TH7108 868/915MHz FSK/FM/ASK Transmitter Features ! Fully integrated, PLL-stabilized VCO ! Adjustable output power range from ! Frequency range from 850 MHz to 920 MHz -15 dBm to +1 dBm ! FSK through crystal pulling allows modulation ! Adjustable current consumption from from DC to 40 kbit/s 6.2 mA to 12.5 mA ! High FSK deviation possible for wideband data ! FSK deviation and center frequency independ- transmission ently adjustable ! ASK achieved by on/off keying of internal ! Differential output well-suited for loop antenna power amplifier ! External clock available for µC drive, ! FM possible with external varactor down to 1.9 V supply ! Wide power supply range from 2.2 V to 5.5 V ! ”Clock only” mode ! High over-all frequency accuracy ! Conforms to EN 300 220 and similar standards ! Very low standby current Ordering Information Part No. Temperature Code Package Code TH7108 E (-40 C° to 85 °C) FC (QSOP16) Application Examples Pin Description ! Keyless car and central locking 1 16 LF1 LF2 ! Low-power telemetry 2 SUB 15 VCC ! Alarm and security systems DATA 3 14 VEE ! General digital data transmission ! General analog audio signal transmission RO2 4 13 OUT1 TH7108 5 12 RO1 OUT2 ENTX 6 11 VEE ENCK 7 10 VCC 8 9 PS CKOUT General Description The TH7108 FSK/ASK/FM transmitter IC is designed for applications in the European 868MHz 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 920 MHz (e.g. for applications in the US 915MHz ISM band). The transmitter's carrier frequency f is determined by the frequency of the reference crystal f that is used. c ref 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: f = f /N, where N = 32 is the PLL feed- ref c back divider ratio. 3901007108 Page 1 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter Document Content 1 Theory of Operation...................................................................................................3 1.1 General............................................................................................................................... 3 1.2 Block Diagram .................................................................................................................... 3 2 Functional Description ..............................................................................................4 2.1 FSK Modulation..................................................................................................................4 2.2 Frequency Modulation ........................................................................................................ 4 2.3 ASK Modulation..................................................................................................................4 2.4 Mode Control Logic.............................................................................................................4 3 Pin Definition and Description..................................................................................5 4 Electrical Characteristics ..........................................................................................7 4.1 Absolute Maximum Ratings ................................................................................................ 7 4.2 Normal Operating Conditions.............................................................................................. 7 4.3 Crystal Parameters.............................................................................................................7 4.4 DC Characteristics..............................................................................................................8 4.5 AC Characteristics..............................................................................................................8 4.6 Output Power Selection...................................................................................................... 8 5 Test Circuit .................................................................................................................9 5.1 Test circuit component list (Fig. 2) ...................................................................................... 