User's Manual

SK-7265 RF WIRELESS KEYBOARD Page No: 3 of
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3. Electrical Specification
Functional Block diagram:
Microprocessor EMC78P451
3.1 Keyboard Transmitter
Operating voltage
The operating voltage range for keyboard is 2.2 ~ 3.3 Vdc.
There are 2 AA batteries providing 3.0V for operation
Current consumption
Typical current consumption is 8 mA, .Maximum at 10 mA
Suspend current is under 50 uA.
Power consumption
The power consumption is less than 0.024 W at operation mode and 150 uW
at sleep mode.
Low Power Indicator
Low power indicator on the keyboard will be lit during hitting key when the
battery voltage applying to keyboard is less than about 2.5V.
CPU
Crystal : 4.9152MH
RF Link
PC Host
PS2 Interface
cable
Low power indicator
N
um
L
,CAP, Scrol LED
Data indicator
Keyboard
(Base-Band)
CPU: EMC78P257
&CYC63743
Crystal : 8MHZ
USB clock :6MHZ internal
TX-Freq :
27.095MHz
27.145 MHz
RX-Freq :
Crystal : 26.690
/
2
6.
6
4
0
MHz
Base-Band
Microprocessor
MA6135