TH71072 315/433MHz ASK Transmitter / LO Source Features ! Fully integrated, PLL-stabilized VCO ! Flexible frequency range from 310 MHz to 450 MHz ! ASK achieved by on/off keying of internal power amplifier ! FM possible with external varactor ! Wide power supply range from 2.2 V to 5.5 V ! High over-all frequency accuracy ! Very low standby current ! ! ! ! ! Adjustable output power range from -15 dBm to -1 dBm Adjustable current consumption from 4.8 mA to 11.5 mA Single-ended RF output Clock output for µC drive Conforms to EN 300 220 and similar standard Ordering Information Part No. Temperature Range Package TH71072 -40 C° to 85 °C SOIC8 Application Examples ! ! ! ! ! ! Pin Description Keyless car and central locking Low-power telemetry Alarm and security systems General digital data transmission General analog audio signal transmission Local oscillator signal generation 3901071072 Rev. 004 8 VEE LF 1 RO 2 ENTX 3 CKOUT 4 Page 1 of 10 TH71072 7 OUT 6 VCC 5 PS/DATA Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source General Description The TH71072 ASK transmitter IC is designed for applications in the European 433MHz 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 310 MHz to 450 MHz (e.g. for applications in the US 315MHz 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 310 MHz to 450 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. Theory of Operation General As depicted in Fig.1, the TH71072 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 behaviour 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 = –15 dBm to -1 dBm, either by changing the value of resistor R1 or by varying the voltage VPS at pin PS/DATA. The open-collector output (OUT) can be used to either drive a loop antenna or to feed a single-ended load impedance. This could be, for example λ /4 monopol antenna or a 50Ω output port. In any case, an impedance matching network should be added in order to achieve maximum available RF power. Bandgap biasing ensures stable operation of the IC at a power supply range of 2.2 V to 5.5 V. Clock Output The TH71072 feature a clock output (CKOUT) that can be used to drive a µC. The frequency at CKOUT is fref/4. The clock output is slew-rate limited in order to keep spurious signal emission as low as possible. The voltage swing at CKOUT depends on the capacitive loading at this pin. It is approximate 2 Vpp at Cload = 5 pF 3901071072 Rev. 004 ASK Modulation The TH71072 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. LO Source Many applications require a stable RF source. For this purpose, the TH71072 can be used without modulation as an easy-to-use, PLL-stabilized, continuous wave (CW) generator. Frequency Modulation (FM) 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. 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. ENTX 0 1 Mode Description TX disabled whole circuit in standby TX enable TX active Table 1: Modes of operation Page 2 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source 8 VEE mode control VCO PA CF2 RF1 CF1 LF 1 PFD XTAL CX1 2 RO XOSC div 4 CKOUT 4 div32 charge pump VCC 6 PS/DATA 5 VCC OUT 7 ENTX 3 Block Diagram Fig. 1: TH71072 block diagram with external components 3901071072 Rev. 004 Page 3 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source Pin Definition and Description Pin No. 1 Name LF I/O Type Functional Schematic Description analog I/O connection to loop filter, charge pump output, VCO tuning input 200Ω LF 1 200Ω 5p 2 RO analog I/O XOSC connection to XTAL, Colpitts type crystal oscillator 37k RO1 28p 2 28p 3 ENTX input ENTX mode control input, CMOScompatible with internal pulldown 1.1k 3 4 CKOUT output clock output, CMOS-compatible CKOUT 200Ω 4 5 PS/DATA analog I/O 20µA PS/DATA 200Ω power-select and ASK input, high-impedance comparator logic 5 6 7 VCC OUT supply positive power supply VCC output VCC Power amplifier output, open collector OUT 7 VEE VEE 8 VEE 3901071072 Rev. 004 ground negative power supply Page 4 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source Technical Data Absolute Maximum Ratings Parameter Symbol Condition Min Max Unit -0.3 7.0 V Supply voltage Vcc Input voltage Vin ENTX pin -0.3 VCC+0.3 V Input current Iin ENTX pin -1.0 1.0 mA -40 150 °C -1.0 +1.0 kV Min Max Unit Storage temperature TSTG Electrostatic discharge VESD human body model, MIL STD 833D method 3015.7 Normal Operating Conditions Parameter Symbol Condition Supply voltage Vcc 2.2 5.5 V Operating temperature Ta -40 85 °C XOSC frequency fref set by the crystal 9.69 14 MHz VCO frequency fc fc = 32 • fref 