EVB71112 868/915MHz Receiver Evaluation Board Description Features Double-conversion superhet architecture for low 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 RSSI allows signal strength indication and ASK detection Ordering Information Part No. EVB71112-868-FSK-C EVB71112-868-ASK-C EVB71112-915-FSK-C EVB71112-915-ASK-C * EVB71112-XXX-YYY-C with XXX = Reception frequency (868.3MHz or 915MHz) and YYY = Modulation (FSK or ASK). ** The evaluation board is supplied with a SMA connector. Application Examples Evaluation Board 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 TH71112 FSK/ASK double-conversion superheterodyne receiver 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 750 MHz to 990 MHz (e.g. for applications to FCC part 15). 39012 71112 01 Rev. 012 Page 1 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description Document Content 1 Theory of Operation ...................................................................................................3 1.1 General ............................................................................................................................. 3 1.2 EVB Technical Data Overview ......................................................................................... 3 1.3 Block Diagram .................................................................................................................. 4 1.4 Mode Configurations ........................................................................................................ 4 1.5 LNA GAIN Control ............................................................................................................ 4 1.6 Frequency Planning.......................................................................................................... 4 1.6.1 1.6.2 2 Selected Frequency Plans........................................................................................................... 5 Maximum Frequency Coverage................................................................................................... 5 Application Circuits ...................................................................................................6 2.1 2.1.1 2.1.2 2.1.3 2.2 2.2.1 2.2.2 2.2.3 FSK Application Circuit ..................................................................................................... 6 Circuit Diagram for FSK Reception.............................................................................................. 6 Board Component Values for FSK .............................................................................................. 7 Component Arrangement Top Side for FSK Reception .............................................................. 8 ASK Application Circuit..................................................................................................... 9 Circuit Diagram for ASK Reception ............................................................................................. 9 Board Component Values for ASK ............................................................................................ 10 Component Arrangement Top Side for ASK Reception ............................................................ 11 3 Evaluation Board Layouts .......................................................................................12 4 Package Description ................................................................................................13 4.1 5 Soldering Information ..................................................................................................... 