9 6 Spectrum Plots.........................................................................................................10 7 Package Information................................................................................................12 8 Reliability Information..............................................................................................13 9 ESD Precautions ......................................................................................................13 10 Disclaimer.................................................................................................................14 3901007108 Page 2 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 1 Theory of Operation 1.1 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 P can be adjusted in six steps from o P = –15 dBm to +1 dBm either by changing the value of resistor RPS or by varying the voltage V at pin o PS 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 kΩ. Bandgap biasing ensures stable operation of the IC at a power supply range of 2.2 V to 5.5 V. 1.2 Block Diagram RPS VCC 10 VCC 15 PS 9 VEE 14 OUT1 CKOUT div 8 13 antenna PA or div32 8 balun OUT2 VCC 12 VEE RO1 PFD 11 VCO 5 ENCK XTAL XOSC mode 7 RO2 control charge ENTX 4 CX2 pump 6 CX1 3 DATA 1 LF1 16 LF2 2 SUB CF1 CF2 RF1 Fig. 1: Block diagram with external components 3901007108 Page 3 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 2 Functional Description 2.1 FSK Modulation A Colpitts crystal oscillator (XOSC) is used as the reference oscillator of a phase-locked loop (PLL) synthe- sizer. FSK modulation is achieved by pulling the crystal (XTAL) through the data. So a CMOS-compatible data stream applied at input DATA digitally modulates the XOSC. Two external pulling capacitors CX1 and CX2 allow the FSK deviation and center frequency to be adjusted independently. At DATA = LOW CX2 is connected in parallel to CX1 leading to the low-frequency component of the FSK spectrum (f ); while at min DATA = HIGH CX2 is deactivated and the XOSC is set to its high frequency, leading to f . max An external reference signal can be directly AC-coupled to pin RO1. Then the TH7108 is used without an XTAL. The reference signal has to contain the FSK (or FM) and sets the carrier frequency. 2.2 Frequency Modulation For FM operation an external varactor is required. It simply acts as a pulling capacitor connected in series to the crystal. Then the analog modulation signal, applied through a series resistor, directly modulates the XOSC. 2.3 ASK Modulation The TH7108 can be ASK-modulated by applying data directly at pin PS. This turns the PA on and off and therefore leads to an ASK signal at the output. 2.4 Mode Control Logic The mode control logic allows four different modes of operation as listed in the following table. The mode control pins ENCK and ENTX are pulled-down internally. This guarantees that the whole circuit is shut down if these pins are left floating. The clock output CKOUT can be used to drive a µC. This output can be activated by the ENCK pin as re- quired for any specific application. Clock frequency is 1/8 of the reference crystal frequency. ENCK ENTX Mode Description 0 0 all OFF whole circuit in standby 0 1 TX only TX active, no clock available 1 0 clock only TX standby and clock available 1 1 all ON TX active and clock available 3901007108 Page 4 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 3 Pin Definition and Description Pin No. Name I/O Type Functional Schematic Description 1 LF1 output charge pump output, con- nection to loop filter LF1 200Ω 1 2 SUB ground negative power supply, sub- strate connection 3 DATA input FSK data input, CMOS-compatible DATA 1.8k 3 4 RO2 analog I/O XOSC FSK pulling pin, MOS switch RO2 4 5 RO1 analog I/O XOSC connection to XTAL, Colpitts type crystal oscilla- 37k RO1 tor 5 28p 28p 6 ENTX input mode control input, CMOS- compatible with internal pull- ENTX down 1.1k 6 7 ENCK input mode control input, CMOS- compatible with internal pull- ENCK 1.1k down 7 3901007108 Page 5 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter Pin No. Name I/O Type Functional Schematic Description 8 CKOUT output clock output, CMOS-compatible CKOUT 200Ω 8 9 PS analog I/O power-select and ASK input, high-impedance comparator 20µA logic PS 200Ω TX standby: I = 0 9 PS TX active: I = 20µA PS 10 VCC supply positive power supply 11 VEE ground negative power supply 12 OUT2 output VCC VCC