ADNK-5033-FS27 Avago Technologies US Inc., ADNK-5033-FS27 Datasheet - Page 4

• Manufacturer Part Number: ADNK-5033-FS27
• Description: KIT REF DES OPT MOUSE ADNS-5030
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNK-5033-FS27

• Main Purpose: Reference Design, Optical Mouse
• Utilized Ic / Part: ADNS-5030
• Wireless Frequency: 27 MHz
• Interface Type: USB
• Modulation: FSK
• For Use With/related Products: MC68HC908QY4A, MC68HC908JB12
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Figure 3. MC68HC908QY4A-ADNS-5030 Optical Mouse Hardware Block Diagram - Mouse
4
RF Receiver
The RF receiver is implemented by using a single-chip
solution (3361 compatible part) that includes:
• A frequency downward conversion mixer
• A local oscillator circuit
• A baseband FSK quadrature demodulation unit
The RF input signal from the antenna, is frequency
down converted into an IF signal at 455kHz by the
mixer and oscillator circuits. The IF frequency value is
equal to the RF input frequency plus or minus the LO
input frequency. The higher frequency components
should be filtered out by using a passive IF filter. The
bandwidth should be increased from 15 kHz to 20 kHz
to match the data rate change on the transmitter side.
However, the image frequency component would not
be filtered out by the IF filter. This should be considered
in the PCB layout in order to prevent any noise
component at image frequency to be injected into the
mixer input. An example of this would be a noise
pattern generated from the MCU.
ANTENNA
LOOP
Amp
I
Z
Z-axis Encoder
Oscillator
(Discrete)
Crystal
750
13.5225M
Hz
Buttons
IR Rx
DGN
LD
RF_DATA
RF_OFF
C
R
L
I
PTB0
PTB1
PTB3
MC68HC908QY4
PTA5
PTA4
PTA2
PTA0
PTA1/TCH1
PTB2
PTB7
PTB6
PTB5
PTB4
PTA3
Hardware Implementation
The standard hardware to implement a wireless optical
mouse is shown in Figure 3. For X and Y movement,
the optical encoder is used. The Z-wheel movement is
detected by a set of optical sensors that output
quadrature signals. For each button there is a switch
that is pulled up internally by the built in pull up
resistors.
The functions of the MC68HC908QY4A are to:
• Get the XY displacement from the optical sensor
• Detect the Z displacement
• Check button status
• Control the RF circuitry to send out data
• Perform the overall power management
Three standard left, middle and right buttons together
with one buttons together with one button for the
identity device (ID) code are implemented. The ID code
can be stored in the FLASH of the MC68HC908QY4A.
When the ID button in the transmitter and the one in
the receiver are pressed, a random ID code is generated
at the transmitter and sent to the receiver. After
receiving the new ID code, the receiver stores it in the
FLASH of the receiver MCU.
ADNS-5030
SCLK
MOSI
MISO
NCS
NRESET
ADNS-5030
SENSOR
XY_LED
IMAGE
GND
VDD
100nF
4u7F