13 Disclaimer .................................................................................................................14 39012 71112 01 Rev. 012 Page 2 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 1 Theory of Operation 1.1 General With the TH71112 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 RSSI signal is fed to an ASK detector, which is constituted by the operational amplifier. The superheterodyne configuration is double conversion where MIX1 and MIX2 are driven by the internal local oscillator signals LO1 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 TH71111, is also available. Both Receiver ICs have the same die. At the TH71111 the second mixer MIX2 operates as an amplifier. The TH71112 receiver IC consists of the following building blocks: 1.2 PLL synthesizer (PLL SYNTH) for generation of the first and second local oscillator signals LO1 and LO2, parts of the PLL SYNTH are: the high-frequency VCO1, the feedback dividers DIV_16 and DIV_2, a phase-frequency detector (PFD) with charge pump (CP) and a crystal-based reference oscillator (RO) Low-noise amplifier (LNA) for high-sensitivity RF signal reception First mixer (MIX1) for down-conversion of the RF signal to the first IF (IF1) Second mixer (MIX2) for down-conversion of the IF1 to the second IF (IF2) IF amplifier (IFA) to amplify and limit the IF2 signal and for RSSI 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 EVB Technical Data Overview Input frequency range: 750 MHz to 990 MHz Power supply range: 2.3 V to 5.5 V @ ASK 2.7 V to 5.5 V @ FSK Temperature range: -40 °C to +85 °C Standby current: 50 nA Operating current: 7.5 mA @ low gain mode 9.2 mA @ high gain mode Sensitivity: -109 dBm @ ASK 1) -103 dBm @ FSK 2) Range of first IF1: 10 MHz to 80 MHz Range of first IF2: 400 kHz to 22 MHz Maximum input level: -10 dBm @ ASK 0 dBm @ FSK Image rejection: > 60 dB (e.g. with 868.3 MHz SAW front-end filter and at 10.7 MHz IF2) Spurious emission: < -70 dBm Input frequency acceptance range: up to ±100 kHz RSSI range: 70 dB FSK deviation range: ±2.5 kHz to ±80 kHz 1) at 4 kbps NRZ, BER = 3⋅10-3, 180 kHz IF filter BW, incl. 3 dB SAW front-end-filter loss 2) at 4 kbps NRZ, BER = 3⋅10-3, ± 20 kHz FSK deviation, 180 kHz IF filter BW, incl. 3 dB SAW front-endfilter loss For more detailed information, please refer to the latest TH71112 data sheet revision 39012 71112 01 Rev. 012 Page 3 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description IN_LNA 31 MIX1 21 14 15 16 MIX2 OUTP MIX3 IF2 IF1 LNA IN_DEM 13 OUT_IFA 12 RSSI 11 FBC1 10 IN_IFA 9 VEE_IF 8 OUT_MIX2 7 VCC_MIX 6 IF1N 5 IF1P 4 VEE_MIX 3 IN_MIX1 2 OUT_LNA 1 GAIN_LNA Block Diagram VEE_LNAC 1.3 23 IFA OUTN 24 LO2 LO1 OAP OA 19 PFD OUT_OA RO Fig. 1: 1.4 25 27 28 ENRX 26 RO VCC_PLL 29 LF VEE_RO 30 18 BIAS CP VEE_LNA VCC_LNA VCO1 22 17 VCC_BIAS DIV2 VEE_BIAS DIV16 32 20 OAN TH71112 block diagram Mode Configurations ENRX Mode Description 0 RX standby RX disabled 1 RX active RX enable Note: ENRX are pulled down internally 1.5 LNA GAIN Control VGAIN_LNA Mode Description < 0.8 V HIGH GAIN LNA set to high gain > 1.4 V LOW GAIN LNA set to low gain Note: hysteresis between gain modes to ensure stability 1.6 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 (IF1) 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 IF1 and/or by low-crosstalk design). 