EVB /433MHz Receiver Evaluation Board Description

Transcription

1 EVB702 35/433 Receiver Features Double-conversion superhet architecture for high degree of image rejection FSK demodulation with phase-coincidence demodulator Low current consumption in active mode and very low standby current Switchable LNA gain for improved dynamic range allows signal strength indication and ASK detection Ordering Information Part No. EVB FSK-C EVB ASK-C EVB FSK-C EVB ASK-C * EVB702-XXX-YYY-C with XXX = Reception frequency (35 or ) and YYY = Modulation (FSK or ASK). ** The evaluation board is supplied with a SMA connector. Application Examples Evaluation Board 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 General Description The TH702 FSK/ASK double-conversion superheterodyne receiver IC is designed for applications in the European 433 industrial-scientific-medical (ISM) band, according to the EN telecommunications standard. It can also be used for any other system with carrier frequencies ranging from 260 to 50 (e.g. for applications to FCC part 5 and ARIB STD-T67) Page of 4 EVB Description Rev. 02

2 EVB702 35/433 Receiver Document Content Theory of Operation...3. General EVB Technical Data Overview Block Diagram Mode Configurations LNA GAIN Control Frequency Planning Selected Frequency Plans Maximum Frequency Coverage Application Circuits FSK Application Circuit Circuit Diagram for FSK Reception Board Component Values for FSK Component Arrangement Top Side for FSK Reception ASK Application Circuit Circuit Diagram for ASK Reception Board Component Values for ASK Component Arrangement Top Side for ASK Reception... 3 Evaluation Board Layouts Package Description Soldering Information Disclaimer Page 2 of 4 EVB Description Rev. 02

3 EVB702 35/433 Receiver Theory of Operation. General With the TH702 receiver chip, various circuit configurations can be arranged in order to meet a number of different customer requirements. For FSK reception the IF tank used in the phase coincidence demodulator can be constituted by an external ceramic discriminator. In ASK configuration, the signal is fed to an ASK detector, which is constituted by the operational amplifier. The superheterodyne configuration is double conversion where MIX and MIX2 are driven by the internal local oscillator signals LO and LO2, respectively. This allows a high degree of image rejection, achieved in conjunction with an RF front-end filter. Efficient RF front-end filtering is realized by using a SAW, ceramic or helix filter in front of the LNA and by adding an LC filter at the LNA output. A single-conversion variant, called TH70, is also available. Both Receiver ICs have the same die. At the TH70 the second mixer MIX2 operates as an amplifier. The TH702 receiver IC consists of the following building blocks: PLL synthesizer (PLL SYNTH) for generation of the first and second local oscillator signals LO and LO2, parts of the PLL SYNTH are: the high-frequency VCO, the feedback dividers DIV_8 and DIV_2, a phase-frequency detector (PFD) with charge pump (CP) and a crystal-based reference oscillator () Low-noise amplifier (LNA) for high-sensitivity RF signal reception First mixer (MIX) for down-conversion of the RF signal to the first IF (IF) Second mixer (MIX2) for down-conversion of the IF to the second IF (IF2) IF amplifier (IFA) to amplify and limit the IF2 signal and for generation Phase coincidence demodulator (DEMOD) with third mixer (MIX3) to demodulate the IF signal Operational amplifier (OA) for data slicing, filtering and ASK detection Bias circuitry for bandgap biasing and circuit shutdown.2 EVB Technical Data Overview Input frequency range: 260 to 50 Power supply range: 2.3 V to 5.5 ASK 2.7 V to 5.5 FSK Temperature range: -40 C to +85 C Standby current: 50 na Operating current: 6.5 low gain mode 8.2 high gain mode Sensitivity: -0 ASK ) -04 FSK 2) Range of first IF: 0 to 80 Range of first IF2: 400 khz to 22 Maximum input level: -0 ASK 0 FSK Image rejection: > 65 db (e.g. with SAW front-end filter and at 0.7 IF2) Spurious emission: < -70 dbm Input frequency acceptance range: up to ±00 khz range: 70 db FSK deviation range: ±2.5 khz to ±80 khz ) at 4 kbps NRZ, BER = 3 0-3, 80 khz IF filter BW, incl. 3 db SAW front-end-filter loss 2) at 4 kbps NRZ, BER = 3 0-3, ± 20 khz FSK deviation, 80 khz IF filter BW, incl. 3 db SAW front-endfilter loss For more detailed information, please refer to the latest TH702 data sheet revision Page 3 of 4 EVB Description Rev. 02

