PCAL9535A: Low-voltage 16-bit I²C-bus I/O port with interrupt and Agile I/O

The PCAL9535A is a low-voltage 16-bit General Purpose Input/Output (GPIO) expander with interrupt and reset for I²C-bus/SMBus applications. NXP I/O expanders provide a simple solution when additional I/Os are needed while keeping interconnections to a minimum, for example, in ACPI power switches, sensors, push buttons, LEDs, fan control, etc.

In addition to providing a flexible set of GPIOs, the wide VDD range of 1.65 V to 5.5 V allows the PCAL9535A to interface with next-generation microprocessors and microcontrollers where supply levels are dropping down to conserve power.

The PCAL9535A contains the PCA9535 register set of four pairs of 8-bit Configuration, Input, Output, and Polarity Inversion registers, and additionally, the PCAL9535A has Agile I/O, which are additional features specifically designed to enhance the I/O. These additional features are: programmable output drive strength, latchable inputs, programmable pull-up/pull-down resistors, maskable interrupt, interrupt status register, programmable open-drain or push-pull outputs.

The PCAL9535A is a pin-to-pin replacement to the PCA9535 and PCA9535A, however, the PCAL9535A powers up with all I/O interrupts masked. This mask default allows for a board bring-up free of spurious interrupts at power-up.

The PCAL9535A open-drain interrupt (INT) output is activated when any input state differs from its corresponding Input Port register state and is used to indicate to the system master that an input state has changed.

INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I²C-bus. Thus, the PCAL9535A can remain a simple slave device.

The device outputs have 25 mA sink capabilities for directly driving LEDs while consuming low device current.

The power-on reset sets the registers to their default values and initializes the device state machine.

Three hardware pins (A0, A1, A2) select the fixed I²C-bus address and allow up to eight devices to share the same I²C-bus/SMBus.

Outline 3d SOT355-1
Data Sheets (1)
Name/DescriptionModified Date
Low-voltage 16-bit I2C-bus I/O port with interrupt and Agile I/O (REV 2.0) PDF (2.6 MB) PCAL9535A23 Jan 2015
Application Notes (1)
Name/DescriptionModified Date
Low Voltage Agile I/O GPIO Input/Output Characteristics (REV 1.0) PDF (443.0 kB) AN1149615 Aug 2014
Package Information (2)
Name/DescriptionModified Date
plastic thin shrink small outline package; 24 leads; body width 4.4 mm (REV 1.0) PDF (353.0 kB) SOT355-108 Feb 2016
plastic thermal enhanced very very thin quad flat package; no leads; 24 terminals; body 4 x 4 x 0.75 mm (REV 1.0) PDF (213.0 kB) SOT994-108 Feb 2016
Packing (2)
Name/DescriptionModified Date
HWQFN24; Reel pack, SMD, 13" Q2/T3 standard product orientation Orderable part number ending ,128 or... (REV 1.1) PDF (190.0 kB) SOT994-1_12815 Jul 2016
TSSOP24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... (REV 4.1) PDF (227.0 kB) SOT355-1_11815 Apr 2013
Supporting Information (1)
Name/DescriptionModified Date
Footprint for wave soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-WAVE08 Oct 2009
Design Support
Ordering Information
ProductStatus
PCAL9535AHFActive
PCAL9535APWActive
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
PCAL9535APWSOT355-1SSOP-TSSOP-VSO-WAVEReel 13" Q1/T1ActivePCAL9535APW,118 (9352 980 94118)PCAL9535APCAL9535APWAlways Pb-free0.04.02.5E811
PCAL9535AHFSOT994-1Reel 13" Q2/T3ActivePCAL9535AHF,128 (9352 980 92128)L35APCAL9535AHFAlways Pb-free0.04.02.5E811
Low-voltage 16-bit I2C-bus I/O port with interrupt and Agile I/O pcal9535a
Low Voltage Agile I/O GPIO Input/Output Characteristics pcal9555a
HWQFN24; Reel pack, SMD, 13" Q2/T3 standard product orientation Orderable part number ending ,128 or... pcal9555a
Expert mode sample code for 16-bit Totem Pole PCAL9555APW
plastic thin shrink small outline package; 24 leads; body width 4.4 mm 74LVC4245A_Q100
SSOP-TSSOP-VSO-WAVE LPC1114FDH28
TSSOP24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... 74LVC4245A_Q100
plastic thermal enhanced very very thin quad flat package; no leads; 24 terminals; body 4 x 4 x 0.75 mm pcal9555a
SA639DH
PCAL9555A