CXA3176N IF Amplifier for FM Receiver (AFC Supported) Description The CXA3176N is a low current consumption FM IF amplifier which employs the newest bipolar process. It is suitable for FM receiver using AFC. 24 pin SSOP (Plastic) Features • Low current consumption : 0.95 mA (typ. at VCC1=1.4 V) 0.15 mA (typ. at VCC2=3.0 V) • Small package 24-pin SSOP • Second mixer and oscillator • Needless of IF decoupling capacitor • Reference power supply for operational amplifier • RSSI function (dynamic range of 70 dB) • IF input, VCC standard • AFC function • Maximum input frequency : 30 MHz Absolute Maximum Ratings • Supply voltage VCC • Operating temperature Topr • Storage temperature Tstg • Allowable power dissipation PD Operating Condition Supply voltage Applications • FM receiver supporting AFC • Double conversion FM receiver VCC1 VCC2 7.0 –20 to +75 –65 to +150 417 V °C °C mW 1.1 to 4.0 2.5 to 4.0 V V Structure Bipolar silicon monolithic IC MIX IN GND REG OUT REG CONT LVA OUT VCC2 CHARGE B.S. AUDIO NC AMP_OUT RSSI Block Diagram and Pin Configuration 24 23 22 21 20 19 18 17 16 15 14 13 22dB LVA GND REG RSSI AFC MIX OSC QUAD_DET IF_LIM FILTER 2 3 4 5 6 7 8 9 10 11 12 OSC IN OSC OUT MIX OUT VCC1 IF IN AFC AFC_C QUAD C1 C2 C3 RSSI_C ×4 1 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— E96X14A8Z CXA3176N Pin Description Pin No. 1 Symbol OSC IN Pin voltage Equivalent circuit VCC 300 15k 1.4 V Description Connects the external parts of crystal oscillator circuit. A capacitor and crystal oscillator are connected to these pins and VCC. 1 72 15k 2 2 OSC OUT 0.7 V GND VCC 1.5k Mixer output. Connect a 450 kHz ceramic filter between this pin and IF IN. 3 3 MIX OUT 1.3 V GND 4 VCC1 Power supply 1. 1.5k 20k 5 IF IN 20k VCC 1.5k 5 1.4 V IF limiter amplifier input. GND 6 AFC — AFC output. VCC 6 7 GND 7 AFC_C — —2— Connects the capacitor that becomes the AFC time constant. CXA3176N Pin No. Symbol Pin voltage Equivalent circuit Description VCC 20k 8 QUAD 1.4 V 22k Connects the phase shifter of FM detector circuit. 8 20p GND VCC 9 10 11 C1 C2 C3 0.2 V Connects the capacitor that determines the LPF cut-off. 9 35k 10 11 12 RSSI_C GND 0.1 V VCC Connects the capacitor that determines the RSSI rising characteristics. 12 13 GND 13 RSSI RSSI circuit output. 0.1 V VCC 14 AMP OUT VCC2/2 Output for the detector output amplification circuit. 14 GND 15 NC — Not connected. VCC 16 AUDIO 0.2 V Input for the detector output amplification circuit and AFC circuit. The filter circuit output is connected. 16 GND —3— CXA3176N Pin No. Symbol Pin voltage Equivalent circuit Description 17 Controls the battery saving. Setting this pin low suspends the operation of IC. (Applied voltage range : –0.5 V to +7.0 V) 72 20k 17 B.S. — 140k GND 20k 18 18 CHARGE — 100k GND 19 VCC2 — Power supply 2. 20 72 20 LVA OUT Controls the time constant of the AFC circuit. Set this pin high to make the short time constant. (Applied voltage range: –0.5 V to +7.0 V) — GND LVA comparator output. It is open collectors. (Applied voltage range: –0.5 V to +7.0 V) VCC 21 REG CONT Output for internal constant-voltage source amplifier. Connect the base of PNP transistor. (Current capacity : 100 µA) 72 — 21 GND VCC 22 REG OUT 1.0 V Constant-voltage source output. Controlled to maintain 1.0 V. 78k 22 1k 22k GND 23 GND — Ground VCC 2k 4.16k 4.16k 24 MIX IN 1.4 V Mixer input. 