50MHz INPUT MIXER AND 450kHz FM IF DEMODULATOR IC

Transcription

1 5MHz INPUT MIXER AND 45kHz FM IF DEMODULATOR IC GENERAL DESCRIPTION PACKAGE LINE The NJM2593 is an FM IF demodulator IC with 45kHz (standard) IF frequency, which operates from 1.8V to 9V supply, lowcurrent. It includes an oscillator, mixer, limiting amplifier, quadrature detector, active filter, and FSK comparator. The NJM2593 also has a circuit and comparator for carrier sense. NJM2593V FEATURES Wide Operating Voltage 1.8V to 9.V Low Operating Current 1.2mA type. at V =2.V, external local oscillator input Maximum Mixer Input Signal Frequency 5MHz (reference value) Mixer Input Resistance 4.5kΩ (reference value) IF Frequency 45kHz (standard) Conventional Quadrature Detector External Phaseshifting Capacitor External Discriminator or LC Resonant Circuit Comparator with OpenCollector Output Quick Charge/Discharge Circuit for FSK Reference Voltage Bipolar Technology Package Outline SSOP2 BLOCK DIAGRAM MIX IN GND LEVEL CARRIER FSK SW LPF LPF IN AF OSC MIXER BUFFER COMP FSK COMP IF AMP FILTER AMP OSC (B) OSC (E) MIX V IF IN DEC FSK VREF1 FSK VREF2 IF QUAD IN QUAD DET Ver

2 ABSOLUTE MAXIMUM RATINGS (Ta=25 C) PARAMETER SYMBOL RATINGS UNIT Supply Voltage V 1. V Power Dissipation P d 3 mw Operating Temperature T o p r 4 to 85 C Storage Temperature T s t g 4 to 125 C RECOMMENDED OPERATING CONDITION (Ta=25 C) PARAMETER SYMBOL TEST CONDITIONS MIN. TYP. MAX. UNIT Supply Voltage V V ELECTRICAL CHARACTERISTICS (Ta=25 C, V =2.V, fmix=21.7mhz, flo=21.25mhz, fif=45khz, fmod=6hz, fdev=±2khz, unless otherwise noted) PARAMETER SYMBOL TEST CONDITIONS MIN. TYP. MAX. UNIT Current Consumption I c c q No signal ma Mixer Conversion Gain G m i x VinMIX=6dBuVEMF, Measured at Pin3, without IF filter, with 1.8kΩ.1uF db Mixer 3 rd Order Intercept IP3 95 dbuv Mixer Input Resistance R i n M 4.5 kω Mixer Input Capacitance C i n M 2. pf Mixer Output Resistance R o M 1.8 kω Signal to Noise Ratio 1 S / N 1 Signal to Noise Ratio 2 S / N 2 Signal to Noise Ratio 3 S / N 3 Mixer input VinMIX=6dBuVEMF IF input VinIF=6dBuVEMF IF input VinIF=25dBuVEMF 6 db db db 3dB Limiting Sensitivity V i n ( l i m ) IF input 22 dbuvemf AM Rejection Ratio A M R IF input, AM=3% VinIF=6dBuVEMF 5 db IF Amplifier Input Resistance R i n I F 1.8 kω Output Voltage V r s s i IF input VinIF=4dBuVEMF V 2 Ver.21839

3 PARAMETER SYMBOL TEST CONDITIONS MIN. TYP. MAX. UNIT Demodulated Output Level Duty Ratio of Wave Shaped Output Quick Charge/Discharge Current High Level Leak Current of CARRIER Terminal Low Level Voltage of CARRIER Terminal Bias Current of LEVEL Terminal High Level Leak Current of FSK Terminal Low Level Voltage of FSK Terminal V o d DR Ich IF input VinIF =6dBuVEMF IF Input VinIF=6dBuVEMF FSK REF=GND LPF=.4V mvrms % ua IcryH V CARRIER =V. ua VcryL I CARRIER =1uA.1.4 V I l e v e l V CARRIER =.8V. ua I f s k H V FSK =V. ua V f s k L I FSK =1uA.1.4 V Ver