310 450 MHz Clock frequency fclk fclk = fref / 4 2.42 3.50 MHz DC Characteristics all parameters under normal operating conditions, unless otherwise stated; typical values at Ta = 23 °C and Vcc = 3 V Parameter Standby current Operating current Symbol ISBY Icc Condition Min ENTX=0 ENTX=1, VPS=1.1V 7 Typ Max Unit 0.05 0.1 µA 9 10 mA Input HIGH voltage VHIGH ENTX pin 0.7*Vcc Vcc+0.3 V Input LOW voltage VLOW ENTX pin -0.3 0.3*Vcc V Input current Iin ENTX=0 -1 1 µA Pull down current Ipd ENTX=1 2 15 µA 3901071072 Rev. 004 Page 5 of 10 8 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source AC Characteristics all parameters under normal operating conditions, unless otherwise stated; typical values at Ta = 23 °C and Vcc = 3 V; ENTX = 1, VPS = 1.1V, fc = 433.6 MHz, test circuit shown in Fig. 2 Parameter Symbol Output power Po FM deviation ∆fFM Modulation frequency FM Data rate ASK Condition Min Typ Max Unit -4 dBm ±6 kHz fmod 5 kHz RASK 40 kbit/s @ fc ± fref -44 dBm @ 2fc , 3fc , 4fc -40 dBm Reference spurs Pref Harmonic content Pharm adjustable with varactor and VFM Spurious output signal Poff VPS ≤ 0.1V -60 dBm Phase noise PN @ fc ± 500kHz -87 dBc/Hz KVCO 200 MHz/V ICP ±260 µA 2 Vpp VCO gain Charge pump current Clock voltage swing VCKOUT Start-up time Cload = 5pF ton 0.9 from ”all OFF” to any other mode ms Output Power Selection typical values at Ta = 23 °C and Vcc = 3 V: ENTX = 1, fc = 433.6 MHz, test circuit shown in Fig. 2 R1 / kΩ Ω 0 R2 / kΩ Ω 7.5 11 15 24 43 4.7 4.7 4.7 4.7 4.7 VPS / V ≥2 1.1 0.9 0.7 0.5 0.3 Icc / mA 11.5 8.6 7.3 6.2 5.3 4.8 Po / dBm 2 -1 -4 -7 -10 -12 Pharm / dBm ≤-40 ≤-40 ≤-40 ≤-45 ≤-45 ≤-50 If the transmitter is operated at any supply voltage Vcc, the values for R1 and R2 can be calculated as allows: V R1 = R2 • cc − 1 VPS Crystal Parameter Parameter Symbol Condition Min Max Unit Crystal frequency fcrystal fundamental mode, AT 9.69 14 MHz Load capacitance Cload 10 15 pF Static capacitance C0 7 pF Resonance resistance Rm 60 Ω Spurious response aspur -10 dB 3901071072 Rev. 004 Page 6 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source C1 L1 C3 PS 5 DATA L2 6 Test Circuit OUT Fig. 2: Test circuit for ASK with 50Ω matching network VCC 7 OUT VEE 8 C2 CKOUT R1 4 ENTX 3 2 1 LF RO R2 CX C4 CF1 1 2 DATA GND 1 2 VCC ENTX GND 1 2 3 CKOUT GND CF2 XTAL 1 2 VCC GND RF1 Test circuit component list to Fig. 2 Part Size Value Tolerance CF1 0603 10 nF ±10% loop filter capacitor CF2 0603 150 pF ±10% loop filter capacitor CX 0603 120 pF ±10% XOSC capacitor C1 0603 1 nF ±5% impedance matching capacitor C2 0603 3.3 pF ±5% impedance matching capacitor C3 0603 330 pF ±10% blocking capacitor C4 0805 33 nF ±10% blocking capacitor L1 0603 270 nH ±5% impedance matching inductor L2 0603 56 nH ±5% impedance matching inductor RF1 0603 ±10% foop filter resistor R1 0603 ±10% ASK power-select resistor, not requirement at CW mode R2 0603 ±10% ASK or CW mode power-select resistor XTAL HC49/S 470 Ω See output power selection table See output power selection table 13.55 MHz fundamental wave 3901071072 Rev. 004 ±30ppm calibration ±30ppm temp. Description crystal, Cload = 12 pF to 15 pF, C0, max = 7 pF, Rm, max = 60 Ω Page 7 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source Spectrum Plots All plots depict TH71072‘s typical performance at Vcc = 3.0 V and Ta = 23 °C, derived with the test circuit shown in Fig. 2. Fig. 3: Output spectrum with unmodulated carrier and harmonics Fig. 4: Output spectrum with unmodulated carrier, clock spurs and PLL reference spurs Fig. 5: Output spectrum with ASK modulation at 20 kbit/s NRZ 3901071072 Rev. 004 Page 8 of 10 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source Package Information E1 E 1 2 3 D α A1 A L b e Fig. 6: SOIC8 (Small Outline Package) all Dimension in mm, coplanarity < 0.1mm D E1 E A A1 e b L α min 4.80 3.81 5.80 1.32 0.10 1.27 0.36 0.41 0° max 4.98 3.99 6.20 1.72 0.25 0.46 1.27 8° all Dimension in inch, coplanarity < 0.004” 3901071072 Rev. 004 min 0.189 0.150 0.2284 0.060 0.0040 0.05 0.014 0.016 0° max 0.196 0.157 0.2440 0.068 0.0098 0.050 8° Page 9 of 10 0.018 Data Sheet Dec. 2001 TH71072 315/433MHz ASK Transmitter / LO Source Your Notes Important Notice 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 lifesustaining 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. © 2000 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 1361 1631 E-mail: [email protected] Phone: +1 603 223 2362 E-mail: [email protected] QS9000, VDA6.1 and ISO14001 Certified 3901071072 Rev. 004 Page 10 of 10 Data Sheet Dec. 2001