NCT5655Y

I/o Expanders Overview

The NCT5655Y is a 16-bit I2C-bus and SMBus GPIO controller manufactured by Nuvoton Technology Corporation. It provides 16 General Purpose Input/Output pins accessible via a two-wired serial interface compliant with I2C-bus/SMBus protocols. The device operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies from 0 Hz to 400 kHz. It features an open-drain interrupt output, polarity inversion registers, and configurable push-pull or open-drain outputs. The component is housed in a QFN-24 package (4x4 mm) and functions across an operating temperature range of -40 °C to +85 °C.

I/o Expanders Feature Summary

• Supports up to eight devices sharing the same bus through hardware address setting pins.
• Includes dedicated configuration for flashing LED outputs and PC beep generation.
• Provides interrupt notification capabilities triggered by input state transitions.

I/o Expanders Applications

• Expansion of general-purpose inputs and outputs for embedded systems
• Control interfaces for push buttons and sensor connections
• System event monitoring via interrupt signaling

I/o Expanders Procurement Notes

Verify the specific ordering suffix against official documentation to confirm the package type. The 'Y' suffix designates the QFN-24 package variant. Confirm RoHS compliance status and halogen-free requirements prior to procurement. Ensure the selected distributor sources directly from authorized channels to guarantee component authenticity and traceability.

I/o Expanders Selection Notes

Select the NCT5655Y when a compact surface-mount solution is required for I/O expansion. This model is appropriate for designs constrained by board space due to its small QFN footprint. Verify that the system power supply remains within the specified 2.3 V to 5.5 V range. Ensure the host controller supports standard I2C or SMBus communication speeds up to 400 kHz.

I/o Expanders Part Context

The NCT5655Y belongs to the NCT5655 series of I/O expanders produced by Nuvoton. It shares functional similarities with the NCT5655W but differs in physical packaging. While the W variant utilizes a TSSOP-24 package, the Y variant employs a QFN-24 form factor. Both models offer identical electrical specifications and pinout configurations for GPIO functionality.

I/o Expanders Replacement Considerations

The NCT5655W serves as a direct package alternative within the same product family. It maintains identical electrical characteristics and register maps. Substitution requires verification of mechanical fitment due to the difference between QFN and TSSOP footprints.

I/o Expanders FAQ

How many devices can share the same I2C bus?

Up to eight devices can share the same I2C bus by configuring the three address input pins (A0, A1, A2).

What is the default state of the GPIO pins upon reset?

Upon reset, all 16 I/O pins are configured as inputs with a weak pull-up to VDD.

Can the interrupt output be used for other functions?

Yes, the INT# pin can be reconfigured to function as an LED output or a BEEP output signal.