TH72031
868/915MHz
FSK Transmitter
Features
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Fully integrated PLL-stabilized VCO
Frequency range from 850 MHz to 930 MHz
Single-ended RF output
FSK through crystal pulling allows modulation
from DC to 40 kbit/s
High FSK deviation possible for wideband data
transmission
Wide power supply range from 1.95 V to 5.5 V
Very low standby current
On-chip low voltage detector
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High over-all frequency accuracy
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FSK deviation and center frequency independ-
ently adjustable
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Adjustable output power range from
-12 dBm to +9.5 dBm
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Adjustable current consumption from
5.1 mA to 13.4 mA
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Conforms to EN 300 220 and similar standards
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8-pin Small Outline Integrated Circuit (SOIC)
Ordering Information
Part Number
TH72031
Temperature Code
K (-40°C to 125°C)
Package Code
DC (SOIC8)
Delivery Form
98 pc/tube
2500 pc/T&R
Application Examples
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General digital data transmission
Tire Pressure Monitoring Systems (TPMS)
Remote Keyless Entry (RKE)
Wireless access control
Alarm and security systems
Garage door openers
Remote Controls
Home and building automation
Low-power telemetry systems
Pin Description
FSKDTA
1
FSKSW
2
ROI
3
ENTX
4
TH72031
8
VEE
7
OUT
6
VCC
5
PSEL
General Description
The TH72031 FSK transmitter IC is designed for applications in the European 868 MHz industrial-scientific-
medical (ISM) band, according to the EN 300 220 telecommunications standard. It can also be used for any
other system with carrier frequencies ranging from 850 MHz to 930 MHz (e.g. for applications in the US 902
to 928 MHz ISM band).
The transmitter's carrier frequency f
c
is determined by the frequency of the reference crystal f
ref
. The inte-
grated PLL synthesizer ensures that each RF value, ranging from 850 MHz to 930 MHz, can be achieved.
This is done by using a crystal with a reference frequency according to: f
ref
= f
c
/N, where N = 32 is the PLL
feedback divider ratio.
3901072031
Rev. 008
Page 1 of 20
Data Sheet
June/07
MELEXIS [ Melexis Microelectronic Systems ]
