PCA9555: 16-bit I2C-bus and SMBus I/O port with interrupt

The PCA9555 is a 24-pin CMOS device that provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion for I²C-bus/SMBus applications and was developed to enhance the NXP Semiconductors family of I²C-bus I/O expanders. The improvements include higher drive capability, 5 V I/O tolerance, lower supply current, individual I/O configuration, and smaller packaging. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push buttons, LEDs, fans, etc.

The PCA9555 consists of two 8-bit Configuration (Input or Output selection); Input, Output and Polarity Inversion (active HIGH or active LOW operation) registers. The system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each Input or Output is kept in the corresponding Input or Output register. The polarity of the read register can be inverted with the Polarity Inversion register. All registers can be read by the system master. Although pin-to-pin and I²C-bus address compatible with the PCF8575, software changes are required due to the enhancements, and are discussed in Application Note AN469.

The PCA9555 open-drain interrupt 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. The power-on reset sets the registers to their default values and initializes the device state machine.

Three hardware pins (A0, A1, A2) vary the fixed I²C-bus address and allow up to eight devices to share the same I²C-bus/SMBus. The fixed I²C-bus address of the PCA9555 is the same as the PCA9554, allowing up to eight of these devices in any combination to share the same I²C-bus/SMBus.

PCA9555: Product Block Diagram
Outline 3d SOT137-1
Data Sheets (1)
Name/DescriptionModified Date
16-bit I2C-bus and SMBus I/O port with interrupt (REV 8.0) PDF (539.0 kB) PCA955522 Oct 2009
Application Notes (5)
Name/DescriptionModified Date
PCA9500/PCA9501 provides simple card maintenance and control using I²C-bus (REV 1.0) PDF (90.0 kB) AN25623 Mar 2009
Level shifting techniques in I2C-bus design (REV 1.0) PDF (52.0 kB) AN1044120 Jun 2007
I2C/SMBus general purpose I/O expanders (REV 2.0) PDF (294.0 kB) AN46920 Jan 2005
LED dimmer demoboard (REV 1.0) PDF (392.0 kB) AN1031511 Jan 2005
I2C 2002-1A Evaluation Board (REV 2.0) PDF (2.2 MB) AN1014626 Feb 2003
Users Guides (4)
Name/DescriptionModified Date
I2C-bus specification and user manual (REV 6.0) PDF (1.4 MB) UM1020428 Apr 2014
I2C-bus specification and user manual (REV 5.0) PDF (1.6 MB) UM10204_JA03 Apr 2013
PCA9698 demonstration board OM6281 (REV 1.0) PDF (558.0 kB) UM1026726 Sep 2008
I2C Demonstration Board 2005-1 Quick Start Guide (REV 1.0) PDF (261.0 kB) UM1020613 Jun 2006
Brochures (5)
Name/DescriptionModified Date
NXP® I2C-bus solutions 2014: Smart, simple solutions for the 12 most common design concerns (REV 1.0) PDF (3.5 MB) 7501754001 Aug 2014
Versatile, easy-to-use GPIO expanders; NXP® 4/8/16-bit I2C/SMBus GPIO expanders PCA9536/54/54A/55 (REV 1.0) PDF (319.0 kB) 7501653501 Aug 2008
Evaluate the I2C-bus with a comprehensive kit; NXP® I2C 2002-1A evaluation board kits OM6285 and OM6278 (REV 1.0) PDF (1.8 MB) 7501653101 Jul 2008
Create smarter, more efficient white goods; An industry-leading portfolio of cost-effective, power-saving solutions for... (REV 1.0) PDF (1.1 MB) 7501654301 Jun 2008
Low-power GPIO expanders for portable applications; NXP® 8/16-bit I2C/SMBus GPIO expanders... (REV 1.0) PDF (239.0 kB) 7501602001 Jun 2007
Package Information (5)
Name/DescriptionModified Date
plastic small outline package; 24 leads; body width 7.5 mm (REV 1.0) PDF (379.0 kB) SOT137-108 Feb 2016
plastic shrink small outline package; 24 leads; body width 5.3 mm (REV 1.0) PDF (349.0 kB) SOT340-108 Feb 2016
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 thin quad flat package; no leads; 24 terminals; body 4 x 4 x 0.85 mm (REV 1.0) PDF (202.0 kB) SOT616-108 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 (5)
Name/DescriptionModified Date
HVQFN24; Reel pack; SMD, 13", Q2/T3 Turned product orientation Orderable part number ending ,128 or HP Ordering code... (REV 1.0) PDF (185.0 kB) SOT616-1_12816 Jul 2014
HVQFN24; reel pack; standard product orientation; 12NC ending 118 (REV 1.0) PDF (196.0 kB) SOT616-1_11816 Jan 2014
