PCA9556PW: Octal SMBus and I2C registered interface

The PCA9556 is a silicon CMOS circuit which provides parallel input/output expansion for SMBus applications. The PCA9556 consists of an 8-bit input port register, 8-bit output port register, and an SMBus interface. It has low current consumption and a high impedance open drain output pin, I/O0.

The SMBus system master can reset the PCA9556 in the event of a timeout by asserting a LOW on the reset input. The SMBus system master can also invert the PCA9556 inputs by writing to the active HIGH polarity inversion bits. Finally, the system master can enable the PCA9556?s I/Os as either inputs or outputs by writing to the configuration register.

The power-on reset puts the registers in their default state and initializes the SMBus state machine. The RESET pin causes the same reset/initialization to occur without depowering the part.

The PCA9557 8-bit I²C SMBus I/O port with reset is the higher performance pin-for-pin replacement for the PCA9556.

PCA9556PW: Product Block Diagram
Outline 3d SOT403-1

ESD protection exceeds 2000 V HBM per JESD22-A114,

200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101

Data Sheets (1)
Name/DescriptionModified Date
Octal SMBus and I2C registered interface (REV 6.0) PDF (97.0 kB) PCA955628 Mar 2002
Application Notes (2)
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
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 (1)
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
Package Information (1)
Name/DescriptionModified Date
plastic thin shrink small outline package; 16 leads; body width 4.4 mm (REV 1.0) PDF (300.0 kB) SOT403-108 Feb 2016
Packing (1)
Name/DescriptionModified Date
TSSOP16; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... (REV 1.0) PDF (218.0 kB) SOT403-1_11808 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 (1)
Name/DescriptionModified Date
Footprint for wave soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-WAVE08 Oct 2009
IBIS Model
Ordering Information
ProductStatusNo of bitsVDD [min] (V)VDD [max] (V)Over volt tolerantNo of suppliesStandby current [typ] (µA)Max Sink Current per bit (mA)Max Sink Current, per package (mA)Source Current per bit (mA)Interrupt output pinReset input pinOutput modeInput mode: invert optionInternal pull-up resistor per bit (kOhm)I2C-bus (kHz)Footprint body and leads (mm2)Package namePackage versionOperating Temperature (Cel)No of AddressesRemark
PCA9556PWNot Recommended for New Design835.512510804YTotem Pole/Open DrainY10033.66TSSOP16SOT403-1-40~858Only bit 0 is open drain
PCA9556PW/GNo Longer Manufactured835.512510804YTotem Pole/Open DrainY10033.66TSSOP16SOT403-1-40~858Only bit 0 is open drain
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateMSLMSL LF
PCA9556PWSOT403-1SSOP-TSSOP-VSO-WAVEReel 13" Q1/T1ActivePCA9556PW,118 (9352 628 99118)PCA9556PCA9556PWweek 48, 200411
Bulk PackActivePCA9556PW,112 (9352 628 99112)PCA9556PCA9556PWweek 48, 200411