4 EVB702 35/433 Receiver.3 Block Diagram _LNAC 2 GAIN_LNA 3 OUT_LNA 4 IN_MIX 5 _MIX IFP IFN _MIX OUT_MIX2 _IF IN_IFA 2 FBC OUT_IFA IN_DEM IN_LNA 3 LNA MIX LO IF MIX2 LO2 IF2 IFA MIX3 OUTP 23 OUTN _LNA 30 _LNA DIV8 DIV2 PFD VCO CP 29 LF BIAS PLL ENRX _BIAS 7 _BIAS OAP 20 OA OAN 9 8 Fig. : TH702 block diagram.4 Mode Configurations ENRX Mode Description 0 RX standby RX disabled RX active RX enable Note: ENRX are pulled down internally.5 LNA GAIN Control V GAIN_LNA Mode Description < 0.8 V HIGH GAIN LNA set to high gain >.4 V LOW GAIN LNA set to low gain Note: hysteresis between gain modes to ensure stability.6 Frequency Planning Frequency planning is straightforward for single-conversion applications because there is only one IF that can be chosen, and then the only possible choice is low-side or high-side injection of the LO signal (which is now the one and only LO signal in the receiver). The receiver s double-conversion architecture requires careful frequency planning. Besides the desired RF input signal, there are a number of spurious signals that may cause an undesired response at the output. Among them are the image of the RF signal (that must be suppressed by the RF front-end filter), spurious signals injected to the first IF (IF) and their images which could be mixed down to the same second IF (IF2) as the desired RF signal (they must be suppressed by the LC filter at IF and/or by low-crosstalk design) Page 4 of 4 EVB Description Rev. 02

5 EVB702 35/433 Receiver By configuring the TH702 for double conversion and using its internal PLL synthesizer with fixed feedback divider ratios of N = 8 (DIV_8) and N2 = 2 (DIV_2), four types of down-conversion are possible: low-side injection of LO and LO2 (low-low), LO low-side and LO2 high-side (low-high), LO high-side and LO2 lowside (high-low) or LO and LO2 high-side (high-high). The following table summarizes some equations that are useful to calculate the crystal reference frequency (REF), the first IF (IF) and the VCO or first LO frequency (LO), respectively, for a given RF and second IF (IF2). Injection type high-high low-low high-low low-high REF (RF IF2)/4 (RF IF2)/8 (RF + IF2)/4 (RF + IF2)/8 LO 6 REF 6 REF 6 REF 6 REF IF LO RF RF LO LO RF RF LO LO2 2 REF 2 REF 2 REF 2 REF IF2 LO2 IF IF LO2 IF LO2 LO2 IF.6. Selected Frequency Plans The following table depicts crystal, LO and image signals considering the examples of 35 and RF reception at IF2 = 0.7. The columns in bold depict the selected frequency plans to receive at 35 and , respectively. Signal type RF = 35 RF = 35 RF = 35 RF = 35 RF = RF = RF = RF = Injection type high-high low-low high-low low-high high-high low-low high-low low-high REF / LO / IF / LO2 / RF image/ IF image/ Maximum Frequency Coverage Parameter f min f max Injection type high-low low-low RF / REF / LO / IF / LO2 / IF2/ The selection of the reference crystal frequency is based on some assumptions. As for example: the first IF and the image frequencies should not be in a radio band where strong interfering signals might occur (because they could represent parasitic receiving signals), the LO signal should be in the range of 300 to 450 (because this is the optimum frequency range of the VCO). Furthermore the first IF should be as high as possible to achieve highest RF image rejection Page 5 of 4 EVB Description Rev. 02

6 EVB702 35/433 Receiver 2 Application Circuits 2. FSK Application Circuit 2.. Circuit Diagram for FSK Reception OUTP 2 2 FSK output 2 C5 C6 C7 XTAL C R5 R4 CB3 ENRX IN_LNA L 6 SAWFIL 3 4 C_ CB2 R L2 C ENRX 29 LF 30 3 IN_LNA 32 GAIN_LNA OUTP OAP OAN TH702 OUT_LNA IN_MIX IFP IFN 7 6 OUT_IFA 5 4 FBC2 3 FBC 2 IN_IFA 0 OUT_MIX2 9 C2 CERDIS CB4 C9 R2 C C0 CERFIL CB C7 C8 8 CB5 CB8 L3 L4 C6 L5 CB7 2CB6 Circuit Features Tolerates input frequency variations Well-suited for NRZ, Manchester and similar codes Page 6 of 4 EVB Description Rev. 02

