The NCA9534B is a 16-pin CMOS device that provides 8-bit general purpose parallel I2C bus count input/output GPIO expansion. It and ACPI power switches, sensors, pushbuttons, LEDs and fans provide a simple solution to the need for additional I/O ports for applications such as the NCA9534B consists of an 8-bit configuration (input or output selection). Input, Output, and Polarity Reversal (active high or active low) registers. By writing to the I/O configuration bits, the system host can enable the I/Os as inputs or outputs. The data for each input or output is stored in the corresponding input or output register. The polarity of the read registers can be reversed with the polarity reversal register. The system host can read all registers. When the state of any input is different from the state of its corresponding input port register, the NCA9534B open drain interrupt output is activated and is used to indicate to the system host device that the output state has changed. A power-on reset sets the registers to their default values and initializes the device state machine. Three hardware pins (A0, A1, A2) change fixed I2C bus addresses and allow up to eight devices to share the same I2C bus.
• I2C to Parallel Port Expander
• Operating power supply voltage range of 1.65 V to 5.5 V
• Low standby current
• Open-drain active-low interrupt output
• 5.5 V tolerant, 8 I/O ports which default to input mode
• Compatible with most microcontrollers
• Up to 400 kHz clock frequency
• Noise filter on SCL/SDA inputs
• Polarity Inversion register
• Internal power-on reset
• No glitch on power-up
• Address by three hardware address pins for use of up to
eight devices
• Latched outputs with high-current drive capability for
directly driving LEDs
• Latch-up performance exceeds 100 mA per JESD 78,
class II
• ESD protection exceeds JESD 22: 2000 V HBM, 200 V MM,
and 1000 V CDM
• GPIO expansion for I2C-bus applications
• Servers, personal computers, personal electronics
• Routers (Telecom Switching Equipment)
• Products with GPIO-Limited processors