24 GND —4— CXA3176N Electrical Characteristics (VCC1=1.4 V, VCC2=3 V, Ta=25 °C, FS=21.7 MHz, FMOD=4 kHz, FDEV=4.5 kHz, AMMOD=30 %) Item Current consumption1 Current consumption2 Current consumption AM rejection ratio VB output current VB output saturation voltage REG OUT voltage Symbol ICC1 ICC2 ICCS AMRR IOUT VSATVB VREG LVA operating voltage VLVA LVA output leak current LVA output saturation voltage Logic input voltage high level Logic input voltage low level ILLVA VSATLVA VTHBSV VTLBSV Limiting sensitivity VIN (LIM) RSSI output offset Mixer input resistance Mixer output resistance IF limiter input resistance AMP OUT VORSSI RINLIM ROUTMIX RINLIM VAMP Conditions Measurement circuit 1, Measurement circuit 1, Measurement circuit 1, Measurement circuit 2, Measurement circuit 3 Measurement circuit 3 Output current 0 µA Measurement circuit 4, V1=1.4 to 1.0 V Measurement circuit 4, Measurement circuit 5 — — Measurement circuit 2, Data filter fc=6.2 kHz Measurement circuit 6 — — — Measurement circuit 2 —5— V2=1.0 V V2=1.0 V V2=0 V 30 k LPF V1=1.0 V Min. 0.5 — — 25 100 — 0.92 Typ. 0.95 0.15 6 — — — 0.97 Max 1.35 0.25 10 — — 0.4 1.02 Unit mA mA µA dB µA V V 1.00 1.05 1.10 V — — 0.9 — — — — — 2.0 0.4 — 0.35 µA V V V — –108 — dBm — 1.6 1.2 1.2 500 150 2.0 1.5 1.5 630 300 2.4 1.8 1.8 800 mV kΩ kΩ kΩ mVrms CXA3176N Electrical Characteristics Measurement Circuit Vin V3 3.0V 10p to 120p A 23 1 22 2 21 3 20 4 5 19 18 6 7 17 8 16 9 15 10 14 11 V2 1.0V 13 24 23 22 21 20 19 18 17 16 15 14 13 1 2 3 4 5 6 7 8 9 10 11 12 12 VCC 22p A V V4 15p V1 1.4V 1µ VCC V1 1.4V Measurement circuit 1 100µA V3 3V V 100k 23 22 21 20 19 18 17 16 15 14 13 1 2 3 4 5 6 7 8 9 10 11 12 V2 1.0V 24 23 22 21 20 19 18 17 16 15 14 13 1 2 3 4 5 6 7 8 9 10 11 12 V1 1.4 to 1.0V VCC V1 1.4V Measurement circuit 4 Measurement circuit 3 50µA V3 3V V 1 23 2 22 3 21 4 20 5 19 6 18 7 V3 3V V2 1.0V 17 8 16 9 15 10 14 11 V1 1.4V V2 1.0V V 24 23 22 21 20 19 18 17 16 15 14 13 1 2 3 4 5 6 7 8 9 10 11 12 13 12 VCC VCC 1200p Measurement circuit 2 V3 3V V V2 1.0V 24 VCC GND 5.6k GND A V3 0.5V 24 V 1000p 1200p 1200p 24 V3 3.0V 1.8µ V2 Measurement circuit 5 —6— V1 1.4V 100p Measurement circuit 6 VCC P1 L1 GND 1.8µH C3 XTAL 1 24 OSC 1000P C4 22P C6 GND 2 MIX 23 GND GND 15P 10P to 120P GND 3 22 10µ REG P7 C5 4 REG 100k 5 LVA 20 VB_REG 21 C9 6 IF_LIM 19 ×4 AFC 10µ LVA P6 0.01µ 10µ C7 R4 CERAFIL C8 GND 7 18 GND 0.01µ GND 8 BS 16 15 22dB GND 9 10 FILTER AUDIO QUAD_DET 17 GND 11 RSSI 14 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. RF SMA PNP 5.6K C2 P2 AFC 470P GND DISK S2 C11 GND 12 13 VCC2 P5 C12 470P C10 R5 1µ AMP_OUT P4 S1 RSSI P3 C13 470P —7— C14 100P Application Circuit CXA3176N C15 CXA3176N Application Notes 1) Power Supply The CXA3176N, with built-in regulator, is designed to permit stable operation at a wide range of supply voltage of VCC1=1.1 to 4.0 V and VCC2=2.5 to 4.0 V. Decouple the wiring to VCC (Pins 4 and 19) as close to the pin as possible. 2) Oscillator Input Oscillator input method a) Using Pins 1 and 2, input a self-excited oscillation signal through the composition of a Colpitts type crystal oscillator circuit. b) Directly input a local oscillation signal to Pin 1. 