4 TEST CIRCUIT This test circuit allows the measurement of all parameters described in ELECTRICAL CHARACTERISTICS. This test circuit includes some electrical switches that should be in the suitable position for the measurement of each parameter. Test Circuit 1 (except for Gmix) LEVEL CARRIER FSK AF V SWITCH Hi Lo.1u 68k RF IN 21.7MHz 1p 1p 1k 1k 56p 68k 68k p LO IN 21.25MHz 1p OSC MIXER BUFFER 1p COMP FSK COMP IF AMP IF IN 45kHz FILTER AMP OPEN IF FILTER V 1u.1u.1u B A IF SW 1u C1 R1 QUAD DET 1u CD V Test Circuit 2 (for Gmix) LEVEL CARRIER FSK AF V SWITCH Hi Lo.1u 68k RF IN 21.7MHz 1p 1p 1k 1k 56p 68k 68k p LO IN 21.25MHz 1p OSC MIXER BUFFER 1p COMP FSK COMP IF AMP IF IN 45kHz FILTER AMP MIX.1u 1.8k IF FILTER V 1u.1u.1u B A IF SW 1u C1 R1 QUAD DET 1u CD V 4 Ver.21839

5 External components CD : Ceramic Discriminator, 45kHz IF FILTER : Ceramic Filter, 45kHz Measurement condition Condition1 is the condition for the case of IF input : IF SW : in the A position. IF IN input signal : input frequency(fif) = 45kHz, input level(vinif)= 6dBuVEMF, modulation frequency(fmod)=6hz, deviation fdev=±2khz Condition 2 is the condition for the case of Mixer Input : IF SW : in the B position MIX IN input signal: input frequency(fmix)=21.7mhz, input level(vinmix)=6dbuvemf, modulation frequency(fmod)=6hz, deviation fdev=±2khz OSC(E)input signal: input frequency(fosc)=21.25mhz, input level(vinosc)=15dbuvemf Ver

6 TERMINAL FUNCTION (Ta=25 C, V =2.V) Pin No. SYMBOL EQUIVARENT CIRCUIT VOLTAGE FUNCTION 1 OSC (B) V 1.98V 2k OSC (E) 8u 1.28V Base / Emitter Terminal Colpitts type oscillator is formed with an external oscillator element of crystal unit or SAW resonator. Output of an external oscillator circuit can also input to pin1 or pin2. V 1k Mixer Output An external 45kHz ceramic filter is connected. The typical output impedance is 2kΩ. 3 MIX 1.1k 2p 1.18V 3 1u 4 V V 5 IF IN 5k 1.96V DEC 1.96V Supply Voltage IF Limiter Amplifier Input This is an input to the IF amplifier after passing through 45kHz ceramic filter. The typical input impedance is 1.8kΩ. IF Decoupling An external decoupling capacitor is connected to enhance stability. 7 FSK VREF1.46V 7 V FSK Reference Input This pin is an input of reference voltage for FSK comparator. An external capacitor is connected to create an average DC level of FM demodulated signal. The choice of this capacitor is dependent on the speed of data signal. A quick charge/discharge circuit offers the voltage of pin 7 comes the same voltage of pin 11 quickly. 6 Ver.21839

7 Pin No. SYMBOL EQUIVARENT CIRCUIT VOLTAGE FUNCTION 8 FSK VREF2.44V 8 V FSK Reference Voltage Output This pin usually keeps open. This fixed output voltage may be available for the FSK reference voltage of wave shaping comparator by connecting to pin7. This usage is effective in shaping the data signal with continuous bits of the same polarity, and discussed in another document related to applications information. V IF Output An external phase shifting capacitor is connected between pin9 and pin1. 9 IF 1.14V 9 4u V Quadrature Detector Input An external phase shifting coil or ceramic discriminator is connected QUAD IN 1.99V V FM Demodulated Signal Output An external 3rd order multiple feed back filter (RC filter) is connected between pin11 and pin AF.44V 11 18u Ver

