NCA9539BYHP

I/o Expanders Overview

The NCA9539BYHP is a low-voltage 16-bit I²C and SMBus I/O expander manufactured by Nexperia, housed in an HWQFN24 package. It provides General Purpose Input/Output expansion with interrupt output, reset pin, and configuration registers for I²C-bus/SMBus applications. The device operates within a wide voltage range of 1.65 V to 5.5 V and supports Fast-mode clock frequencies up to 400 kHz. It features Schmitt-trigger inputs, noise filters, and 5 V tolerant I/Os. The component includes an open-drain active LOW interrupt output, a dedicated reset input, and internal power-on reset functionality. All I/O pins default to high-impedance inputs at power-up.

I/o Expanders Feature Summary

• Provides 16 bits of GPIO expansion with configurable direction via configuration registers
• Features an open-drain interrupt output triggered by any GPIO state change
• Includes a dedicated active-low reset pin for system initialization without power cycling
• Supports hardware-selectable slave addresses using two address pins

I/o Expanders Applications

• ACPI power switches
• Sensor interface expansion
• Push button and LED control systems
• Fan control circuits

I/o Expanders Procurement Notes

Verify the specific ordering suffix BYHP corresponds to the HWQFN24 package variant when sourcing components. Confirm that the intended application environment remains within the specified operating temperature range of -40 °C to +85 °C. Ensure proper pull-up resistor configurations are applied to the SCL, SDA, INT, and RESET lines as required by the bus protocol and device specifications.

I/o Expanders Selection Notes

Select this component when a design requires expanding microcontroller I/O capabilities over an I²C or SMBus interface while maintaining minimal interconnections. The HWQFN24 package offers a compact footprint suitable for space-constrained layouts. Consider the 5 V tolerance feature if interfacing with higher voltage logic levels despite the lower supply voltage operation. Verify that the maximum drive capability of 25 mA per pin meets the load requirements for connected peripherals.

I/o Expanders Part Context

The NCA9539 series serves as a parallel port expander for I²C-bus applications, allowing multiple devices to share the same bus through hardware address selection. The BYHP designation specifically identifies the HWQFN24 plastic thermal enhanced very thin Quad Flat package variant. This family of expanders simplifies system architecture by reducing the number of direct connections between the host controller and peripheral devices.

I/o Expanders Replacement Considerations

The NCA9539PWJ is a functional equivalent utilizing a TSSOP24 package instead of the HWQFN24 form factor. Both variants share identical electrical characteristics and register maps. Designers must evaluate mechanical fit and thermal dissipation requirements when substituting between package types.