1 1 2 2 3 3 Ceramic filter VCC Ceramic filter From local signal Fig. 1 3) Mixer The mixer is of double-balance type. Pin 24 is the input pin. Input though a suitable matching circuit. The input impedance is 2.0 kΩ. Pin 3 serves as the output pin for the mixer, and a load resistance of 1.5 kΩ is incorporated. 4) IF Filter The filter to be connected between this mixer output and the IF limiter amplifier input should have the following specifications. I/O impedance : 1.5 kΩ ±10 % Band width : Changes according to applications. 5) IF Limiter Amplifier The gain of this IF limiter amplifier is approximately 100 dB. Take notice of the following points in making connection to the IF limiter amplifier input pin (Pin 5). a) Wiring to the IF limiter amplifier input (Pin 5) should be as short as possible. b) As the IF limiter amplifier output appears at QUAD (Pin 8), wiring to the ceramic discriminator connected to QUAD should be as short as possible to reduce the interference with the mixer output and IF limiter amplifier input. 3 4 5 6 7 8 VCC Wire as short and apart as possible Fig. 2 —8— As short as possible 9 CXA3176N 6) Quick Charge In order to hasten the rise time of Pin 7 from when power is turned on, the CXA3176N features a quick charge circuit. The capacitance value connected to Pin 7 should be chosen such that the voltage does not vary much due to discharge during battery saving. Connect a signal for controlling the quick charge circuit to Pin 18. Setting this pin high enables the quick charge mode, and setting this pin low enables the steady-state reception mode. Quick charge is used when the power supply is turned on. The battery saving must be set high at the time. Connect Pin 18 to GND when quick charge is not being used. Timing Power supply (Pin 4) Quick charge (Pin 18) H Battery saving (Pin 17) H 5ms 1ms 1ms L L battery saving active Fig. 3 7) Detector The detector is of quadrature type. To perform phase shift, connect a ceramic discriminator to Pin 8. The phase shifting capacitor for the quadrature detector is incorporated. The FM signal demodulated with the detector will be output to AMP_OUT (Pin 14) through the internal LPF. The CDBC450CX50 (MURATA MFG. CO., LTD.) ceramic discriminator is recommended for the CXA3176N. 7 8 9 5.6k Ceramic discriminator CDBC450CX50 VCC Fig. 4 —9— CXA3176N 8) REG CONT Controls the base bias of the external transistors. 9) LVA OUT This pin goes high (open) when the supply voltage becomes lower. Since the output is an open collector, it can be used to directly drive the CMOS device. The setting voltage of the LVA is 1.05 V (typ.), and it possesses a hysteresis with respect to the supply voltage. The hysteresis width is 50 mV (typ.). 10) B.S. Operation of the CXA3176N can be halted by setting this pin low. This pin can be connected directly to the CMOS device. The current consumption for battery saving is 10 µA or less (at 1.4 V). B.S. 17 Fig. 5 11) Control Pins The function controls are as shown below. Pin No. 17 Symbol B.S. Battery saving Function mode control Input high IC operation∗ Input low Sleep 18 CHARGE Pin 7 charge speed control Quick charge Slow charge∗ Note) When each function is not controlled externally, set it to the state with an asterisk (∗). 