8 Pin No. SYMBOL EQUIVARENT CIRCUIT VOLTAGE FUNCTION 12 LPF IN 6u.45V LPF.45V V Low Pass Filter Input An external RC components forms a band pass filter between pin12 and pin13. This terminal is biased from pin 11 though an external RC filter. Low Pass Filter Output 14 SW 14 3k V Quick Charge / Discharge Control The power supply output voltage to pin 14 sets up the quick charge / discharge circuit. Hi : ON Low : OFF Instead of V, another power source can also be used within the limit of the rated supply voltage. V 6u FSK FSK Output The FSK comparator is a wave shaping circuit. A Filter Amplifier output signal is inverted and wave shaped. Instead of V, another power source can also be used within the limit of the rated supply voltage. 16 CARRIER 16 3u Carrier Sense Output This pin outputs the result of comparator by comparing output level with an external input level to pin Ver.21839

9 Pin No. SYMBOL EQUIVARENT CIRCUIT VOLTAGE FUNCTION 17.2V 17 5k V Received Signal Strength Indicator Output Pin 11 outputs DC level proportional to the log of input signal level to pin 2. V Sense Level Input External reference voltage of comparator 18 LEVEL GND Ground Mixer Input The mixer is designed to work up to 47MHz with the typical input impedance of RinM = 4.5kΩ and CinM = 2pF(at 21.7MHz). 2 MIX IN 5k 5k 1.3V 2 2p Note : 1. ESD protection diodes exist between each of the following pins and V. Pin 1,2,3,5,6,7,8,9,1,11,12,13,17,18,2 2. ESD protection diodes also exist between each of the following pins and ground. Pin 1,2,3,5,6,7,8,9,1,11,12,13,14,15,16,17,18 Ver

10 APPLICATION CIRCUIT Local Oscillator with External Crystal and LC Resonant Elements CARRIER FSK 1st IF V V SWITCH Hi Lo OSC MIXER BUFFER V FSK COMP C DEC C REF FILTER AMP COMP NJM2593 IF AMP QUAD DET DET Tank V IF Filter External Local Oscillator Signal Input CARRIER FSK 1st IF V V SWITCH Hi Lo OSC MIXER BUFFER COMP V FSK COMP IF AMP C DEC C REF FILTER AMP NJM2593 DET Tank QUAD DET V External Oscillator IF Filter 1 Ver.21839

11 EVALUATION PC BOARD The evaluation board is useful for your design and to have more understanding of the usage and performance of this device. This circuit is the same as TEST CIRCUIT. Note that this board is not prepared to show the recommendation of pattern and parts layout. Circuit Diagram LEVEL CARRIER FSK SW Hi Lo AF V C6 R4 68k RF IN R11 R6 1k R5 1k.1 R2 68k C1 C9 C7 1p 1 56p p R3 68k C8 33p LO IN R8 OSC MIXER BUFFER COMP FSK COMP FILTER AMP C p V C1 1p NC IF FILTER C13 1u C2.1u B A C2 Position IF AMP C4.1u R9 C12 1u IF IN NC C5 22p CD QUAD DET R1 3.3k V Note: 1. This board is designed for mixerinput type and C2 is factoryconfigured as follows: C2 : in the B position For the case of IFinput type, the position of C2 is necessary to change as follows: C2 : in the A position The actual position of C2 is shown in the next page. 2. External components CD : Ceramic Discriminator, 45kHz IF FILTER : Ceramic Filter, 45kHz Ver

12 Circuit Side View LO IN RF IN R8 B Position C1 C1 R11 LEVEL IF IN R9 C2 C2 C12 C4 C5 IC1 NJM2593 C7 R2 R4 C6 C9 A Position CD CARRIER SW V AF FSK Ground Side View CF C3 R1 C8 R3 R6 R5 NJM2593 Hi : Charge ON Lo: Charge OFF C13 C12 Note: 1. External Components C1, C3, C9, C1=1pF C2, C4=.1uF C5=18pF C6=.1uF C7=56p C8=33pF C12, C13=1uF R1=3.3kΩ R2, R3, R4=68kΩ R5, R6=1kΩ R8, R9, R11=Ω CF : Ceramic Filter, 45kHz CD : Ceramic Discriminator, 45kHz 12 Ver.21839

