TH7108EFC

TH7108EFC Datasheet

TH7108

Part	Datasheet
TH7108EFC	TH7108EFC (pdf)

PDF Datasheet Preview
TH7108 868/915MHz FSK/FM/ASK Transmitter ! Fully integrated, PLL-stabilized VCO ! Frequency range from 850 MHz to 920 MHz ! FSK through crystal pulling allows modulation from DC to 40 kbit/s ! High FSK deviation possible for wideband data transmission ! ASK achieved by on/off keying of internal power amplifier ! FM possible with external varactor ! Wide power supply range from V to V ! High over-all frequency accuracy ! Very low standby current ! Adjustable output power range from -15 dBm to +1 dBm ! Adjustable current consumption from mA to mA ! FSK deviation and center frequency independ- ently adjustable ! Differential output well-suited for loop antenna ! External clock available for µC drive, down to V supply ! ”Clock only” mode ! Conforms to EN 300 220 and similar standards Ordering Information Part No. TH7108 Temperature Code E -40 C° to 85 °C Package Code FC QSOP16 Application Examples ! Keyless car and central locking ! Low-power telemetry ! Alarm and security systems ! General digital data transmission ! General analog audio signal transmission Pin Description LF1 1 SUB 2 DATA 3 RO2 4 RO1 5 ENTX 6 ENCK 7 CKOUT 8 TH7108 16 LF2 15 VCC 14 VEE 13 OUT1 12 OUT2 11 VEE 10 VCC 9 PS The TH7108 FSK/ASK/FM transmitter IC is designed for applications in the European 868MHz industrialscientific-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 920 MHz e.g. for applications in the US 915MHz ISM band . The transmitter's carrier frequency fc is determined by the frequency of the reference crystal fref that is used. The integrated PLL synthesizer ensures that each RF value, ranging from 850 MHz to 920 MHz, can be achieved by using a crystal with reference frequency according to fref = fc/N, where N = 32 is the PLL feedback divider ratio. Page 1 of 14 Data Sheet May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter Document Content 1 Theory of Operation 3 Block Diagram 3 2 Functional Description FSK Modulation 4 Frequency Modulation 4 ASK 4 Mode Control 4 3 Pin Definition and Description 4 Electrical Characteristics Absolute Maximum Ratings 7 Normal Operating 7 Crystal 7 DC 8 AC 8 Output Power Selection 8 5 Test Circuit Test circuit component list Fig. 2 9 6 Spectrum 7 Package Information 8 Reliability 9 ESD Precautions 10 Disclaimer Page 2 of 14 Data Sheet May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 1 Theory of Operation General As depicted in Fig.1, the TH7108 transmitter consists of a fully integrated voltage-controlled oscillator VCO , a divide-by-32 divider div32 , a phase-frequency detector PFD and a charge pump. An external loop filter at pin LF determines the dynamic behavior of the PLL and suppresses reference spurious signals. The VCO’s output signal feeds the power amplifier PA . RF signal power Po can be adjusted in six steps from Po = dBm to +1 dBm either by changing the value of resistor RPS or by varying the voltage VPS at pin PS. The open-collector differential output OUT1, OUT2 can be used to either directly drive a loop antenna or to be converted to a single-ended impedance by means of a balanced-to-unbalanced balun transformer. For maximum available output power, the differential output should be matched to a load of about 1 Bandgap biasing ensures stable operation of the IC at a power supply range of V to V. Block Diagram VCC 10 CKOUT 8 div 8 5 XTAL RO2 CX2 4 CX1 XOSC 3 DATA VCC 15 div32 PFD charge pump RPS PS 9 VCO mode control VEE 14 OUT1 13 OUT2 12

PDF Datasheet Preview

TH7108
868/915MHz FSK/FM/ASK Transmitter
! Fully integrated, PLL-stabilized VCO ! Frequency range from 850 MHz to 920 MHz ! FSK through crystal pulling allows modulation
from DC to 40 kbit/s ! High FSK deviation possible for wideband data
transmission ! ASK achieved by on/off keying of internal
power amplifier ! FM possible with external varactor ! Wide power supply range from V to V ! High over-all frequency accuracy ! Very low standby current
! Adjustable output power range from
-15 dBm to +1 dBm ! Adjustable current consumption from
mA to mA ! FSK deviation and center frequency independ-
ently adjustable ! Differential output well-suited for loop antenna ! External clock available for µC drive,
down to V supply ! ”Clock only” mode ! Conforms to EN 300 220 and similar standards
Ordering Information

Part No. TH7108

Temperature Code E -40 C° to 85 °C

Package Code FC QSOP16

Application Examples
! Keyless car and central locking ! Low-power telemetry ! Alarm and security systems ! General digital data transmission ! General analog audio signal transmission

Pin Description

LF1 1 SUB 2 DATA 3 RO2 4 RO1 5 ENTX 6 ENCK 7 CKOUT 8

TH7108
16 LF2 15 VCC 14 VEE 13 OUT1 12 OUT2 11 VEE 10 VCC 9 PS

The TH7108 FSK/ASK/FM transmitter IC is designed for applications in the European 868MHz industrialscientific-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 920 MHz e.g. for applications in the US 915MHz ISM band . The transmitter's carrier frequency fc is determined by the frequency of the reference crystal fref that is used. The integrated PLL synthesizer ensures that each RF value, ranging from 850 MHz to 920 MHz, can be achieved by using a crystal with reference frequency according to fref = fc/N, where N = 32 is the PLL feedback divider ratio.

Page 1 of 14

Data Sheet May/03

TH7108
868/915MHz FSK/FM/ASK Transmitter

Document Content
1 Theory of Operation 3 Block Diagram 3
2 Functional Description FSK Modulation 4 Frequency Modulation 4 ASK 4 Mode Control 4
3 Pin Definition and Description 4 Electrical Characteristics

Absolute Maximum Ratings 7 Normal Operating 7 Crystal 7 DC 8 AC 8 Output Power Selection 8 5 Test Circuit Test circuit component list Fig. 2 9 6 Spectrum 7 Package Information 8 Reliability 9 ESD Precautions 10 Disclaimer

Page 2 of 14

Data Sheet May/03

TH7108
868/915MHz FSK/FM/ASK Transmitter
1 Theory of Operation

General

As depicted in Fig.1, the TH7108 transmitter consists of a fully integrated voltage-controlled oscillator VCO , a divide-by-32 divider div32 , a phase-frequency detector PFD and a charge pump. An external loop filter at pin LF determines the dynamic behavior of the PLL and suppresses reference spurious signals. The VCO’s output signal feeds the power amplifier PA . RF signal power Po can be adjusted in six steps from Po = dBm to +1 dBm either by changing the value of resistor RPS or by varying the voltage VPS at pin PS. The open-collector differential output OUT1, OUT2 can be used to either directly drive a loop antenna or to be converted to a single-ended impedance by means of a balanced-to-unbalanced balun transformer. For maximum available output power, the differential output should be matched to a load of about 1 Bandgap biasing ensures stable operation of the IC at a power supply range of V to V.

Block Diagram

VCC 10

CKOUT 8
div 8
5 XTAL

RO2 CX2 4 CX1

XOSC 3 DATA

VCC 15
div32 PFD
charge pump

RPS PS 9

VCO mode control

VEE 14 OUT1 13

OUT2 12

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Datasheet ID: TH7108EFC 647810