differential power amplifier output, open collector OUT2 OUT1 13 12 13 OUT1 output differential power amplifier output, open collector VEE VEE VEE 14 VEE ground negative power supply 15 VCC supply positive power supply 16 LF2 input VCO tuning input, connec- tion from loop filter LF2 200Ω 16 5p 3901007108 Page 6 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 4 Electrical Characteristics 4.1 Absolute Maximum Ratings Parameter Symbol Condition Min Max Unit Supply voltage V 0 7.0 V CC Input voltage V -0.3 V+0.3 V IN CC Storage temperature T -65 150 °C STG Junction temperature T 150 °C J Thermal Resistance R 112 K/W thJA Power dissipation P 0.12 W diss V human body model, 1) -1.0 +1.0 ESD1 Electrostatic discharge kV V human body model, 2) -0.75 +0.75 ESD2 1) all pins except OUT1, OUT2 2) pins OUT1, OUT2 4.2 Normal Operating Conditions Parameter Symbol Condition Min Max Unit Supply voltage V 2.2 5.5 V CC Operating temperature T -40 85 °C A Input low voltage CMOS V ENTX, ENCK, DATA pins 0.3*V V IL CC Input high voltage CMOS V ENTX, ENCK, DATA pins 0.7*V V IH CC XOSC frequency f set by the crystal 26.5 28.75 MHz ref 890 VCO frequency f 850 MHz f = 32 • f c c ref T < 70°C, 920 A V ≥ 2.5V CC Clock frequency f f = f / 8 3.3 3.6 MHz clk c ref FSK deviation depends on CX1, CX2 and kHz Δf ±5 ±100 FSK crystal parameter Data rate FSK R NRZ 40 kbit/s FSK FM deviation Δf adjustable with V1 and CX3 ±6 kHz FM Modulation frequency FM f 5 kHz mod Data rate ASK R NRZ 40 kbit/s ASK 4.3 Crystal Parameters Parameter Symbol Condition Min Max Unit Crystal frequency f fundamental mode, AT 26.5 28.75 MHz 0 Load capacitance C 10 15 pF L Static capacitance C 7 pF 0 Resonance resistance R 40 Ω 1 Spurious response a only required for FSK -10 dB spur 3901007108 Page 7 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 4.4 DC Characteristics all parameters under normal operating conditions, unless otherwise stated; typical values at T = 23 °C and V = 3 V A CC Parameter Symbol Condition Min Typ Max Unit Standby current I ENCK=0, ENTX=0 0.05 0.1 µA SBY Clock only current I ENCK=1, ENTX=0 0.7 0.9 1.6 mA CLK Operating current I ENCK=x, ENTX=1, 7 9.5 14 mA CC RPS=56kΩ Input current I DATA=x, ENCK=0, -1 1 µA IN ENTX=0 Pull down current I ENCK=1, ENTX=1 3 8 30 µA PD Pull up current I ENCK=1, ENTX=1 14 20 24 µA PS MOS switch On resistance R DATA=0, ENTX=1 10 25 80 ON Ω 4.5 AC Characteristics all parameters under normal operating conditions, unless otherwise stated; typical values at T = 23 °C and V = 3 V; A CC ENCK = 1, ENTX = 1, RPS = 56 kΩ, f = 868.3 MHz, test circuit shown in Fig. 2 c Parameter Symbol Condition Min Typ Max Unit Output power P -2 dBm o Reference spurs P -44 dBm @ f ± f ref c ref Clock spurs P -44 dBm @ f ± f clk c clk Harmonic content P @ 2f , 3f , 4f -40 dBm harm c c c Spurious output signal P -60 dBm V ≤ 0.1V off PS Phase noise PN -82 -78 dBc/Hz @ f ± 200kHz c VCO gain K 300 MHz/V VCO Charge pump current I ±260 µA CP Clock voltage swing V C = 5pF 2 V CKOUT load pp Start-up time t from ”all OFF” to any 1.0 1.2 ms on other mode 4.6 Output Power Selection typical values at T = 23 °C and V = 3 V: A CC ENCK = 1, ENTX = 1, f = 868.3 MHz, test circuit shown in Fig. 2 c 56 47 39 27 15 RPS / kΩ Ω Ω Ω ≥ ≥ ≥ ≥ 68 V / V 1.1 0.9 0.7 0.5 0.3 ≥ ≥ ≥ ≥ 2 PS I / mA 12.5 9.5 8.5 7.8 7.0 6.2 cc P / dBm 1 -2 -5 -8 -10 -15 o P / dBm ≤-40 ≤-40 ≤-40 ≤-45 ≤-45 ≤-50 harm 3901007108 Page 8 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 5 Test Circuit OUT L3 C4 C1 C6 C5 C3 C2 L1 L2 RPS Fig. 2: Test circuit for FSK, ASK and FM; with 50Ω matching network RF2 CX2 XTAL RF1 R3 CX3 CX1 CF2 CF1 V1 R1 R2 C7 1 12 2 1 2 12 12 3 1 2 5.1 Test circuit component list (Fig. 2) Part Size Value Tolerance Description CF1 0603 5.6 nF ±10% loop filter capacitor CF2 0603 27 pF ±10% loop filter capacitor CX1 0603 56 pF _FSK ±5% XOSC capacitor for FSK (Δf = ±30 kHz), note 1 CX1 0603 18 pF XOSC capacitor for ASK, trimmed to f note 1 _ASK ±5% C, CX2 0603 1 nF XOSC capacitor (for FSK only), note 1 ±5% CX3 0603 1 nF ±10% XOSC capacitor (for FM only) C1 0603 0.47 pF impedance matching capacitor ±5% C2 0805 1.0 pF impedance matching capacitor ±5% C3 0805 1.8 pF impedance matching capacitor ±5% C4 0603 150 pF ±5% impedance matching capacitor C5 0603 330 pF ±10% blocking