only in a TSSOP package. They are both specified over the −40 °Cto+85°C
industrial temperature range.
2. Features and benefits
Standard mode (100 kHz) and Fast mode (400 kHz) compatible I
2
C-bus serial
interface
2.3 V to 5.5 V operation with 5.5 V tolerant I/Os
40 configurable I/O pins that default to inputs at power-up
PCA9505 includes 100 kΩ internal pull-up resistors on all the I/Os
Outputs:
Totem-pole (10 mA source, 15 mA sink) with controlled edge rate output structure
Active LOW output enable (OE
) input pin 3-states all outputs
Output state change on Acknowledge
Open-drain active LOW interrupt (INT
) output pin allows monitoring of logic level
change of pins programmed as inputs
PCA9505/06
40-bit I
2
C-bus I/O port with RESET, OE and INT
Rev. 4 — 3 August 2010 Product data sheet
