CXA1742Q IF Amplifier for Analog Cellular Communications For the availability of this product, please contact the sales office. Description The CXA1742Q is an analog cellular(AMPS) FM IF IC which include an IF filter. Features • Include a ceramic filter function, which is normally mounted externally. • Quadrature detection discriminator function. • This IC has almost all IF functions and is ideal for reduction in set size because of few external parts required. • Channel filter conforming to the AMPS standard. • Wide operating voltage range (2.7 V to 3.6 V) and low current consumption (Icc=10 mA (typ.) when Vcc= 3 V). • Wide range and excellent temperature characteristics for the RSSI (receiving signal strength indicator). 40 pin QFP (Plastic) Absolute Maximum Ratings (Ta = 25°C) • Supply voltage VCC 5 V • Operating temperature Topr –35 to +85 °C • Storage temperature Tstg –65 to +150 °C • Allowable power dissipation PD 500 mW Operating Conditions Supply voltage VCC 2.7 to 3.6 V Applications Ideally suited for cellular phones, particularly handheld sets. Structure Bipolar silicon monolithic IC Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. —1— E95119-TE CXA1742Q Block Diagram and Pin Configuration T3 MIXADJ1 MIXADJ2 MIXPS MIXIN GND VCC IFPS IFIN GND (Top View) 30 29 28 27 26 25 24 23 22 21 20 XTALIN T4 31 RF AMP PSN 19 XTALOUT T5 32 PSN MIXER VCC1 33 GND1 34 18 AGCPS 1/ 2 BPF0 17 VREF OSC T6 35 16 RSSIPS AGC FADJ1 36 15 T2 BPF1 FADJ2 37 14 RSDETPS RSSI SGND 38 13 T1 BIAS LIM DET 6 7 8 9 10 LIMPS 5 IF2 4 GADJ(RSSI) 3 RSSI 2 AUDIO 1 LIMIN 11 VCC2 BPFO BPFPS2 40 NC 12 GND2 SW BPFPS1 39 Note) Pins 21 and 25 are connected via the IC internal wiring. Pins 12, 21 and Pins 25, 34 are connected via IC internal resistors. When designing a PCB, ensure that all GND pins of IC are connected to the GND on PCB with its connection wiring distance minimized. —2— CXA1742Q Pin No. Symbol 1 SW Pin voltage DC AC I/O resistance Equivalent circuit Description Used at the GND potential. 31 20µA 50k 1 50k VREF 34 2 3 NC BPFO GND Not intemally connected. BPF output. Connect to Pins 4,5. 1.83V 33 147 3 34 B.P.F N.F.B Network 4 5 LIMIN Open Base LIM 4 147 5 Input of BPF output. The DC bias is applied from pin3 when the output of BPF is connected to them. RSSI 6 AUDIO 1.85V 11 1k 6 12 —3— Outputs an AUDIO signal which is FM-detected. CXA1742Q Pin No. Symbol 7 RSSI Pin voltage DC AC I/O resistance Equivalent circuit Description 1.1 V RSSI output. Outputs a DC voltage in accordance with the signal input to the RF amplifier. 11 147 7 12 8 GADJ 0.2 V Adjusts the RSSI amplifier gain. 8 147 9 IF2 7 147 1.07 V Limiter operation monitor. Not used normally. 11 147 9 12 10 LIMPS 1.82 V 11 10 12 —4— Connects a limiter integrating capacitor. CXA1742Q Pin voltage DC AC Pin No. Symbol 11 VCC2 3.0 V 12 13 GND2 T1 0V 14 I/O resistance Equivalent circuit Description Power supply. Supplies current to the LIM, DET, and RSSI circuits. Ground. IC operation check. RSDETPS 1.35 V 11 Connects an RSSI detector integrating capacitor. 147 14 12 15 T2 16 RSSIPS IC operation check. 1.83 V 11 Connects an RSSI integrating capacitor. 16 12 17 VREF 1.25 V 33 17 34 reference voltage used in the internal circuit —5— Monitor for the reference voltage used in the internal circuit. When connected to an external capacitor, this pin also functions to lower the reference voltage dynamic impedance. CXA1742Q Pin No. 18 Symbol Pin voltage DC AC I/O resistance Equivalent circuit AGCPS 0.233 V Description 33 Connects an AGC integrating capacitor. 