Low-voltage 16-bit I²C and SMBus I/O expander with interrupt output and configuration registers

The NCA9555 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 and default pull-up resistors on GPIOs. 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, fan control etc. The NCA9555 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 NCA9555 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 NCA9555 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 default to 16 inputs
  • Open-drain active LOW interrupt output (INT)
  • 400 kHz Fast-mode I²C-bus
  • Internal power-on reset
  • Power-up with all channels configured as inputs with weak pull-up resistors
  • 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
  • Specified from -40 °C to +85 °C


Type numberProduct statusVCC (V)Logic switching levelsPower dissipation considerationsTamb (°C)Package name
NCA9555PWProduction1.65 - 5.5CMOSlow-40~85TSSOP24


Type numberPackagePackage informationReflow-/Wave solderingPackingStatusMarkingOrderable part number, (Ordering code (12NC))
Reel 13" Q1/T1ActiveNCA9555PWNCA9555PWJ
( 9356 912 97118 )

Environmental information

Type numberOrderable part numberChemical contentRoHSRHF-indicatorLeadfree conversion date
Quality and reliability disclaimer

Documentation (8)

File nameTitleTypeDate
NCA9555Low-voltage 16-bit I²C and SMBus I/O expander with interrupt output and configuration registersData sheet2022-12-01
nca9555NCA9555 IBIS modelIBIS model2023-01-09
NCA95XX_EVB_Software NCA95XX EVB GUISoftware2023-03-12
NCA95XX_Arduino_Sketches NCA95XX Arduino™ Sketch ExamplesSoftware2023-03-12
UM90016NCA95xx GPIO expander EVB (Arduino™ shield compatible)User manual2023-01-23
UM90017NCA95XX Evaluation Board: Quick-Start GuideUser manual2023-01-18
SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
SOT355-1plastic, thin shrink small outline package; 24 leads; 0.65 mm pitch; 7.8 mm x 4.4 mm x 1.1 mm bodyPackage information2022-06-22


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File nameTitleTypeDate
nca9555NCA9555 IBIS modelIBIS model2023-01-09

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