39012 71112 01 Rev. 012 Page 4 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description By configuring the TH71112 for double conversion and using its internal PLL synthesizer with fixed feedback divider ratios of N1 = 16 (DIV_16) and N2 = 2 (DIV_2), four types of down-conversion are possible: low-side injection of LO1 and LO2 (low-low), LO1 low-side and LO2 high-side (low-high), LO1 high-side and LO2 low-side (high-low) or LO1 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 (IF1) and the VCO1 or first LO frequency (LO1), respectively, for a given RF and second IF (IF2). Injection type high-high low-low high-low low-high REF (RF – IF2)/30 (RF – IF2)/34 (RF + IF2)/30 (RF + IF2)/34 LO1 32•REF 32•REF 32•REF 32•REF IF1 LO1 – RF RF – LO1 LO1 – RF RF – LO1 LO2 2•REF 2•REF 2•REF 2•REF IF2 LO2 – IF1 IF1 – LO2 IF1 – LO2 LO2 – IF1 1.6.1 Selected Frequency Plans The following table depicts crystal, LO and image signals considering the examples of 868.3 MHz and 915 MHz RF reception at IF2 = 10.7 MHz. The columns in bold depict the selected frequency plans to receive at 868.3 MHz and 915 MHz, respectively. Signal type RF = 868.3 MHz Injection type high-high RF = 868.3 MHz RF = 868.3 MHz RF = 868.3 MHz RF = 915 MHz RF = 915 MHz RF = 915 MHz RF = 915 MHz low-low high-low low-high high-high low-low high-low low-high REF / MHz 28.58667 25.22353 29.3 25.85294 30.14333 26.59706 30.85667 27.22647 LO1 / MHz 914.77333 807.15294 937.6 827.29412 964.58667 851.10588 987.41333 871.24706 IF1 / MHz 46.47333 61.14706 69.3 41.00588 49.58667 63.89412 72.41333 43.75294 LO2 / MHz 57.17333 50.44706 58.6 51.70588 60.28667 53.19412 61.71333 54.45294 RF image/MHz 961.24667 746.00588 1006.9 786.28824 1014.17 787.21176 1059.83 827.49412 IF1 image/MHz 39.74706 47.9 62.40588 70.98667 42.49412 51.01333 65.15294 1.6.2 67.87333 Maximum Frequency Coverage Parameter fmin fmax Injection type high-low low-low RF / MHz 739.3 998.825 REF / MHz 25.0 29.0625 LO1 / MHz 800 930 IF1 / MHz 60.7 68.825 LO2 / MHz 50.0 58.125 IF2/ MHz 10.7 10.7 39012 71112 01 Rev. 012 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 LO1 signal should be in the range of 800 MHz to 930 MHz (because this is the optimum frequency range of the VCO1). Furthermore the first IF should be as high as possible to achieve highest RF image rejection. Page 5 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 2 Application Circuits 2.1 FSK Application Circuit RSSI GND OUT_OA GND Circuit Diagram for FSK Reception OUTP GND 2.1.1 1 2 1 2 1 2 FSK output C16 C15 C17 R4 R5 XTAL CB3 VCC VCC 17 OAN 19 OAP 20 VEE 22 IN_MIX1 VEE IF1P IF1N VCC 1 2 3 4 5 6 7 8 32 VCC C5 CB1 R2 C10 VEE 10 OUT_LNA 31 IN_LNA C11 FBC1 12 IN_IFA 11 30 VEE L2 CB4 C9 GAIN_LNA C4 TH71112 29 LF VCC FBC2 13 VEE 50 L1 6 1 SAWFIL 3 4 C3 C12 VCC 14 28 ENRX R1 IN_LNA 16 27 VCC CB2 CERDIS OUT_IFA 15 26 RO 1 2 3 VCC ENRX GND 25 VEE C_RO OUT_OA 18 VCC RSSI 21 24 1 2 GND RO OUTP 23 C1 OUT_MIX2 9 CERFIL C8 C7 L5 L4 CB5 VCC CB8 2 1 CB6 L3 GND VCC CB7 Circuit Features • • Tolerates input frequency variations Well-suited for NRZ, Manchester and similar codes 39012 71112 01 Rev. 012 Page 6 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 2.1.2 Board Component Values for FSK Part Size Value @ 868.3 MHz Value @ 915 MHz Tolerance Description C1 0805 22 pF 22 pF ±5% crystal series capacitor C3 0603 1 nF 1 nF ±10% loop filter capacitor C4 0603 4,7 pF NIP ±5% capacitor to match SAW filter input C5 0603 2.7 pF NIP ±5% capacitor to match SAW filter output C7 0603 1.0 pF 0.68 pF ±5% MIX1 input matching capacitor C8 0603 22 pF 22 pF ±5% IF1 tank capacitor C9 0603 33 nF 33 nF ±10% IFA feedback capacitor C10 0603 1 nF 1 