Skip to main content
Log in
NXP Semiconductors PCAL6524HEHP — Circuit Protection

PCAL6524HEHP I2C GPIO Expander, 24 I/O, 1 MHz, 1.65V-5.5V

MPNPCAL6524HEHP
End of Life

NXP PCAL6524HEHP, 24-bit I2C-bus GPIO expander, 1 MHz clock frequency, 1.65V to 5.5V supply voltage, open-drain and push-pull outputs, interrupt output, POR, -40°C to 85°C, 32-HUQFN (5x5) package.

$2.05Ref. price · indicative, final on quote
NXP Semiconductors PCAL6524HEHP datasheet (PDF)
Packaging32-UFQFN Exposed Pad
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

PCAL6524HEHP specifications
ParameterValue
Output typeOpen Drain, Push-Pull
MountingSurface Mount
Voltage1.65V ~ 5.5V
Frequency1 MHz
InterfaceI²C
Operating temperature-40°C ~ 85°C
PackageTape & Reel (TR); Cut Tape (CT)
FeaturesPOR
Number of i (O)24
Case32-UFQFN Exposed Pad
Interrupt outputYes

Product details

POR and interrupt — two features that save firmware cycles

The power-on reset (POR) forces all registers to their default state when VDD rises, so the I/O pins start as inputs — no glitch on a relay coil or LED at power-up. The interrupt output (INT) asserts low when any input pin changes state relative to the last read. The host sees the interrupt, reads the input port register, and clears the flag. This beats polling 24 pins every loop, especially when the expander is on a slower I²C bus.

ROHS3 compliant.

Frequently asked questions

What is the interrupt feature on PCAL6524HEHP and how does it work?

The interrupt output (INT) asserts low when any input pin changes state from the last read. The host reads the input port register to identify the changed pin, which clears the interrupt. This allows event-driven firmware instead of polling all 24 I/O.

Can PCAL6524HEHP run at 5V?

Yes, the supply range extends to 5.5V, so 5V operation is within spec.

How does PCAL6524HEHP compare to PCA9535?

The PCA9535 is a 16-bit I²C GPIO expander with a 400 kHz max clock and no interrupt output. The PCAL6524HEHP offers 24 I/O, a 1 MHz clock, an interrupt output, and a wider 1.65V to 5.5V supply range versus the PCA9535's 2.3V to 5.5V. If you need more I/O, higher bus speed, or interrupt capability, the PCAL6524HEHP is the step-up.