PCA9555PW,118

• 16 Configurable I/O Lines Arranged as Two 8-Bit Ports
• I2C-Bus and SMBus interface, 400 K Hz Maximum Bus Speed
• 2.3 V to 5.5 V Supply range; 3 V Nominal Operating Voltage
• 135 Microamp Nominal Supply Current
• 24-Pin TSSOP package, 0.65 Mm Terminal pitch, 1.1 Mm Maximum Height
• -40°C to 85°C Operating range; RoHS compliant, Declared as Containing REACH SVHC Substances

The NXP Semiconductors PCA9555PW,118 is a 16-bit I2C-bus and SMBus I/O expander in a 24-pin TSSOP package, arranged as two 8-bit ports for 16 configurable I/O lines. It operates from a 2.3 V to 5.5 V supply at up to 400 k Hz bus speed and draws roughly 135 microamps of supply current. The PCA9555PW,118 is rated for -40°C to 85°C with a 125°C maximum junction temperature, is RoHS compliant, and ships on tape and reel.

An I/O expander adds general-purpose inputs and outputs to a system over a two-wire I2C bus when the host microcontroller has run out of pins, which is common once a design adds buttons, LEDs, relays, and status lines late in development. Sixteen bidirectional lines behind one address let a designer add a full front panel or control block without changing the processor. Typical uses include industrial control panels, networking equipment, point-of-sale terminals, appliances, and test fixtures. Because the PCA9555 function is widely second-sourced, embedded designers and OEM buyers also use it as a low-risk, long-availability building block.