nF ±10% IFA feedback capacitor C11 0603 1 nF 1 nF ±10% IFA feedback capacitor C12 0805 10 pF 10 pF ±5% DEMOD phase-shift capacitor C15 0805 100 pF 100 pF ±5% demodulator output low-pass capacitor, this value for data rates < 20 kbps NRZ, for higher data rates decrease the value C16 0805 1.5 nF 1.5 nF ±10% RSSI output low-pass capacitor C17 0805 10 nF 10 nF ±10% data slicer capacitor, this value for data rates > 0.8 kbps NRZ, for lower data rates increase the value CB1 to CB5 CB7 to CB8 0603 330 pF 330 pF ±10% de-coupling capacitor CB6 0805 33 nF 33 nF ±10% de-coupling capacitor C_RO 0603 330 pF 330 pF ±5% optional capacitor, to couple external RO signal R1 0603 10 kΩ 10 kΩ ±5% loop filter resistor R2 0603 330 Ω 330 Ω ±5% optional CERFIL output matching resistor R4 0805 330 kΩ 330 kΩ ±5% data slicer resistor R5 0805 220 kΩ 220 kΩ ±5% loading resistor L1 0603 22 nH 0Ω ±5% L2 0603 22 nH 0Ω ±5% SAW filter matching inductor from Würth-Elektronik (WE-KI series), or equivalent part L3 0603 10 nH 10 nH ±5% LNA output tank inductor from Würth-Elektronik (WE-KI series), or equivalent part L4 0805 100 nH 100 nH ±5% L5 0805 100 nH 100 nH ±5% IF1 tank inductor from Würth-Elektronik (WE-KI series), or equivalent part 25.22353 MHz @ RF = 868.3 MHz 26.59706 MHz @ RF = 915 MHz ±25ppm cal. ±30ppm temp. XTAL SMD 6x3.5 HC49 SMD SAWFIL CERFIL CERDIS SMD 3x3 SMD 3.8x3.8 SMD 3.45x3.1 SMD 4.5x2 39012 71112 01 Rev. 012 SAFCC868MSL0X00 (f0 =868.3 MHz) B3dB = 2 MHz SAFCH915MAL0N00 (f0 = 915 MHz) SFECF10M7HA00 fundamental-mode crystal from Telcona/Horizon (HEX22 series) or equivalent part fundamental-mode crystal, Cload = 10 pF to 15 pF, C0, max = 7 pF, R1, max = 50 Ωl low-loss SAW filter from Murata or equivalent part B3dB = 40 MHz B3dB = 180 kHz CDSCB10M7GA135 ceramic filter from Murata, or equivalent part ceramic discriminator from Murata, or equivalent part Page 7 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 2.1.3 Component Arrangement Top Side for FSK Reception 1 OUT_OA RSSI OUTP Melexis OUTN Board size is 42.7mm x 37.5mm 1 C16 C15 1 R5 1 0Ω 17 16 C5 C4 L2 32 1 C12 C11 R2 C9 CB2 TH71112 L1 0Ω CB4 24 25 C3 R1 RF_input CB3 C1 C-RO CERDIS C17 1 ENRX RO R4 XTAL C10 8 9 CB1 CB5 C7 Page 8 of 14 VCC 1 CB6 L5 CB7 L4 CB8 EVB711XX_4 39012 71112 01 Rev. 012 C8 L3 IN_LNA EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description Circuit Diagram for ASK Reception OUT_OA GND 2.2.1 ASK Application Circuit RSSI GND 2.2 1 2 1 2 ASK output C16 R4 C17 CB3 VCC XTAL 28 ENRX VCC 17 OAN 19 OAP 20 VEE 22 TH71112 29 LF IN_IFA 11 IN_MIX1 VEE IF1P IF1N VCC 1 2 3 4 5 6 7 8 32 VCC C5 CB1 R2 C10 VEE 10 OUT_LNA 31 IN_LNA C11 FBC1 12 30 VEE L2 CB4 C9 GAIN_LNA C4 C3 VCC FBC2 13 VEE L1 50 CB2 6 1 SAWFIL 3 4 VCC 14 27 VCC R1 IN_LNA 16 OUT_IFA 15 26 RO 1 2 3 VCC ENRX GND 25 VEE C_RO OUT_OA 18 VCC RSSI 21 24 1 2 GND RO OUTP 23 C1 OUT_MIX2 9 CERFIL C8 C7 L5 L4 CB5 VCC 39012 71112 01 Rev. 012 CB8 Page 9 of 14 2 1 CB6 L3 GND VCC CB7 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 2.2.2 Board Component Values for ASK Part Size Value @ 868.3 MHz Value @ 915 MHz C1 0805 22 pF 22 pF ±5% crystal series capacitor C3 0603 1 nF 1 nF ±10% loop filter capacitor C4 0603 4,7 pF NIP ±5% capacitor to match SAW filter input C5 0603 2.7 pF NIP ±5% capacitor to match SAW filter output C7 0603 1.0 pF 0.68 pF ±5% MIX1 input matching capacitor C8 0603 22 pF 22 pF ±5% IF1 tank capacitor C9 0603 33 nF 33 nF ±10% IFA feedback capacitor C10 0603 1 nF 1 nF ±10% IFA feedback capacitor C11 0603 1 nF 1 nF ±10% IFA feedback capacitor C16 0805 1.5 nF 1.5 nF ±10% RSSI output low-pass capacitor, this value for data rates < 10 kbps NRZ, for higher data rates decrease the value C17 0805 10 nF 10 nF ±10% data slicer capacitor, this value for data rates > 0.8 kbps NRZ, for lower data rates increase the value CB1 to CB5 CB7 to CB8 0603 330 pF 330 pF ±10% de-coupling capacitor CB6 0805 33 nF 33 nF ±10% de-coupling capacitor C_RO 0603 330 pF 330 pF ±5% optional capacitor, to couple external RO signal R1 0603 10 kΩ 10 kΩ ±5% loop filter resistor R2 0603 330 Ω 330 Ω ±5% optional CERFIL output matching resistor R4 0805 330 kΩ 330 kΩ ±5% data slicer resistor L1 0603 22 nH 0Ω ±5% L2 0603 22 nH 0Ω ±5% SAW filter matching inductor from Würth-Elektronik (WE-KI series), or equivalent part L3 0603 10 nH 10 nH ±5% LNA output tank inductor from Würth-Elektronik (WE-KI series), or equivalent part L4 0805 100 nH 100 nH ±5% L5 0805 100 nH 100 nH ±5% IF1 tank inductor from Würth-Elektronik (WE-KI series), or equivalent part XTAL SMD 6x3.5 HC49 SMD SAWFIL CERFIL SMD 3x3 SMD 3.8x3.8 SMD 3.45x3.1 39012 71112 01 Rev. 012 25.22353 MHz @ RF = 868.3 MHz 26.59706 MHz @ RF = 915 MHz SAFCC868MSL0X00 (f0 =868.3 MHz) Tolerance ±25ppm cal. ±30ppm temp. B3dB = 2 MHz SAFCH915MAL0N00 (f0 = 915 MHz) SFECF10M7HA00 Description fundamental-mode crystal from Telcona/Horizon (HEX22 series) or equivalent part fundamental-mode crystal, Cload = 10 pF to 15 pF, C0, max = 7 pF, R1, max = 50 Ωl low-loss SAW filters from Murata or equivalent part B3dB = 40 MHz B3dB = 180 kHz Page 10 of 14 ceramic filter from Murata, or equivalent part EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 2.2.3 Component Arrangement Top Side for ASK Reception OUT_OA RSSI OUTP 1 C16 1 1 XTAL C17 17 16 L2 C5 C4 TH71112 L1 32 1 R2 C9 CB2 C11 CB4 24 25 C3 R1 RF_input CB3 C1 C-RO 0Ω 1 ENRX RO R4 Melexis OUTN Board size is 42.7mm x 37.5mm C10 8 9 CB1 CB5 C7 Page 11 of 14 VCC 1 CB6 L5 CB7 L4 CB8 EVB711XX_4 39012 71112 01 Rev. 012 C8 L3 IN_LNA EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 3 Evaluation Board Layouts VCC Board layout data in Gerber format is available, board size is 37.5mm x 42.7mm. OUT_OA RSSI OUTP EVB711XX_4 IN_LNA ENRX RO Melexis OUTN 39012 71112 01 Rev. 012 Melexis PCB top view PCB bottom view Page 12 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 4 Package Description The device TH71112 is RoHS compliant. D D1 A 24 17 16 25 b E e E1 32 9 1 8 A2 A1 12° +1° 0.25 (0.0098) c 12° +1° L Fig. 2: .10 (.004) LQFP32 (Low profile Quad Flat Package) All Dimension in mm, coplanaríty < 0.1mm E1, D1 E, D A A1 A2 e b c L α 7.00 9.00 1.40 1.60 0.05 0.15 1.35 1.45 0.8 0.30 0.45 0.09 0.20 0.45 0.75 0° 7° 0.053 0.057 0.031 0.012 0.018 0.0035 0.0079 0.018 0.030 0° 7° min max All Dimension in inch, coplanaríty < 0.004” min max 4.1 0.276 0.354 0.055 0.063 0.002 0.006 Soldering Information • 39012 71112 01 Rev. 012 The device TH71112 is qualified for MSL3 with soldering peak temperature 260 deg C according to JEDEC J-STD-2. Page 13 of 14 EVB Description April/08 EVB71112 868/915MHz Receiver Evaluation Board Description 5 Disclaimer 1) 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 1 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 www.melexis.com. © 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, Africa: Americas: Asia: Phone: +32 1367 0495 E-mail: [email protected] Phone: +1 603 223 2362 E-mail: [email protected] Phone: +32 1367 0495 E-mail: [email protected] ISO/TS 16949 and ISO14001 Certified 39012 71112 01 Rev. 012 Page 14 of 14 EVB Description April/08