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
SO24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering... (REV 4.0) PDF (235.0 kB) SOT137-1_11812 Apr 2013
SSOP24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... (REV 1.0) PDF (230.0 kB) SOT340-1_11805 Apr 2013
Reports or Presentations (1)
Name/DescriptionModified Date
design_con_2003_tecforum_i2c_b_1 (REV 0.1) PDF (4.2 MB) DESIGN_CON_2003_TECFORUM_I2C_B_127 Jan 2003
Supporting Information (3)
Name/DescriptionModified Date
Footprint for wave soldering (REV 1.0) PDF (8.0 kB) SO-SOJ-WAVE08 Oct 2009
Footprint for reflow soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-REFLOW08 Oct 2009
Footprint for wave soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-WAVE08 Oct 2009
Design Support
IBIS Model
Ordering Information
ProductStatus
PCA9555PWActive
PCA9555DBActive
PCA9555HFActive
PCA9555BSActive
PCA9555DActive
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
PCA9555DSOT137-1SO-SOJ-WAVEReel 13" Q1/T1ActivePCA9555D,118 (9352 695 67118)PCA9555DPCA9555Dweek 11, 20050.02.05E811
Bulk PackActivePCA9555D,112 (9352 695 67112)PCA9555DPCA9555Dweek 11, 20050.02.05E811
PCA9555DBSOT340-1SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE
SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1ActivePCA9555DB,118 (9352 695 68118)PCA9555PCA9555DBweek 12, 20050.02.05E811
Bulk PackActivePCA9555DB,112 (9352 695 68112)PCA9555PCA9555DBweek 12, 20050.02.05E811
PCA9555BSSOT616-1Reel 13" Q2/T3ActivePCA9555BSHP (9352 720 04128)9555PCA9555BSAlways Pb-free0.02.05E811
Reel 13" Q1/T1ActivePCA9555BS,118 (9352 720 04118)9555PCA9555BSAlways Pb-free0.02.05E811
PCA9555PWSOT355-1SSOP-TSSOP-VSO-WAVEReel 13" Q1/T1ActivePCA9555PW,118 (9352 695 69118)PCA9555PCA9555PWweek 47, 20040.02.05E811
Bulk PackActivePCA9555PW,112 (9352 695 69112)PCA9555PCA9555PWweek 47, 20040.02.05E811
PCA9555PW/DGSOT355-1SSOP-TSSOP-VSO-WAVEReel 13" Q1/T1WithdrawnPCA9555PW/DG,118 (9352 869 39118)PCA9555Always Pb-free0.02.05E811
PCA9555HFSOT994-1Reel 13" Q1/T1ActivePCA9555HF,118 (9352 844 58118)P55HPCA9555HFAlways Pb-free0.02.05E811
16-bit I2C-bus and SMBus I/O port with interrupt pca9555
PCA9500/PCA9501 provides simple card maintenance and control using I²C-bus PCA9553
Level shifting techniques in I2C-bus design pca9685pw
I2C/SMBus general purpose I/O expanders pcf8575ts
LED dimmer demoboard PCA9533
I2C 2002-1A Evaluation Board lm75a
I2C-bus specification and user manual pca9685pw
I2C-bus specification and user manual pca9685pw
PCA9698 demonstration board OM6281 PCA9553
I2C Demonstration Board 2005-1 Quick Start Guide pca9685pw
NXP® I2C-bus solutions 2014: Smart, simple solutions for the 12 most common design concerns pca9685pw
Versatile, easy-to-use GPIO expanders; NXP® 4/8/16-bit I2C/SMBus GPIO expanders PCA9536/54/54A/55 pcf8570p
Evaluate the I2C-bus with a comprehensive kit; NXP® I2C 2002-1A evaluation board kits OM6285 and OM6278 lm75a
Create smarter, more efficient white goods; An industry-leading portfolio of cost-effective, power-saving solutions for... PMEG6010CE_AUTOMOTIVE
Low-power GPIO expanders for portable applications; NXP® 8/16-bit I2C/SMBus GPIO expanders... pcf8570p
design_con_2003_tecforum_i2c_b_1 lm75a
Expert mode sample code for 16-bit Totem Pole PCAL9555APW
PCA9555 IBIS model PCA9555BS
PCA9555 IBIS model PCA9555HF
PCA9555 IBIS model PCA9555PW
plastic small outline package; 24 leads; body width 7.5 mm 74LVC4245A_Q100
Footprint for wave soldering NPIC6C596A_Q100
SO24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering... 74LVC4245A_Q100
plastic shrink small outline package; 24 leads; body width 5.3 mm tda9886ts
Footprint for reflow soldering 74HC_T_595_Q100
SSOP24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... tda9886ts
plastic thermal enhanced very thin quad flat package; no leads; 24 terminals; body 4 x 4 x 0.85 mm TFF1007HN
HVQFN24; Reel pack; SMD, 13", Q2/T3 Turned product orientation Orderable part number ending ,128 or HP Ordering code... pca9548a
HVQFN24; reel pack; standard product orientation; 12NC ending 118 TFF1007HN
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
PCA9555
PCA9552
74LVC4245A
TFF11152HN
SA639DH
PCAL9555A