Philips Semiconductors Product data sheet
PCA9564Parallel bus to I
2
C-bus controller
2006 Sep 01
20
SPECIFIC APPLICATIONS
The PCA9564 is a parallel bus to I
2
C bus controller that is designed
to allow “smart” devices to interface with I
2
C or SMBus components,
where the “smart” device does not have an integrated I
2
C port and
the designer does not want to “bit-bang” the I
2
C port. The PCA9564
can also be used to add more I
2
C ports to “smart” devices, provide a
higher frequency, lower voltage migration path for the PCF8584 and
convert 8 bits of parallel data to a serial bus to avoid running
multiple traces across the PC board.
ADD I
2
C-BUS PORT
As shown in Figure 14, the PCA9564 converts 8-bits of parallel data
into a multiple master capable I
2
C port for microcontrollers,
microprocessors, custom ASICs, DSPs, etc., that need to interface
with I
2
C or SMBus components.
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC
CONTROL SIGNALS
8-BITS
PCA9564
SCL
SDA
SW02108
Figure 14. Adding I
2
C-bus Port Application
ADD ADDITIONAL I
2
C-BUS PORTS
The PCA9564 can be used to convert 8-bit parallel data into
additional multiple master capable I
2
C port as shown in Figure 15. It
is used if the microcontroller, microprocessor, custom ASIC, DSP,
etc., already have an I
2
C port but need one or more additional I
2
C
ports to interface with more I
2
C or SMBus components or
components that cannot be located on the same bus (e.g., 100 kHz
and 400 kHz slaves on different buses so that each bus can operate
at its maximum potential).
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC
CONTROL SIGNALS
8-BITS
PCA9564
SCL
SDA
SCL
SDA
SW02109
Figure 15. Adding Additional I
2
C-bus Ports Application
PCA8584 MIGRATION PATH
The PCA9564 does the same type of parallel to serial conversion as
the PCF8584. Although not footprint or code compatible, the
PCA9564 provides improvements such as:
1.Operating at 3.3 V and 2.5 V voltage nodes with 5 V tolerant I/Os
2.Allows interface with I
2
C or SMBus components at speeds up to
400 kHz.
3.Built-in oscillator provides a cost effective solution since the
external clock input is no longer required.
4.Parallel data can be exchanged at speeds up to 50 MHz allowing
the use of faster processors.
PCA9564
SCL
SDA
OSCILLATOR
PCF8584
SCL
SDA
CLOCK INPUT
2.3 – 3.6 V < 400 kHz
4.5 – 5.5 V < 100 kHz
SW02110
SUPPLY VOLTAGE FREQUENCY
Figure 16. PCF8584 Migration Path
CONVERT 8 BITS OF PARALLEL DATA INTO
I
2
C-BUS SERIAL DATA STREAM
Functioning as a slave transmitter, the PCA9564 can convert 8-bit
parallel data into a two-wire I
2
C data stream as is shown in
Figure 17. This would prevent having to run 8 traces across the
entire width of the PC board.
MICROCONTROLLER,
MICROPROCESSOR,
OR ASIC
CONTROL
SIGNALS
8-BITS
PCA9564
SCL
SDA
MASTER
SW02111
Figure 17. Converting Parallel to Serial Data Application
