PCA9665_2 © NXP B.V. 2006. All rights reserved.
Product data sheet Rev. 02 — 7 December 2006 68 of 91
NXP Semiconductors PCA9665
Fm+ parallel bus to I2C-bus controller
10.3 Add additional I2C-bus ports

The PCA9665 can be used to convert 8-bit parallel data into additional multiple master

capable I2C-bus port as shown in Figure 34. It is used if the microcontroller,

microprocessor, custom ASIC, DSP, etc., already have an I2C-bus port but need one or

more additional I2C-bus ports to interface with more I2C-bus or SMBus components or

components that cannot be located on the same bus (e.g., 100kHz and 400 kHz slaves

on different buses so that each bus can operate at its maximum potential).

10.4 Convert 8 bits of parallel data into I2C-bus serial data stream

Functioning as a slave transmitter, the PCA9665 can convert 8-bit parallel data into a

two-wire I2C-bus data stream as is shown inFigure 35. This would prevent having to run

8 traces across the entire width of the printed-circuit board.

Fig 33. Adding I2C-bus port application
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC
control signals
8 bits data
PCA9665 SDA
SCL
002aab036
Fig 34. Adding additional I2C-bus ports application
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC control signals
8 bits data
PCA9665 SDA
SCL
002aab037
SDA
SCL

Fig 35. Converting parallel to serial data application

control signals
8 bits data
PCA9665
SDA
SCL
002aab039
MASTER
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC