PCA9518: Expandable 5-channel I2C-bus hub

The PCA9518 is a BiCMOS integrated circuit intended for application in I²C-bus and SMBus systems.

While retaining all the operating modes and features of the I²C-bus system, it permits extension of the I²C-bus by buffering both the data (SDA) and the clock (SCL) lines, thus enabling virtually an unlimited number of buses of 400 pF.

The I²C-bus capacitance limit of 400 pF restricts the number of devices and bus length. Using the PCA9518 enables the system designer to divide the bus into an unlimited number of segments off of a hub where any segment to segment transition sees only one repeater delay and is multiple master capable on each segment.

Using multiple PCA9518 parts, any width hub (in multiples of five)1can be implemented using the expansion pins.

The PCA9518 is a wider voltage range (2.3 V to 3.6 V) version of the PCA9518 and also improves partial power-down performance, keeping I²C-bus I/O pins in high-impedance state when VDD is below 2.0 V.

A PCA9518 cluster cannot be put in series with a PCA9515/16 or with another PCA9518 cluster. Multiple PCA9518 devices can be grouped with other PCA9518 devices into any size cluster thanks to the EXPxxxn pins that allow the I²C-bus signals to be sent/received from/to one PCA9518 to/from another PCA9518 within the cluster. Since there is no direction pin, slightly different 'egal' low voltage levels are used to avoid lock-up conditions between the input and the output of individual repeaters in the cluster. A 'regular LOW' applied at the input of any of the PCA9518 devices will then be propagated as a 'buffered LOW' with a slightly higher value to all enabled outputs in the PCA9518 cluster. When this 'buffered LOW' is applied to a PCA9515 and PCA9516 or separate PCA9518 cluster (not connected via the EXPxxxn pins) in series, the second PCA9515 and PCA9516 or PCA9518 cluster will not recognize it as a 'regular LOW' and will not propagate it as a 'buffered LOW' again. The PCA9510/9511/9513/9514 and PCA9512 cannot be used in series with the PCA9515 and PCA9516 or PCA9518, but can be used in series with themselves since they use shifting instead of static offsets to avoid lock-up conditions.

1

PCA9518: Product Block Diagram
Outline 3d SOT360-1

2. The maximum system operating frequency may be less than 400 kHz because of the delays added by the repeater.

Data Sheets (1)
Name/DescriptionModified Date
Expandable 5-channel I2C-bus hub (REV 5.0) PDF (121.0 kB) PCA951802 Dec 2008
Application Notes (4)
Name/DescriptionModified Date
Level shifting techniques in I2C-bus design (REV 1.0) PDF (52.0 kB) AN1044120 Jun 2007
PCA954X FAMILY OF I²C / SMBus MULTIPLEXERS and SWITCHES (REV 2.0) PDF (807.0 kB) AN26201 Oct 2004
I2C manual (REV 1.0) PDF (4.2 MB) AN1021627 Mar 2003
I2C / SMBus Repeaters, Hubs and Expanders (REV 2.0) PDF (1.0 MB) AN25519 Dec 2002
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
PCA9600 demonstration board OM6293 (REV 1.0) PDF (130.0 kB) UM1032315 Dec 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; 20 leads; body width 4.4 mm (REV 1.0) PDF (304.0 kB) SOT360-108 Feb 2016
Packing (1)
Name/DescriptionModified Date
TSSOP20; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... (REV 4.0) PDF (225.0 kB) SOT360-1_11815 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
ProductStatus
PCA9518PWActive
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
PCA9518PWSOT360-1SSOP-TSSOP-VSO-WAVEReel 13" Q1/T1ActivePCA9518PW,118 (9352 724 03118)PCA9518PCA9518PWweek 3, 20050.03.04.19E411
Bulk PackActivePCA9518PW,112 (9352 724 03112)PCA9518PCA9518PWweek 3, 20050.03.04.19E411
Expandable 5-channel I2C-bus hub pca9518d
Level shifting techniques in I2C-bus design pca9685pw
PCA954X FAMILY OF I²C / SMBus MULTIPLEXERS and SWITCHES pca9516apw
I2C manual se98apw
I2C / SMBus Repeaters, Hubs and Expanders pca9600
I2C-bus specification and user manual pca9685pw
I2C-bus specification and user manual pca9685pw
PCA9600 demonstration board OM6293 pca9600
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
design_con_2003_tecforum_i2c_b_1 lm75a
PCA9518 IBIS model PCA9518PW
SOT360-1 LPC1112FDH20
SSOP-TSSOP-VSO-WAVE LPC1114FDH28
Reel 13" Q1/T1 LPC824M201JDH20
PCA9518
PCA9634