The NXP PCA9535PW,118 is a 16-bit I²C-bus and SMBus I/O expander in a 24-TSSOP package. It provides 16 push-pull I/O pins that can be configured as inputs or outputs, with a 400 kHz clock interface. An interrupt output (INT) signals the host when an input changes, reducing bus polling overhead. The POR (power-on reset) feature ensures the I/Os default to inputs on power-up, preventing unintended drive conflicts.
Output drive: 10 mA source, 25 mA sink per pin
Each I/O pin can source 10 mA or sink 25 mA, enough to drive LEDs, small relays, or logic-level loads directly. The push-pull output stage eliminates the need for external pull-up resistors on output pins, simplifying the BOM. The total package current limit should be observed when driving multiple outputs simultaneously — the per-pin figures are not additive across all 16 pins at full load.
It is ROHS3 compliant.