13 TYPICAL CHARACTERISTICS ( Ta=25 C, V =2.V, unless otherwise noted ) Current Consumption versus Supply Voltage Mixer Conversion Gain versus Supply Voltage 1.5 No Input signal 3 Measured at Pin3,terminated with 1.8kΩ and.1uf Current Consumption Iccq(mA) 1..5 Mixer Conversion Gain Gmix(dB) Fmix=21.7MHz Supply Voltage V(V) Supply Voltage V(V) Demodulated Output versus Supply Voltage FSK Duty Ratio vesus Supply Voltage 15 Condition 1(IF input) 6 Condition 1(IF input) Demodulated Output Level Vod(mVrms) Duty Ratio of Wave Shaped Output(%) SW=OFF SW=ON Supply Voltage V(V) Supply Voltage V(V) S/N versus Supply VoltageMixer Input 3dB Limiting Sensitivity versus Supply Voltage 8 Condition 2(Mixer input) 3 Condition 1(IF input) Signal to Noise Ratio S/N1(dB) Limiting Sensitivity Vin(lim)(dBuVEMF) Supply Voltage V(V) Supply Voltage V(V) Ver

14 Mixer Conversion Gain versus Frequency 3 Measured at Pin3,terminated with 1.8kΩ and.1uf Mixer Conversion Gain Gmix(dB) Mixer Input Frequency fmix(mhz) Mixer Conversion Gain versus OSC Input AF Output versus Frequency:SCurve 3 Measured at Pin3,terminated with 1.8kΩ and.1uf 12 Condition 1(IF input) Mixer Conversion Gain Gmix(dB) Fmix=21MHz Fmix=5MHz AF Output Voltage(mV) Local OSC Input Level (dbuv) IF Frequency fif(khz) IF Detuning Characterisitics Carrier Sense Characteristics 5 Condition 1(IF input) 2.4 Condition 1(IF input), LEVEL=.8V IF Detuning(dB) Comparator Output Voltage(V) IF Frequency fif(khz) Output Voltage Vrssi(V) 14 Ver.21839

15 SN,N,AMR versus Mixer Input SN,N,AMR versus IF Input 1 Condition 2(Mixer input),am=3% 1 Condition 1(IF input),am=3% 1 SN 1 SN SN,N,AMR(dB) AMR SN,N,AMR(dB) AMR 6 7 N 6 7 N Mixer Input Level VinMIX(dBuVEMF) IF Input Level VinIF(dBuVEMF) Output versus Mixer Input Output versus IF Input 2. Condition 2(Mixer input) 2. Condition 1(IF input) 1.8 V=2.V 1.8 V=2.V Output Voltage Vrssi(V) Output Voltage Vrssi(V) Mixer Input Level VinMIX(dBuVEMF) IF Input Level VinIF(dBuVEMF) Mixer Conversion Gain versus Temperature 3 Measured at Pin3,terminated with 1.8kΩ and.1uf Mixer Conversion Gain Gmix(dB) Fmix=21.7MHz Ambient Temperature Ta( C) Ver

16 Output versus TemperatureMixer Output versus TemperatureMixer Output versus TemperatureIF Output versus TemperatureIF Condition Condition 2(Mixer 2(Mixer input) input) Condition Condition 1(IF 1(IF input) input) Output Voltage Vrssi(V) dBuVEMF 7dBuVEMF 6dBuVEMF 6dBuVEMF 5dBuVEMF 5dBuVEMF 4dBuVEMF 4dBuVEMF 3dBuVEMF 3dBuVEMF 2dBuVEMF 2dBuVEMF Ambient Temperature Ta( C) Output Voltage Vrssi(V) dBuVEMF 7dBuVEMF 6dBuVEMF 5dBuVEMF 4dBuVEMF.5.4 3dBuVEMF 2dBuVEMF Ambient Temperature Ta( C) [CAUTION] The specifications on this databook are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. 16 Ver.21839