18 VREF 34 15 19 XTALOUT 24 147 20 10k 15p 10k 19 20 XTALIN 2.96 V 25 21 22 GND IFIN 21 0V 1.25 V 24 23 IFPS 1.25 V 22 23 1.5k 1.5k VREF 21 24 VCC 3.0 V 25 GND 0V Connect a crystal oscillator to form a Colpitts-type oscillator circuit. When an external oscillator is used, its signal must be connected to Pin 20. 25 Ground. RF amplifier input. The relationship between IFIN (Pin 22) and IFPS (Pin 23) is designed so that the IC internal stray capacitance is small. Therefore, if Pins 22 and 23 are used for balance input, the common-mode rejection deteriorates. Power supply. Supplies current to the RF AMP, MIXER, OSC, and 1/2 DIVIDER circuits. Ground. —6— CXA1742Q Pin No. Symbol 26 MIXIN Pin voltage DC AC I/O resistance Equivalent circuit Description 1.3 V RF AMP output monitor. Connected to the MIXER input in the IC. 27 27 MIXPS 1.3 V 26 MIXER 28 MIX ADJ2 0.143 V 29 MIX ADJ1 0.143 V RF AMP Balance adjustment for mixers 1 and 2. 4k 4k 4k 4k 28 29 660 30 31 32 33 T3 T4 T5 VCC1 34 35 GND1 T6 0V 36 FADJ1 2.29 V 660 IC operational check. 3.0 V Power supply. Supplies current to the PSN, BPF, and BIAS circuits. Ground. IC operational check. 147 36 37 FADJ2 37 1.55 V 147 —7— When the resistance value of an external resistor connected between Pins 36 and 37 is varied, the center frequency of the BPF in the IC changes accordingly. CXA1742Q Pin No. Symbol 38 SGND Pin voltage DC AC I/O resistance Equivalent circuit 1.83 V Description 33 38 34 Monitor for the pseudground voltage used in the internal circuits. When connected to an external capacitor, this pin also functions to lower the reference voltage dynamic impedance. B.P.F signal reference voltage 39 BPFPS1 1.17 V 33 39 40 BPFPS2 1.2 V 40 34 reference voltage used for B.P.F —8— Monitor for the reference voltage used by the BPF. When connected to an external capacitor, these pins also function to lower the reference voltage dynamic impedance. CXA1742Q Electrical Characteristics Item Symbol Current consumption - 1 ICC-11 Current consumption - 2 ICC-24 Current consumption - 3 ICC-33 Pin current Pin 1 - Low Pin current Pin 1 - High Pin current Pin 19 0dBm = 50Ω, 1mW VCC = 3V, Ta = 25°C FOSC = 89.88 MHz Conditions fin = 45 MHz, –30 dBm Pin 11 fin = 45 MHz, –30 dBm Pin 24 fin = 45 MHz, –30 dBm Pin 33 Min. Typ. Max. Unit 0.8 1.1 1.5 mA 2 2.8 3.7 mA 3.6 5.1 6.7 mA IIL 0V –14 –10 –7 µA IIH 3V 15 22 30 µA I19 Crystal osc. 89.88 MHz 0.4 0.6 mA Pin voltage - Pin 17 V17 1.2 1.25 1.3 V Pin voltage - Pin 38 V38 1.7 1.83 1.95 V Pin voltage - Pin 39 V39 1.05 1.17 1.3 V Pin voltage - Pin 40 V40 1.07 1.2 1.33 V OSC output swing Pin 19 VOSC Crystal osc. 89.88 MHz 70 93 130 mV rms 220 AMPS mode (Pin 1=Low) BPF output voltage - 1 VTG1 fin = 45 MHz, –50 dBm 90 152 BPF output voltage - 2 VTG2 fin = 45 MHz, –20 dBm 200 260 IF1 output voltage VTIF fin = 45 MHz, –20 dBm 70 100 130 Mixer image rejection level VIMAG fin = 44.88 MHz, –30 dBm 30 100 BPF 6 dB bandwidth BW6dB 32 35 BPF 40 dB bandwidth BW40dB BPF extraband attenuation ATT40K FM detection level FMDET AM rejection ratio AMR Vin = –50 dBm, Swept with fin = 45 MHz regarded as the center Vin = –50 dBm, Swept with fin = 45 MHz regarded as the center 29 fo ±40 kHz fin = 45 MHz, –30 dBm, fmod=1 kHz, Dev. = 8 kHz, used LPF 20 kHz fin = 45 MHz, –30 dBm, fmod = 1 kHz, Mod = 80% used LPF 20 kHz —9— mV rms mV rms mV rms mV rms kHz 47 kHz 56 dB 130 166 23 30 200 mV rms dB CXA1742Q Item Audio output distortion Symbol THD Conditions Min. Typ. Max. Unit 3.2 5.5 % 1 1.1 1.25 V fin = 45 MHz, –30 dBm, fmod = 1 kHz, Dev. = 8 kHz, used LPF 20 kHz RSSI output voltage - 11 RSSI11 No input RSSI output voltage - 12 RSSI12 fin = 45 MHz, –60 dBm 1.65 1.88 2.1 V RSSI output voltage - 13 RSSI13 fin = 45 MHz, –20 dBm 2.4 2.62 2.8 V Others Equivalent input RIN resistance Pin 22 Equivalent input CIN capacitance Pin 22 BPF•fo temperature characteristics AMPS mode f = 45 MHz 1.4 kΩ f = 45 MHz 4.7 pF Ta = –30 to + 70°C 1.5 kHz —10— CXA1742Q Measurement Circuit 6 10 104 S6 101 1.5µ 103 47 S5 104 100 500 28 27 26 25 24 23 22 21 20 31 RF AMP PSN 102 29 89.88MHz 10p 30 6p 19 32 0.47µ PSN 102 MIXER 33 18 104 104 34 1/2 17 OSC BPF0 223 35 16 AGC 56K 15 36 S4 BPF1 37 14 RSSI VR10K 104 1k 104 38 13 BIAS S3 LIM 5 DET 39 12 40 11 104 4 5 6 7 8 9 102 47k 220k 1 2 —11— 3 10 4 103 3 S2 2 1k 1 104 104 S1 Vcc 3V 7 CXA1742Q Application Circuit Oscillator circuit 45MHz IN Vcc 10p 1.5µ 100p 0.1µ 0.1µ 30 29 28 27 26 25 24 23 22 89.88MHz 21 RF AMP PSN Vcc 19 32 PSN MIXER 33 Vcc 0.47µ 20 31 0.1µ 6p 34 18 1/2 17 OSC 0.1µ 0.1µ BPF0 35 16 AGC 0.1µ 20k 15 36 BPF1 51k 37 2.2µ 14 RSSI 38 0.1µ 13 BIAS LIM DET 39 12 40 11 2.2µ Vcc 2.2µ 1 2 3 4 5 6 7 8 9 10 0.1µ 94k 220k 82p AUDIO OUT 0.1µ 47k RSSI OUT Note) Use a 0.1µF capacitor for Pin 14 decoupling. The IC malfunctions at a capacitance of 0.047µF or lower. The oscillator circuit must be changed according to the crystal characteristics. When designing PCB pattern, make PCB pattern so that Pins 3, 4, and 5 are connected correlatively. Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same. —12— CXA1742Q Description of Operation A 45 MHz IF signal is input to Pin 22. This input signal is amplified at the RF AMP and then mixed with the local oscillation signals from the oscillator at the mixer to change the signal frequency to 60 kHz. When a crystal or the other resonator circuit is connected to Pins 19 and 20, the oscillator can be self-executed by composing a Colpitts-type oscillation circuit. It can be also used with an external local oscillation signal applied to Pin 20. The internal BPF eliminates any interference from the converted 60 kHz signal, which is then output to Pin 3. The resulting signal is fed to Pins 4 and 5 to connect to the limiter and RSSI circuits. The limiter eliminates an amplitude component from the signal. The resulting signal is then detected at the quadrature FM detector circuit, and Pin 6 outputs an audio signal. The RSSI circuit detects the RF AMP input signal voltage and generates from Pin 7 the DC voltage where the detected voltage value is logarithmically compressed. The resulting signal is fed to Pins 4 and 5 to connect to the limiter and RSSI circuits. 45MHz IN IFIN 30 29 28 27 26 25 24 23 22 21 20 31 RF AMP PSN 19 32 PSN MIXER 33 34 18 1/2 17 OSC BPF0 35 16 AGC 15 36 BPF1 37 14 RSSI 38 13 BIAS LIM DET 39 12 40 11 1 2 3 4 5 6 AUDIO OUT 7 8 RSSI OUT AUDIO RSSI output output Signal Flow —13— 9 10 XTALIN XTALOUT Crystal Oscillator Circuit CXA1742Q 1) Power supply Power supply pins (Pins 11, 24, and 33) must be decoupled with the shortest distance. 