This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 2.3-V to 5.5-V VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)].
The PCA9535 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 Port 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 PCA9535 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 PCA9535 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.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
PCA9535 | SSOP (16) | 6.20 mm × 5.30 mm |
VQFN (16) | 4.00 mm × 4.00 mm | |
QFN (16) | 3.00 mm × 3.00 mm |