CXA1741Q

CXA1741Q IF Amplifier for Analog Cellular Communications For the availability of this product, please contact the sales office. Description The CXA1741Q is an analog cellular(TACS/ NTACS) FM IF IC which incorporates an IF filter. Features • Incorporates 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. • The built-in filter permits mode changeover between TACS and NTACS. • 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). Applications Ideally suited for cellular phones, particularly handheld sets. Structure Bipolar silicon monolithic IC 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 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— E94245-TE CXA1741Q Block Diagram and Pin Configuration (Top View) MIXADJ1 MIXADJ2 MIXPS MIXIN IFPS GND 30 T4 31 29 28 27 26 25 24 VCC 23 22 IFIN T3 21 20 XTALIN PSN T5 32 PSN VCC1 33 MIXER RF AMP 19 XTALOUT GND 18 AGCPS 17 VREF 16 RSSIPS 15 T2 14 RSDETPS 13 T1 12 GND2 11 VCC2 10 GND1 34 BPF0 T6 35 1/2 OSC AGC FADJ1 36 FADJ2 37 BPF1 RSSI SGND 38 BIAS LIM DET BPFPS1 39 BPFPS2 40 1 SW(TACS/NTACS) 2 NC 3 BPFO 4 5 6 AUDIO 7 RSSI 8 GADJ(RSSI) 9 IF2 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— LIMPS CXA1741Q Pin No. 1 Symbol SW TACS NTACS Pin voltage DC AC 0V OPEN HIGH (3 V) I/O resistance 31 Equivalent circuit Description Changeover switch for built-in filter. TACS for Low; NTACS for High. ( ) 20µA 50k 1 50k VREF GND 34 2 3 4 5 NC BPFO 1.8 V Not internally connected. BPF output monitor. Not used normally. Connected to the LIM and RSSI inputs in the IC. 33 147 3 4 5 34 B.P.F N.F.B Network LIM RSSI 6 AUDIO 2.1 V 11 Outputs an AUDIO signal which is FM-detected. 1k 6 12 —3— CXA1741Q Pin No. 7 Symbol RSSI Pin voltage DC AC 1.2 V I/O resistance Equivalent circuit Description 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 (varies the resistance so as to obtain a linear RSSI output). 147 8 147 7 9 IF2 0.9 V 11 Limiter operation monitor. Not used normally. 147 9 12 10 LIMPS 1.8 V 11 Connects a limiter integrating capacitor. 10 12 —4— CXA1741Q Pin No. 11 Symbol VCC2 Pin voltage DC AC 3.0 V I/O resistance Equivalent circuit Description Power supply. Supplies current to the LIM, DET, and RSSI circuits. Ground. IC operation check. Connects an RSSI detector integrating capacitor. 12 13 14 GND2 T1 0V RSDETPS 1.4 V 11 147 14 12 15 16 T2 RSSIPS 1.8 V 11 IC operation check. Connects an RSSI integrating capacitor. 16 12 17 VREF 1.3 V 33 17 34 reference voltage used in the internal circuit 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. —5— CXA1741Q Pin No. 18 Symbol AGCPS Pin voltage DC AC 0.2 V I/O resistance Equivalent circuit Description Connects an AGC integrating capacitor. 33 18 VREF 34 15 19 XTALOUT 2.9 V 24 147 20 10k 15p 10k 19 20 XTALIN 2.9 V Connect a crystal oscillator to form a Colpitts-type oscillator circuit. When an external oscillator is used, its input must be connected to Pin 20. 25 21 21 22 GND IFIN 0V 1.3 V 24 23 IFPS 1.3 V 22 1.5k 1.5k 23 VREF 21 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. 