7 EVB702 35/433 Receiver 2..2 Board Component Values for FSK Part Size Tolerance Description C pf 27 pf ±5% crystal series capacitor C nf nf ±0% loop filter capacitor C pf 4.7 pf ±5% LNA output tank capacitor C pf 2.2 pf ±5% MIX input matching capacitor C pf 27 pf ±5% IF tank capacitor C nf 33 nf ±0% IFA feedback capacitor C nf nf ±0% IFA feedback capacitor C 0603 nf nf ±0% IFA feedback capacitor C pf 0 pf ±5% DEMOD phase-shift capacitor C pf 00 pf ±5% demodulator output low-pass capacitor, this value for data rates < 20 kbps NRZ, for higher data rates decrease the value C nf.5 nf ±0% output low-pass capacitor C nf 0 nf ±0% data slicer capacitor, this value for data rates > 0.8 kbps NRZ, for lower data rates increase the value CB to CB5 de-coupling capacitor pf 330 pf ±0% CB7 to CB8 CB nf 33 nf ±0% de-coupling capacitor C_ pf 330 pf ±5% optional capacitor, to couple external signal R kω 0 kω ±5% loop filter resistor R Ω 330 Ω ±5% optional CERFIL output matching resistor R kω 330 kω ±5% data slicer resistor R kω 220 kω ±5% loading resistor L Ω 68 nh ±5% SAW filter matching inductor L nh 82 nh ±5% from Würth-Elektronik (WE-KI series), L nh 5 nh ±5% LNA output tank inductor from Würth-Elektronik (WE-KI series), L nh 00 nh ±5% IF tank inductor from Würth-Elektronik L nh 00 nh ±5% (WE-KI series), XTAL SAWFIL CERFIL CERDIS 6x3.5 HC49 3x3 3.45x3. 4.5x2 RF = 35 SAFDC35MSM0T00 (f 0 = ) SFECF0M7HA00 CDSCB0M7GA35 RF = SAFCC433MBL0X00 (f 0 = ) ±25ppm cal. ±30ppm temp. B 3dB = 840 khz B 3dB = 5 B 3dB = 80 khz fundamental-mode crystal from Telcona/Horizon (HEX22 series) fundamental-mode crystal, C load = 0 pf to 5pF, C 0, max = 7 pf, R, max = 50 Ωl low-loss SAW filter from Murata ceramic filter from Murata, ceramic discriminator from Murata, Page 7 of 4 EVB Description Rev. 02

8 EVB702 35/433 Receiver 2..3 Component Arrangement Top Side for FSK Reception Board size is 42.7mm x 37.5mm Melexis OUTN OUTP C5 R5 C6 R4 XTAL 0Ω C7 ENRX C- C CB3 0Ω C2 CERDIS RF_input L R C3 L2 CB TH CB4 C9 C C0 R2 IN_LNA EVB7XX_4 CB L3 C6 CB8 CB5 C7 C8 L4 L5 CB7 CB Page 8 of 4 EVB Description Rev. 02

9 EVB702 35/433 Receiver 2.2 ASK Application Circuit 2.2. Circuit Diagram for ASK Reception 2 ASK output 2 C6 C7 XTAL C R4 CB3 ENRX IN_LNA L 6 SAWFIL 3 4 C_ CB2 R L2 C ENRX 29 LF 30 3 IN_LNA 32 GAIN_LNA OUTP OAP OAN TH702 OUT_LNA IN_MIX IFP IFN 7 6 OUT_IFA 5 4 FBC2 3 FBC 2 IN_IFA 0 OUT_MIX2 9 CB4 C9 R2 C C0 CERFIL CB C7 C8 8 CB5 CB8 L3 L4 C6 L5 CB7 2CB Page 9 of 4 EVB Description Rev. 02

