Active production — still a valid BOM line
The CY8C9540A-24PVXI: ROHS3 compliance is confirmed, clearing EU and global regulatory requirements without a separate exemption review.
40 I/O over a single I2C bus
This is a 40-pin I2C port expander that communicates at 100 kHz — the bus clock sets the throughput ceiling for reading or writing all 40 I/O lines in a single transaction cycle. Each I/O can sink 25 mA or source 10 mA, enough to drive indicator LEDs, optocoupler inputs, or small signal relays without external buffer transistors on every channel. Outputs are open-drain, so the expander can wire-OR multiple interrupt lines on the same bus node — useful in a multi-sensor panel where any device can flag the host.
On-chip blocks that save board space
Integrated EEPROM stores configuration and pin states across power cycles, eliminating an external serial EEPROM for non-volatile settings. The built-in POR (power-on reset) and WDT (watchdog timer) mean the expander self-resets on brownout and can monitor host health without a separate supervisor IC. PWM outputs on selected pins allow direct LED dimming or buzzer tone generation — no dedicated PWM controller needed for simple indicator loads.
Shipped in Tube format, so prototype and low-volume builds get the parts in a rigid carrier without reel fees.