24 VCC 3.0 V 25 GND 0V —6— CXA1741Q Pin No. 26 Symbol MIXIN Pin voltage DC AC 1.3 V I/O resistance Equivalent circuit Description RF AMP output monitor. Connected to the MIXER input in the IC. 27 27 MIXPS 1.3 V 26 MIXER RF AMP 28 MIX ADJ2 0.1 V Balance adjustment for mixers 1 and 2. 29 MIX ADJ1 0.1 V 4k 4k 28 29 4k 4k 660 660 30 31 32 33 T3 T4 T5 VCC1 IC operational check. 3.0 V 34 35 36 GND1 T6 FADJ1 0V Power supply. Supplies current to the PSN, BPF, and BIAS circuits. Ground. IC operational check. 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. 2.2 V 147 36 37 FADJ2 1.5 V 37 147 —7— CXA1741Q Pin No. 38 Symbol SGND Pin voltage DC AC 1.8 V I/O resistance Equivalent circuit 33 Description 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. 38 34 B.P.F signal reference voltage 39 BPFPS1 1.1 V 33 39 40 BPFPS2 1.2 V 40 34 reference voltage used for B.P.F 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. —8— CXA1741Q Electrical Characteristics 0dBm = 50Ω, 1mW VCC = 3V, Ta = 25°C FOSC = 89.9 MHz Conditions fin = 45 MHz, -30 dBm Pin 11 fin = 45 MHz, -30 dBm Pin 24 fin = 45 MHz, -30 dBm Pin 33 0V 3V Crystal osc. 89.9 MHz 1.2 1.6 1 1 Crystal osc. 89.9 MHz 70 Min. 0.8 2 3.8 -14 15 Typ. 1.1 2.9 5.3 -10 23 0.4 1.25 1.8 1.17 1.2 93 Max. 1.5 3.8 7 -7 30 0.6 1.3 2 1.4 1.4 130 Unit mA mA mA µA µA mA V V V V mV rms 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 Pin voltage - Pin 17 Pin voltage - Pin 38 Pin voltage - Pin 39 Pin voltage - Pin 40 OSC output swing Pin 19 IIL IIH I19 V17 V38 V39 V40 VOSC Wide BPF; TACS mode (Pin 1=Low) BPF output voltage - 1 BPF output voltage - 2 IF1 output voltage Mixer image rejection level BPF 6 dB bandwidth BPF 40 dB bandwidth BPF extraband attenuation FM detection level AM rejection ratio VTG1 VTG2 VTIF VIMAG BW6dB BW40dB ATT40K FMDET AMR fin = 45 MHz, -50 dBm fin = 45 MHz, -20 dBm fin = 45 MHz, -20 dBm fin = 44.9 MHz, -30 dBm Vin = -50 dBm, Swept with fin = 45 MHz regarded as the center Vin = -50 dBm, Swept with fin = 45 MHz regarded as the center fo ±40 kHz fin = 45 MHz, -30 dBm, fmod=1 kHz, Dev. = 5.6 kHz, Dev. = 5.6 kHz, used LPF 20 kHz fin = 45 MHz, -30 dBm, fmod = 1 kHz, Mod = 80% used LPF 20 kHz —9— 150 100 220 80 162 291 89 30 26 47 56 194 -27 250 -20 220 360 100 100 30 mV rms mV rms mV rms mV rms kHz kHz dB mV rms dB CXA1741Q Item Audio output distortion RSSI output voltage - 11 RSSI output voltage - 12 RSSI output voltage - 13 Symbol THD Conditions fin = 45 MHz, -30 dBm, fmod = 1 kHz, Dev. = 8 kHz, used LPF 20 kHz Min. Typ. 3.7 Max. 6 1.3 2.2 2.8 Unit % V V V RSSI11 No input RSSI12 fin = 45 MHz, -60 dBm RSSI13 fin = 45 MHz, -20 dBm 1 1.65 2.4 1.15 1.93 2.67 Narrow BPF; NTACS mode (Pin 1=High) Mixer 3rd inter-modulation BPF 6 dB bandwidth BPF 40 dB bandwidth BPF extraband attenuation FM detection level AM detection level Audio output distortion RSSI output voltage - 21 RSSI output voltage - 22 RSSI output voltage - 23 Others Equivalent input resistance Pin 22 Equivalent input capacitance Pin 22 BPF•fo