General description
The NCA9535 provides 16 bits of General Purpose Input/Output (GPIO) expansion for
I²C-bus/SMBus applications. It is designed for a wide voltage range of 1.65 V to 5.5 V with
interrupt. Nexperia GPIO expanders provide an elegant solution when additional IOs are
needed while keeping the interconnections to a minimum, for example, in ACPI power switches,
sensors, push buttons, LEDs and fan control. The NCA9535 contains a set of 8 bit input, output,
configuration and polarity inversion registers. At power up all IOs default to inputs. Each IO can be
configured as either input or output by changing the corresponding bit in the configuration register.
The data for each input or output is stored in the corresponding input or output register. The polarity
inversion register can be programmed to invert the polarity of the input register. The NCA9535
has an open-drain interrupt output which is activated when any one of the GPIO changes from its
corresponding input port register state. The power on reset sets the registers to default values and
initializes the device state machine. The NCA9535 has three address pins A0, A1 and A2 which
can be used to configure the I²C bus slave address of the device. It allows up-to eight devices to
share the same I²C-bus/SMBus.

Features and benefits
• I²C-bus to parallel port expander
• Operating power supply voltage range of 1.65 V to 5.5 V
• Low standby current consumption:
• 2.5 μA (maximum)
• Schmitt-trigger action allows slow input transition and better switching noise immunity at the
SCL and SDA inputs
• Vhys = 0.10 × VCC (typical)
• Noise filter on SCL and SDA inputs
• 5 V tolerant I/Os
• 16 I/O pins which power up configured in input state
• Open-drain active LOW interrupt output (INT)
• 400 kHz Fast-mode I²C-bus
• Internal power-on reset
• No glitch on power-up
• Latched outputs with 25 mA drive maximum capability for directly driving LEDs
• Latch-up performance exceeds 100 mA per JESD78, Class II
• ESD protection:
• HBM ANSI/ESDA/JEDEC JS-001 Class 2 exceeds 2000 V
• CDM ANSI/ESDA/JEDEC JS-002 Class C3 exceeds 1000 V
• Package offered: TSSOP24
• Specified from -40 °C to +85 °C