th7122 Melexis Company, th7122 Datasheet - Page 16

• Manufacturer Part Number: th7122
• Description: Transceiver - 27 To 930mhz, Fsk/fm/ask, Multi-channel Lqfp32
• Manufacturer: Melexis Company

3.3.2
The maximum output power is adjustable via
the external resistor RPS as shown in Figure
8. There are four predefined power settings
in programmable user mode which can be
set in the register TXPOWER. The maxi-
mum power setting P4 is the default setting.
3.3.3
The RF carrier generated by the PLL frequency synthesizer can be ASK or FSK modulated. Depending on
the selected user mode, the modulation type can be selected either by the ASK/FSK pin or via the serial
control interface. Data is applied to pin IN_DTA. The data signal can be inverted by the bit DTAPOL. The
following tables for ASK and FSK modulation are valid for non-inverted data (DTAPOL = 0)
3.3.4
39010 07122
Rev. 008
IN_DTA
0
1
Output Power Adjustment
Modulation Schemes
ASK Modulation
Fig. 8:
(according to the selected output power)
Output power vs. RPS
Power amplifier is turned off
Power amplifier is turned on
Description
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-10.00
-20.00
-40.00
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The transceiver is ASK-modulated by
turning on and off the power amplifier.
Please also refer to para. 1.3 for ASK
modulation limits.
FSK/FM/ASK Transceiver
RPS / kOhm
P4
10
27 to 930MHz
TH7122
315MHz
433MHz
868MHz
915MHz
Data Sheet
June/07
100