Optical Mouse Transmitter
System Overview
DRM050 — Rev 0
Designer Reference Manual
MOTOROLA
Optical Mouse Transmitter
19
3.2.3 RF Transmission
The data from the MCU will be transferred to the baseband IC for parallel
to serial packet conversion as well as error checking. The encoded data
will be passed to the RF module for ASK modulation in IF band and
frequency spreading with DSSS scheme. The modulated signal will be
further up-converted into 2.4-GHz ISM band for final transmission.
3.2.4 DC/DC Converter
The power supply for a handheld device should be able to keep the DC
voltage output at a constant level even though the input battery voltage
is continuously dropping down. There are two DC/DC converters; the
3.3-V supply is used for the baseband IC and RF module. The 5-V
supply is only used for the JB8, but it would be eliminated in the final
product when the low-voltage version JT8 is used.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..