12) LPF Constant The composition of the data filter is ternary. The first-stage cut-off fC1 is fC1 = 1 2πC12R The second-stage cut-off fC2 is fC2 = 1 2πR√C13 C14 C12, C13, C14 : R : , Q = C13 C14 External capacitance shown in the Application Circuit IC internal resistance The Butterworse characteristic is for C12=C13=C14. R is approximately 55 kΩ ±20 %. —10— CXA3176N 13) AFC The AFC is of the current output type which outputs the frequency deviation in the form of the current and converts it to the voltage. The output current range is approximately ±0.4 µA for the slow mode and ±70 µA for the fast mode. External parts BUF Vin (S curve voltage) V=it/C LPF Vref 1st OSC for 1st MIX for FM receiver FM receiver 7 ×4 6 To CXA3176N VCO C Vref Vref Vout (AFC voltage) RF CXA3176N AFC Principle Diagram The Pin 7 voltage V continues to change till the Vin value reaches the Vref value. When these values are equal, the Pin 7 output current becomes “0” and the voltage is determined by the charge and time. The Pin 7 voltage V is output to Pin 6 through the amplifier. Vout=Vref+4 (V–Vref) The Vout operating range is 0.4 V to 4 (VCC–0.2) V so that AFC should be set within this range. Also, the voltage for Pin 7 is undefined with the IC itself. The AFC voltage varies, for example, as shown below by the VCO characteristics. The AFC voltage follows the VCO characteristics because this voltage is independent of the slope of the S curve. In other words, the CXA3176N operates according to the VCO characteristics when the VCO characteristics have the linearity with respect to the voltage and the VCO characteristics can be controlled within the range shown in the graph below. A Pin 6 voltage 4 (VCC–0.2)V B C 0.4V fo Input frequency —11— CXA3176N 14) Sensitivity Adjustment Method The constants shown in the Application Circuit are for the standard external parts. However, adjustment may be necessary depending on the conditions of use, characteristics of external parts, and the RF system circuit and decoder connected to the IF IC, etc. Adjust the sensitivity according to the following procedures. a) MIX IN matching When using a matching circuit between the RF system circuit and MIX IN of the CXA3176N, adjust the trimmer to obtain the optimal sensitivity while monitoring the AUDIO output. b) Local input level The mixer circuit gain is dependent on the local signal input level to OSC IN. The input level to OSC IN should be set as high as possible within the range of –6 to +2 dBm as shown in the graph of “Local input level vs. Mixer gain characteristics”. However, care should be taken as raising the input level above +2 dBm will cause the sensitivity to drop. When creating the local signal using the internal oscillator circuit, the oscillation level varies according to the external capacitances attached to Pins 1 and 2 and the characteristics of the used crystal. Therefore, be sure to adjust the external capacitance values attached to Pins 1 and 2 according to the crystal characteristics. OSC 1 2 C1 C2 VCC C1 and C2 have the following range in the figure above. C1 ≥ C2 C1 = C2 to C1 =5C2 As for the ratio of C1 to C2, the oscillation stabilizes as C1 approaches equality with C2. The oscillation level decreases as the C1 and C2 values become larger, and increases as the C1 and C2 values become smaller. Use a FET probe to confirm the local input level. c) LPF constant (when the CXA3176N is used for the pager) The data filter cut-off may need to be changed depending on the characteristics