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 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.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
PCA9555 | SSOP (24) DB | 8.20 mm × 5.30 mm |
SSOP (24) DBQ | 8.65 mm × 3.90 mm | |
TVSOP (24) DGV | 5.00 mm x 4.40 mm | |
SOIC (24) DW | 15.4 mm x 7.50 mm | |
SSOP (24) PW | 7.80 mm x 4.40 mm | |
VQFN (24) RGE | 4.00 mm x 4.00 mm |
Changes from Revision I (April 2019) to Revision J (March 2021)
Changes from Revision H (April 2019) to Revision I (April 2019)
Changes from Revision G (March 2018) to Revision H (April 2019)
Changes from Revision F (June 2014) to Revision G (March 2018)
Changes from Revision E (May 2008) to Revision F (June 2014)