PCA9555_10 Datasheet, PDF (1/35 Pages) Texas Instruments – REMOTE 16-BIT I2C AND SMBus I/O EXPANDER WITH INTERRUPT OUTPUT AND CONFIGURATION REGISTERS

PCA9555
www.ti.com ......................................................................................................................................................... SCPS131E – AUGUST 2005 – REVISED MAY 2008
REMOTE 16-BIT I²C AND SMBus I/O EXPANDER
WITH INTERRUPT OUTPUT AND CONFIGURATION REGISTERS
FEATURES
1
• Low Standby-Current Consumption of
1 µA Max
• I²C to Parallel Port Expander
• Open-Drain Active-Low Interrupt Output
• 5-V Tolerant I/O Ports
• Compatible With Most Microcontrollers
• 400-kHz Fast I²C Bus
• Address by Three Hardware Address Pins for
Use of up to Eight Devices
DB, DBQ, DGV, DW, OR PW PACKAGE
(TOP VIEW)
• Polarity Inversion Register
• Latched Outputs With High-Current Drive
Capability for Directly Driving LEDs
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
RGE PACKAGE
(TOP VIEW)
INT ¹
A1 ²
A2 ³
P00 ⁴
P01 ⁵
P02 ⁶
P03 ⁷
P04 ⁸
P05 ⁹
P06 ¹⁰
P07 ¹¹
GND ¹²
24 _VCC
23 _SDA
22 _SCL
21 _A0
20 _P17
19 _P16
18 _P15
17 _P14
16 _P13
15 _P12
14 _P11
13 _P10
24 23 22 21 20 19
P00 1
18 A0
P01 2
17 P17
P02 3
16 P16
P03 4
15 P15
P04 5
14 P14
P05 6
13 P13
7 8 9 10 11 12
DESCRIPTION/ORDERING INFORMATION
This 16-bit I/O expander for the two-line bidirectional bus (I²C) is designed for 2.3-V to 5.5-V V_CC operation. It
provides general-purpose remote I/O expansion for most microcontroller families via the I²C interface [serial clock
(SCL), serial data (SDA)].
The PCA9555 consists of two 8-bit Configuration (input or output selection), Input Port, Output Port, and Polarity
Inversion (active high or active low operation) registers. At power on, the I/Os are configured as inputs. The
system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for
each input or output is kept in the corresponding Input or Output register. The polarity of the Input Port register
can be inverted with the Polarity Inversion register. All registers can be read by the system master.
The system master can reset the PCA9555 in the event of a timeout or other improper operation by utilizing the
power-on reset feature, which puts the registers in their default state and initializes the I²C/SMBus state machine.
The PCA9555 open-drain interrupt (INT) output is activated when any input state differs from its corresponding
Input Port register state and is used to indicate to the system master that an input state has changed.
INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the
remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via
the I²C bus. Thus, the PCA9555 can remain a simple slave device.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2008, Texas Instruments Incorporated