2) Oscillator The figures below show how to use the CXA1742Q oscillator. VCC VCC SG 102 C2 20 20 L 19 Crystal VCC 19 C C1 L VCC (a) Inputting a local oscillation signal from an external circuit. The circuit current varies with the externally fed signal amplitude. The reason is that the AGC circuit, which works to maintain the oscillation amplitude constant when a Colpitts-type oscillator circuit is formed, also operates when an external local oscillation signal is input. Tune the L and C to the Pin 20 input signal frequency or the needed frequency. The tuning point is decided at the minimum of the Pin 19 current. Do not decide the point when the probe is connected to Pin 19 because the tuned frequency is deviated by the stray capacitor of the probe. (b) Configuring a Colpitts-type oscillator circuit. The C1, C2, and L must be changed according to the crystal characteristics. The oscillation Tr in the IC is internally subjected to AGC so that the oscillation level at Pin 19 is not likely to be affected by temperature or supply voltage fluctuations. 3) Mixers Since the BPF in the IC has an fo value as low as 60 kHz, the IC employs an image rejection type of mixer having an enhanced interference elimination capability. Therefore, the two internal mixers must be accurately adjusted so that their gains are equal. Normally, an adequate degree of image rejection is provided without using Pins 28 and 29. However, when they are used for adjustment purposes, an increased degree of image rejection will result. 500Ω 29 28 —14— CXA1742Q 4) BPF The passband frequency of the built-in filter should be adjusted. For adjustment method, adjust skirt characteristics of band-pass filter to be symmetric with respect to the center frequency. Or observe the AUDIO output at Pin 7 and adjust the variable resistor between Pins 36 and 37 so as to minimize the AUDIO output distortion. 36 37 5) RSSI (receiving signal strength indicator) RSSI detects the input signal level. The IC generates a DC voltage output, which is nearly proportional to the logarithmic value of RF input level. The output level can be varied by adjusting GADJ (Pin 8) resistance value. Adjust the resistance value so that saturation does not occur when the input level is high. VCC (approx. 0.5V) Adjust for this curve. RSSI V 7 RSSI 0 Input level dBm —15— 8 CXA1742Q Notes on Operation 1. This IC must be handled with care because it is extremely susceptible to electrostatic surges. Particularly, IFIN (Pin 22) is easily damaged by electrostatic surges. 2. When the 0.1µF capacitor connected to Pin 14 has a capacitance of 0.047µF or less, the IC malfunctions. Be sure that the employed capacitor has an excellent temperature characteristics. 3. When the capacitance value of the 0.1µF capacitor connected to Pin 38 is decreased, the IC characteristics begin to slightly deteriorate. Further, a capacitance value increase would not improve the IC characteristics accordingly. 4. When the capacitance value of the 0.1µF capacitor connected to Pin 40 is decreased, the IC characteristics slightly deteriorate. 5. Vcc1 (Pin 33) supplies the power to the reference bias voltage generator circuit which is necessary for IC operations. If the same VCC power supply is not provided for Vcc voltages to be applied to Pins 11, 19, 24, and 33, ensure that the Pin 33 Vcc rises first. 6. Be sure that nothing is connected to Pins 13, 15, 30, 31, 32, and 35. 