capacitor C6 0603 330 pF blocking capacitor ±10% C7 1206 220 nF blocking capacitor ±20% L1 0603 10 nH impedance matching inductor ±5% L2 0603 15 nH ±5% impedance matching inductor L3 0805 15 nH impedance matching inductor ±5% RF1 0805 loop filter resistor 1.6 kΩ ±10% RF2 0805 loop filter resistor 2.0 kΩ ±10% RPS 0805 56 kΩ ±10% power-select resistor R1 0805 470 kΩ ±10% optional pull-up resistor R2 0805 varactor bias resistor, (for FM only) 30 kΩ ±10% R3 0805 ASK jumper, (for ASK only) 0 Ω ±10% V1 SOD323 BB535 varactor diode (for FM only) XTAL HC49/S 27.1344 MHz crystal, C = 12 pF to 15 pF, C = 7 pF, ±30ppm calibr. load 0, max fundamental wave R = 40 Ω ±30ppm temp. m, max Note 1: value depends on crystal parameters 3901007108 Page 9 of 14 Data Sheet Rev. 008 May/03 1 16 LF1 LF2 2 15 VCC SUB VCC GND 3 14 FSK DATA VEE GND 4 13 RO2 FM/ASK OUT1 GND 12 5 RO1 OUT2 ENTX 6 11 GND ENTX VEE VCC 7 10 ENCK ENCK VCC GND 8 9 CKOUT CKOUT PS GND TH7108 868/915MHz FSK/FM/ASK Transmitter 6 Spectrum Plots All plots depict TH7108‘s typical performance at V = 3.0 V and T = 23 °C, CC A derived with the test circuit shown in Fig. 2. Fig. 3: RF output signal and spurious emissions, CW mode (DATA = HIGH) Fig. 4: Single-sideband phase noise at 500 kHz offset, CW mode (DATA = HIGH) 3901007108 Page 10 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter Fig.5: FSK modulation with R = 6.6 kbit/s NRZ FSK Fig. 6: ASK modulation with R = 4 kbit/s NRZ ASK Fig. 7: FM with f = 2 kHz, FM input signal with 1 V around 1.5 V , DATA = HIGH mod pp DC 3901007108 Page 11 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 7 Package Information D ZD e 7° 16 1 0.254 L (0.010) DETAIL-A b + 3° 7° DETAIL-A 0.36 x 45° BSC (0.0014x45°) C .10 (.004) Fig. 8: QSOP16 (Quarter size Small Outline Package) all Dimension in mm, coplanarity < 0.1mm D E1 E A A1 A2 e b ZD C L α α α α min 4.80 3.81 5.79 1.35 0.10 1.37 0.20 0.19 0.40 0° 0.635 0.230 max 4.98 3.99 6.20 1.75 0.25 1.50 0.30 0.25 1.27 8° all Dimension in inch, coplanarity < 0.004” min 0.189 0.150 0.228 0.0532 0.0040 0.054 0.008 0.075 0.016 0° 0.025 0.009 max 0.196 0.157 0.244 0.0688 0.0098 0.059 0.012 0.098 0.050 8° 3901007108 Page 12 of 14 Data Sheet Rev. 008 May/03 A A2 E1 A1 E TH7108 868/915MHz FSK/FM/ASK Transmitter 8 Reliability Information Melexis devices are classified and qualified regarding suitability for infrared, vapor phase and wave soldering with usual (63/37 SnPb-) solder (melting point at 183degC). The following test methods are applied: • IPC/JEDEC J-STD-020A (issue April 1999) Moisture/Reflow Sensitivity Classification For Nonhermetic Solid State Surface Mount Devices • CECC00802 (issue 1994) Standard Method For The Specification of Surface Mounting Components (SMDs) of Assessed Quality • MIL 883 Method 2003 / JEDEC-STD-22 Test Method B102 Solderability For all soldering technologies deviating from above mentioned standard conditions (regarding peak temperature, temperature gradient, temperature profile etc) additional classification and qualification tests have to be agreed upon with Melexis. The application of Wave Soldering for SMD’s is allowed only after consulting Melexis regarding assurance of adhesive strength between device and board. For more information on manufacturability/solderability see quality page at our website: http://www.melexis.com/ 9 ESD Precautions Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. Your Notes 3901007108 Page 13 of 14 Data Sheet Rev. 008 May/03 TH7108 868/915MHz FSK/FM/ASK Transmitter 10 Disclaimer Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Melexis for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life- support or life-sustaining equipment are specifically not recommended without additional processing by Melexis for each application. The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering of technical or other services. © 2002 Melexis NV. All rights reserved. For the latest version of this document. Go to our website at www.melexis.com Or for additional information contact Melexis Direct: Europe and Japan: All other locations: Phone: +32 1367 0495 Phone: +1 603 223 2362 E-mail: sales_europe@melexis.com E-mail: sales_usa@melexis.com QS9000, VDA6.1 and ISO14001 Certified 3901007108 Page 14 of 14 Data Sheet Rev. 008 May/03