of the connected decoder. Adjust the capacitance values of Pins 9 to 12 while checking the incoming sensitivity including the decoder. If the capacitance values are too large, the detector output waveform will deviate at high data rates, causing the sensitivity to drop. Conversely, if the capacitance values are too small, the LPF will be easily affected by noise, causing the sensitivity to drop. Adjust capacitance values of Pins 9 to 12 so that the capacitance value described in “12) LPF Constant” becomes smaller. —12— CXA3176N d) AFC The CXA3176N uses the AFC to correct the IF frequency deviation. WHen the IF frequency deviation amount is large, correction takes time and may lower the sensitivity. Adjust the oscillator frequency of the local oscillator so that the center frequency of the signal input to Pin 5 (IF IN) is as close to 450 kHz as possible. 15) CXA3176N Standard Board Description • Outline This board contains the external parts shown in the Application Circuit in order to evaluate the CXA3176N operation • Features The following CXA3176N basic operations can be checked. 1) Battery saving and other mode switching 2) AFC pin 3) The RSSI pin output is the low impedance because it is output via the buffer. • Method of use 1) Input the CXA3176N supply voltage VCC1=1.4 V and VCC2=3 V. This IC operates with a single power supply. 2) The CXA3176N uses a 21.245 MHz crystal. Input the RF signal from the RF pin and use this IC in the condition where IF=450 kHz. 3) The AFC pin voltage is undefined with the IC itself because the current output circuit is employed for the AFC. For the evaluation, be sure to apply the bias externally to the AFC pin or to make the AFC loop. 4) Set the mode switches. • Mode switch setting Mode switches S1 and S2 are provided in two locations in the board. Each basic operation can be confirmed by switching these mode switches while referring to the board layout. See the table in “11) Control Pins” for the mode switching. • Device specification See these specifications for the IC specifications. The ICs for this evaluation board are ES specification. • Circuit diagram The circuit diagram is the same as the Application Circuit in these Specifications. —13— CXA3176N 15) -1. [Board Layout] VCC GND VCC2 GND 24 13 1 12 ON S1 S2 RF PNP ON OFF OFF XTAL CERAFIL DISK GND 3176 EVALUATION BOARD 15) -2. [Mode Switch Pattern] Slow High Quick ON Low Sleep High Active S2 S1 ON Low OFF OFF < CHARGE > < B.S. > —14— CXA3176N 15) -3. List of Standard Board Parts Part # Remarks (Manufacture) Note R5 R4 (RIVER) E12 series 1/8W 6.8 P to 45 P C2 TZ03P450FR169 (MURATA PRODUCTS) TRIMMER CAPACITOR 15 P 22 P 100 P C5 C4 C15 C12 C13 C14 C3 C8 C10 Value Resistor 5.6 k 100 k Capacitor 470 P 1000 P 0.01 µ 1µ C11 C6 C7 C9 10 µ DD100 series temperature characteristics type B (MURATA PRODUCTS) RPE131F103Z50 (MURATA PRODUCTS) 25 V 1 µ (SHIN-EI TUSHIN KOGYO CO., LTD.) 25 V 10 µ (SHIN-EI TUSHIN KOGYO CO., LTD.) CERAMIC CAPACITOR E12 series (high dielectric constant type) MONOLITHIC CERAMIC CAPACITOR RPE series ELECTROLYTIC CAPACITOR E6 series Inductor L1 EL0405 (TDK Products) E12 series 2.5 mm pitch (Lead Pitch) PNP 2SA1015 (TOSHIBA CORPORATION) Vceo Ic Pc Hfe fc –50 V –150 m 400 m 70 to 400 80 M XTAL NR-18BN (NIHON DEMPA KOGYO CO., LTD.) CERAFIL CFWS450D (MURATA PRODUCTS) 