temperature characteristics TACS mode BPF•fo temperature characteristics NTACS mode RIN CIN f = 55 MHz f = 55 MHz 1.4 4.7 kΩ pF IM3 BW6dB BW40dB f1 = 45.02 MHz, -30 dBm, f2 = 45.04 MHz, -30 dBm Vin = -50 dBm, Swept with fin = 45 MHz regarded as the center Vin = -50 dBm, Swept with fin = 45 MHz regarded as the center 4.5 13.5 23 62 99 16 2.8 1.09 1.91 2.65 20 16 mV rms kHz kHz dB mV rms dB % V V V ATT20K fo ±20 kHz FMNDET AMRN THDN fin = 45 Mhz, -30 dBm, fmod = 1 kHz, Dev. = 3 kHz, Used LPF 20 kHz fin = 45 Mhz, -30 dBm, fmod = 1 kHz, Mod = 80%, Used LPF 20 kHz fin = 45 Mhz, -30 dBm, fmod = 1 kHz, Dev. = 3 kHz, Used LPF 20 kHz RSSI21 No input RSSI22 f = 45 MHz, -60 dBm RSSI23 f = 45 MHz, -20 dBm Ta = -30 to + 70°C 1.5 kHz Ta = -30 to + 70°C 1.5 kHz —10— CXA1741Q Measurement Circuit 6 100 103 S6 500 10p 6p PSN 32 PSN 33 104 MIXER RF AMP 19 0.47µ 102 18 104 34 BPF0 35 1/ 2 AGC OSC 17 223 16 S4 56K 36 BPF1 37 VR10K 104 38 BIAS LIM 39 104 40 104 11 DET 12 13 RSSI 14 15 104 1k S3 5 1 S1 2 3 4 5 6 7 102 8 47k 9 S2 10 220k 1 2 3 4 —11— 1k 103 104 102 31 20 89.9MHz 30 29 28 27 26 25 24 23 101 22 1.5µ 104 Vcc 3V 7 10 S5 104 47 21 CXA1741Q Application Circuit 45MHz IN Oscillator circuit Vcc 7p 1.5µ 0.1µ 0.1µ 30 31 PSN 0.1µ 32 PSN Vcc 33 MIXER RF AMP 29 28 27 26 25 24 23 22 100p 10p 20 109.9MHz 21 0.33µ Vcc 19 18 0.047µ 34 BPF0 35 1/2 OSC 17 0.1µ 16 AGC 0.1µ 20k 36 BPF1 51k 37 RSSI 14 0.1µ 15 2.2µ 38 BIAS LIM DET 13 39 2.2µ 40 2.2µ 12 11 Vcc 0.1µ 1 2 3 4 5 94k 82p 6 7 220k 47k 8 9 10 0.1µ TACS 50K NTACS 50K AUDIO OUT Vcc 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. This makes IC other than TACS/NTACS standard possible to use without changing PCB pattern. 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— CXA1741Q 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 50 kHz. When a crystal resonator or like external 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 50 kHz signal, which is then fed to the limiter and RSSI circuit. 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. SW (Pin 1) can switch the NTACS and TACS modes. 45MHz IN IFIN 30 31 PSN 32 PSN 33 MIXER RF AMP 29 28 27 26 25 24 23 22 21 20 XTALIN Crystal Oscillator Circuit 19 XTALOUT 18 34 BPF0 35 1/2 OSC 17 16 AGC 36 BPF1 37 RSSI 15 14 38 BIAS LIM DET 13 39 12 40 11 1 2 3 4 5 6 7 RSSI OUT 8 9 10 TACS NTACS AUDIO OUT Vcc AUDIO RSSI output output Signal Flow —13— CXA1741Q 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 CXA1741Q oscillator. Vcc Vcc Vcc C2 20 20 600mVp-p or more Crystal 19 C1 L 19 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. (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 50 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— CXA1741Q 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. V Vcc (approx. 