10 EVB702 35/433 Receiver Board Component Values for ASK Part Size Tolerance Description C pf 27 pf ±5% crystal series capacitor C nf nf ±0% loop filter capacitor C pf 4.7 pf ±5% LNA output tank capacitor C pf 2.2 pf ±5% MIX input matching capacitor C pf 27 pf ±5% IF tank capacitor C nf 33 nf ±0% IFA feedback capacitor C nf nf ±0% IFA feedback capacitor C 0603 nf nf ±0% IFA feedback capacitor C nf.5 nf ±0% output low-pass capacitor, this value for data rates < 0 kbps NRZ, for higher data rates decrease the value C nf 0 nf ±0% data slicer capacitor, this value for data rates > 0.8 kbps NRZ, for lower data rates increase the value CB to CB5 de-coupling capacitor pf 330 pf ±0% CB7 to CB8 CB nf 33 nf ±0% de-coupling capacitor C_ pf 330 pf ±5% optional capacitor, to couple external signal R kω 0 kω ±5% loop filter resistor R Ω 330 Ω ±5% optional CERFIL output matching resistor R kω 330 kω ±5% data slicer resistor L Ω 68 nh ±5% SAW filter matching inductor L nh 82 nh ±5% from Würth-Elektronik (WE-KI series), L nh 5 nh ±5% LNA output tank inductor from Würth-Elektronik (WE-KI series), L nh 00 nh ±5% IF tank inductor from Würth-Elektronik L nh 00 nh ±5% (WE-KI series), XTAL SAWFIL CERFIL 6x3.5 HC49 3x3 3.45x3. RF = 35 SAFDC35MSM0T00 (f 0 = ) SFECF0M7HA00 RF = SAFCC433MBL0X00 (f 0 = ) ±25ppm cal. ±30ppm temp. B 3dB = 840 khz B 3dB = 5 B 3dB = 80 khz fundamental-mode crystal from Telcona/Horizon (HEX22 series) fundamental-mode crystal, C load = 0 pf to 5pF, C 0, max = 7 pf, R, max = 50 Ωl low-loss SAW filters from Murata ceramic filter from Murata, Page 0 of 4 EVB Description Rev. 02

11 EVB702 35/433 Receiver Component Arrangement Top Side for ASK Reception Board size is 42.7mm x 37.5mm Melexis OUTN OUTP C6 C7 ENRX R4 XTAL C- C 0Ω CB3 RF_input L R C3 L2 CB TH CB4 C9 C C0 R2 IN_LNA EVB7XX_4 CB L3 C6 CB8 CB5 C7 C8 L4 L5 CB7 CB Page of 4 EVB Description Rev. 02

12 EVB702 35/433 Receiver 3 Evaluation Board Layouts Board layout data in Gerber format is available, board size is 37.5mm x 42.7mm. Melexis ENRX OUTN OUTP IN_LNA EVB7XX_4 Melexis PCB top view PCB bottom view Page 2 of 4 EVB Description Rev. 02

13 EVB702 35/433 Receiver 4 Package Description The device TH702 is RoHS compliant. D D A b E E e 32 9 c (0.0098) A2 A + 2 L.0 (.004) Fig. 2: LQFP32 (Low profile Quad Flat Package) All Dimension in mm, coplanaríty < 0.mm E, D E, D A A A2 e b c L α min max All Dimension in inch, coplanaríty < min max Soldering Information The device TH702 is qualified for MSL3 with soldering peak temperature 260 deg C according to JEDEC J-STD Page 3 of 4 EVB Description Rev. 02

14 EVB702 35/433 Receiver 5 Disclaimer ) The information included in this documentation is subject to Melexis intellectual and other property rights. Reproduction of information is permissible only if the information will not be altered and is accompanied by all associated conditions, limitations and notices. 2) Any use of the documentation without the prior written consent of Melexis other than the one set forth in clause is an unfair and deceptive business practice. Melexis is not responsible or liable for such altered documentation. 3) The information furnished by Melexis in this documentation is provided as is. Except as expressly warranted in any other applicable license agreement, Melexis disclaims all warranties either express, implied, statutory or otherwise including but not limited to the merchantability, fitness for a particular purpose, title and non-infringement with regard to the content of this documentation. 4) Notwithstanding the fact that Melexis endeavors to take care of the concept and content of this documentation, it may include technical or factual inaccuracies or typographical errors. Melexis disclaims any responsibility in connection herewith. 5) Melexis reserves the right to change the documentation, the 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. 6) 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 information in this documentation. 7) The product described in this documentation is intended for use in normal commercial applications. Applications requiring operation beyond ranges specified in this documentation, 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. 8) Any supply of products by Melexis will be governed by the Melexis Terms of Sale, published on Melexis NV. All rights reserved. For the latest version of this document, go to our website at: Or for additional information contact Melexis Direct: Europe, Africa: Americas: Asia: Phone: Phone: Phone: sales_europe@melexis.com sales_usa@melexis.com sales_asia@melexis.com ISO/TS 6949 and ISO400 Certified Page 4 of 4 EVB Description Rev. 02