EVB72005 Melexis Company, EVB72005 Datasheet - Page 6

• Manufacturer Part Number: EVB72005
• Description: 315mhz Fsk/ask Transmitter Evaluation Board Description
• Manufacturer: Melexis Company

2.8 Mode Control Logic
The mode control logic allows two different
modes of operation as listed in the following
table. The mode control pin ENTX is pulled-
down internally. This guarantees that the whole
circuit is shut down if this pin is left floating.
2.9 Timing Diagrams
After enabling the transmitter by the ENTX signal, the power amplifier remains inactive for the time t
transmitter start-up time. The crystal oscillator starts oscillation and the PLL locks to the desired output fre-
quency within the time duration t
and then the RF carrier can be FSK or ASK modulated.
39012 72005 01
Rev. 007
RF carrier
For more detailed information, please refer to the latest TH72005 data sheet revision.
FSKDTA
LOCK
ENTX
high
high
high
low
low
low
t
on
Fig. 5:
on
. After successful PLL lock, the LOCK signal turns on the power amplifier,
Timing diagrams for FSK and ASK modulation
Page 6 of 14
t
ASKDTA
ENTX
LOCK
ENTX
0
1
high
high
high
low
low
low
315MHz FSK/ASK Transmitter
Evaluation Board Description
TX standby
TX active
t
on
Mode
EVB72005
Description
EVB Description
TX disabled
TX enable
June/07
on
, the
t