DESCRIPTION
The PCA9556 is a silicon CMOS circuit which provides parallel input/output expansion for SMBus applications.

FEATURES
• SMBus compliance with fixed 3.3V voltage levels
• Operating power supply voltage range of 3.0 V – 5.5 V
• Active high polarity inverter register
• Each I/O is configurable as an input or output
• Active low reset pin
• Low leakage current on power-down
• Noise filter on SCL/SDA inputs
• No glitch on power-up
• Internal power-on reset
• 8 I/O pins which default to 8 inputs
• High impedance open drain on I/O0
• ESD protection exceeds 2000 V HBM per JESD22-A114,
    200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101
• Latch-up testing is done to JESDEC Standard JESD78 which
    exceeds 100 mA