7. Resistance between Pins 36 and 37 The signal of 45 MHz, –50 dBm is input from Pin 22 (IFIN) and the level of Pin 3 (BPFOUT) is read. After that when this frequency is varied to +18 kHz and –18 kHz respectively, resistance value between Pins 36 and 37 is varied to be the same attenuation level. 8. Inductance between Pins 26 and 27 Adjustment must be made so that a 45 MHz parallel resonance circuit is formed by the inductor between Pins 26 and 27 and the IC stray capacitor. This adjustment assures that an increased mixer conversion gain is provided at a low input signal level. Once the optimum value is obtained upon PCB conductive pattern determination, readjustment is unnecessary after sample changes. 9. Pin 19 resonance circuit Tune this circuit to the crystal oscillation frequency for normal use, tune to the external SG signal frequency when a signal is input from the external SG. Once the optimum value is obtained upon PCB conductive pattern determination, readjustment is unnecessary after sample changes. —16— CXA1742Q Example of Representative Characteristics The following characteristic curves are measured after IC adjustment. If the IC is not properly adjusted, the resulting characteristics are not close to the representative characteristics presented below. When making measurements, observe precautions 7, 8, and 9 under "Notes on Operation". CXA1742Q.SINAD AMPS 35 –10 25 f=45MHz Dev. 8kHz Audio 1kHz Cmessage weighting Ta=25°C VCC=3V 15 10 5 0 –120 –100 –80 –60 –40 –20 Response SINAD 30 20 AAA AA AAAA AAA AA AA AA AAAA AAA A A AA AAAA AAAAAA AA CXA1742Q. AMPS (dB) 0 (dB) 40 –30 –40 –50 N –60 –140 –20 (dBm) Input level S f=45MHz Dev. 8kHz Audio 1kHz Cmessage weighting Ta=25°C VCC=3V D –120 –100 –80 –60 —40 –20 Input level Selectivity characteristics 0 (dBm) Image rejection characteristics (dB) 80 (dB) 70 60 70 50 60 D/U D/U 40 30 20 50 40 10 VCC=3V Ta=25°C 12dB SINAD=–96.1dBm 0 –10 –80 –60 –40 30 –20 0 20 45MHz ±∆f 40 60 VCC=3 V Ta=25°C 20 –60 80 (kHz) –40 –20 Detuning characteristics 60 80 (kHz) 14 16 (kHz) (%) 5 VCC=2.7V Ta=25°C 5 4 3 2 –15 VCC=2.7V Ta=25°C 4 Distortion Distortion 40 Modulation characteristics (%) 7 6 0 20 44.88MHz ±∆f 3 2 1 –10 –5 0 45MHz ±∆f 5 10 15 0 (kHz) —17— 0 2 4 6 8 10 Deviation 12 CXA1742Q RSSI characteristics (v) 3 Audio output Frequency characteristics 75°C 25°C –30°C (dB) 0 2.5 Responce –4 RSSI voltage 2 1.5 –8 VCC=3V, Ta=25°C INPUT f=45MHz, –50dBm Dev=8kHz –12 –16 1 0 10 Frequency 0.5 20 (kHz) VCC=3 V –100 0 (dBm) –50 Input voltage Band-pass filter characteristics The response characteristics of the band-pass filter (total value of BPF0 and BPF1) are shown below. Supply voltage Vcc = 3 V, operating temperature Ta = 25°C I/O characteristics (dBV) 0 BPF output –20 70°C VCC=3 V 25°C IN PUT:pin 22 –30°C f=45MHz MEASUREMENT:pin 3 AGC operating range –40 –60 –80 –100 –80 –60 IF input –40 –20 0 (dBm) BPF characteristics-1 BPF characteristics-2 (dB) (µs) 250 (dB) 10 (µs) 125 0 –20 –20 G.DELAY 125 GAIN GAIN –10 G.DELAY 0 –40 –30 –60 0 –40 40 50 60 Frequency 70 80 (kHz) –80 20 —18— 40 60 Frequency 80 0 100 (kHz) CXA1742Q Unit : mm 40PIN QFP (PLASTIC) + 0.35 1.5 – 0.15 + 0.1 0.127 – 0.05 9.0 ± 0.4 + 0.4 7.0 – 0.1 0.1 21 30 20 31 A 11 40 1 + 0.15 0.3 – 0.1 0.65 10 ± 0.12 M (8.0) + 0.15 0.1 – 0.1 0.5 ± 0.2 Package Outline DETAIL A PACKAGE STRUCTURE PACKAGE MATERIAL EPOXY RESIN SONY CODE QFP-40P-L01 LEAD TREATMENT SOLDER / PALLADIUM PLATING EIAJ CODE ∗QFP040-P-0707 LEAD MATERIAL COPPER / 42 ALLOY PACKAGE WEIGHT 0.2g JEDEC CODE —19—