0.5V) Adjust for this curve. RSSI 7 8 RSSI 0 Input level dBm —15— CXA1741Q 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 affected 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 +8 kHz and –8 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 This circuit must be adjusted for the crystal oscillation frequency. Once the optimum value is obtained upon PCB conductive pattern determination, readjustment is unnecessary after sample changes. —16— CXA1741Q 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". Sensitivity of adjust R vs fo 60 55 BPF•fo [kHz] 50 45 52 54 56 58 60 62 64 66 68 70 72 Total resistance value [k Ω ] Pass Band Shift by the BPF•fo adjustment 20 19 NTACS•BW 20dB [kHz] 18 17 16 15 14 45 50 BPF•fo [kHz] 55 60 —17— CXA1741Q [dB] TACS 40 NTACS Response 30 20 CXA1741•SINAD TACS f=45MHz, FM Modulation Dev. 5.7kHz Audio 1kHz CCITT weighting NTACS f=45MHz, FM Modulation Dev. 3kHz Audio 1kH CCITT weighting Ta=25°C Vcc=3.3V 10 0 –120 –100 –80 –60 –40 –20 [dBm] Input level [dB] 0 S CXA1741•TACS CCITT weighting f=45MHz FM Modulation Dev. 5.7kHz Audio 1kHz Ta=25°C VCC=3.3V –10 –20 Response –30 –40 D –50 –60 –120 –100 –80 –60 –40 –20 N [dBm] Input level [dB] 0 S CXA1741•NTACS CCITT weighting f=45MHz FM Modulation Dev. 3kHz Audio 1kHz Ta=25°C VCC=3.3V –10 –20 Response –30 D –40 –50 N –60 –120 –100 –80 –60 –40 –20 [dBm] Input level —18— CXA1741Q Selectivity characteristics D/U [dB] 70 60 50 40 30 20 10 TACS NTACS VCC=2.7V Ta=25°C 20dB SINAD=–96dBm –50 –40 –30 –20 –10 +10 +20 +30 +40 +50 45MHz±∆f [kHz] Image rejection characteristics D/U [dB] 80 NTACS 70 VCC=2.7V Ta=25°C 60 50 40 30 20 10 TACS –40 –30 –20 –10 0 +10 +20 +30 +40 44.9MHz±∆f [kHz] Detuning characteristics Distortion [%] 14 12 NTACS 10 8 6 4 2 TACS TACS Deviation 5.7kHz Audio 1kHz CCITT weighting NTACS Deviation 3kHz Audio 1kHz CCITT weighting VCC=2.7V Ta=25°C –10 –8 –6 –4 –2 0 +2 +4 +6 +8 +10 45MHz±∆f [kHz] —19— CXA1741Q RSSI characteristics-1 [V] 3.0 TACS VCC=2.7V 2.5 [V] 3.0 NTACS VCC=2.7V 2.5 RSSI characteristics-2 70°C 25°C –30°C 70°C 25°C –30°C RSSI output voltage 2.0 RSSI output voltage Signal input from Pin 22 (IF IN) Voltage measurement at Pin 7 –100 –50 IF input voltage Modulation characteristics 0 dBm 2.0 1.5 1.5 1.0 1.0 0.5 0.5 0 0 –100 –50 IF input voltage 0 dBm Distortion [dB] –20 IFIN to Audio OUT f=4.5Mhz, –40dBm Audio=1kHz CCITT weighting VCC=3.3V Ta=25°C NTACS –30 BPF output [dBV] 0 IFIN to BPF OUT F0=45MHz F1=45.02MHz F2=45.04MHz –20 Ta=25°C VCC=3.3V TACS I/O characteristics IM3 –40 –40 –60 –50 2 4 6 Deviation [kHz] 8 10 –80 –100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0 IF input [dB] Audio frequency response Response [dB] +2 0 –2 –4 –6 –8 –10 –12 –14 10 100 1k Frequency [Hz] 10k 100k 0dB normalized at 1kHz TACS deviation 5.7kHz NTACS deviation 3kHz IFIN 45MHz, –40dBm Ta=25°C, VCC=3.3V NTACS TACS —20— CXA1741Q Package Outline Unit : mm 40PIN QFP (PLASTIC) 9.0 ± 0.4 + 0.4 7.0 – 0.1 30 21 + 0.35 1.5 – 0.15 + 0.1 0.127 – 0.05 0.1 31 20 A 40 11 1 0.65 + 0.15 0.1 – 0.1 + 0.15 0.3 – 0.1 10 ± 0.12 M 0.5 ± 0.2 (8.0) PACKAGE STRUCTURE PACKAGE MATERIAL LEAD TREATMENT LEAD MATERIAL PACKAGE WEIGHT EPOXY RESIN SOLDER / PALLADIUM PLATING COPPER / 42 ALLOY 0.2g DETAIL A SONY CODE EIAJ CODE JEDEC CODE QFP-40P-L01 ∗QFP040-P-0707 —21—