450 kHz 1.5 kΩ CDBC450CX50 —15— (MURATA PRODUCTS) 450 kHz 1.8 µH Active Component Crystal 21.245 MHz Ceramic Filter Ceramic Discriminator DISC CXA3176N Switch S1 S2 ATE1D-2M3-10 (FUJISOKU CORPORATION) RF HRM300-25 (HIROSE ELECTRIC CO., LTD.) AC/DC AC/DC ON-ON (1 poles) 48 V 50 mA 20 mA 1 µA Connector SMA CONNECTOR Pin ×5 ×6 Mac 8 test pin ST-1-3 (Mac eight) Mac 8 test pin LC-2-G (Mac eight) —16— L=10 mm 0.8 φ Max. Min. CXA3176N Example of Representative Characteristics Current consumption characteristics ICC2 (at VCC1 1.4V) 1.1 0.13 ICC1 (at VCC2 3.0V) 1.0 0.9 0.12 ICC2 (Pin 19) current (mA) ICC1 (Pin 4) current (mA) 1.2 0.8 0 1.0 2.0 3.0 4.0 Supply voltage (V) Mixer input audio response and RSSI characteristics 0 Audio response (dB) 10 20 30 VCC2 3.0V VCC1 1.4V RF 21.7MHz fDEV 4.5kHz fMOD 4kHz Lo 21.25MHz 0dBm 0dB=630mVrms T=25°C 10P to 120P 1000P S/N 24 1.8µ 40 1000 RSSI 500 50 60 –120 –110 –100 –90 –80 –70 –60 RF input level (dBm) Local input level vs. Mixer gain characteristics 10 Mixer gain (dB) VCC1 1.4V VCC2 3.0V RF 21.7MHz –60dBm 0 Lo 21.25MHz With IF filter load Mixer gain is the level difference between Pin 3 and Pin 24 –10 –20 –10 Local input level (dBm) —17— 0 –50 –40 –30 0 RSSI output voltage (mV) S CXA3176N Mixer input frequency vs. Gain characteristics Mixer gain (dB) 1.0 0 VCC2 3.0V VCC1 1.4V RF –60dBm Lo (RF –0.45) MHz 0dBm –10 1M 10M 100M Pin 24 input frequency (Hz) Mixer I/O characteristics and 3rd-order intercept point 0 VCC1 1.4V VCC2 3.0V fo 21.7MHz f1 21.725MHz f2 21.75MHz Pin 3 output level (dBm) –20 fo Lo 21.25MHz with IF filter load –40 f1 + f2 –60 –80 –60 –40 –20 0 Pin 24 input level (dBm) Cut-off characteristics of audio filter 0 VCC1 1.4V VCC2 3.0V Response (dB) –10 –20 –30 –40 –50 –60 100 1k Input frequency (Hz) —18— 10k 0dBm CXA3176N Pin 16 voltage (mV) S curve characteristics 4.7k 300 8 VCC1 VCC1 1.4V VCC2 3V CDBC 450 CX50 (MURATA MFG. CO., LTD) IF –40dBm 200 5 50 100 440 445 450 455 460 Pin 5 input frequency (kHz) RSSI output voltage temperature chatacteristics 1000 25°C Pin 13 voltage (mV) … 75°C … 25°C … –20°C 10P to 120P 1000P 24 –20°C 1.8µ 500 75°C VCC1 1.4V VCC2 3.0V RF 21.7MHz fDEV 4.5kHz fMOD 4kHz Lo 21.25MHz 0dB –120 –110 –100 –90 –80 –70 –60 –50 RF input level (dBm) AFC output current characteristics 0.6 Fast mode VCC1 1.4V VCC2 3.0V 50 Pin 7 215mV fixed (external power supply) 0.2 0 0 –0.2 Slow mode –0.4 –50 –0.6 80 120 160 200 240 280 Pin 16 voltage (mV) 320 —19— 360 400 Fast (Pin 7) current (µA) Slow (Pin 7) current (µA) 0.4 –40 –30 –20 CXA3176N AFC amplifier characteristics 3 VCC2 3.0V VCC1 1.4V Pin 6 voltage (V) 2 1 0 500 1000 Pin 7 voltage (mV) LVA characteristics LVA comparator output voltage VCC2 3.0V High Low 1050 1060 1070 1080 1090 Pin 4 voltage (mV) —20— 1100 1110 CXA3176N Package Outline Unit : mm 24PIN SSOP(PLASTIC) + 0.2 1.25 – 0.1 ∗7.8 ± 0.1 0.1 24 13 ∗5.6 ± 0.1 7.6 ± 0.2 A 1 12 b 0.13 M 0.5 ± 0.2 (0.15) (0.22) 0.1 ± 0.1 DETAIL B : SOLDER b=0.22 ± 0.03 + 0.03 0.15 – 0.01 + 0.1 b=0.22 – 0.05 + 0.05 0.15 – 0.02 0.65 B DETAIL B : PALLADIUM 0° to 10° NOTE: Dimension “∗” does not include mold protrusion. DETAIL A PACKAGE STRUCTURE PACKAGE MATERIAL EPOXY RESIN SONY CODE SSOP-24P-L01 LEAD TREATMENT SOLDER/PALLADIUM PLATING EIAJ CODE SSOP024-P-0056 LEAD MATERIAL 42/COPPER ALLOY PACKAGE MASS 0.1g JEDEC CODE NOTE : PALLADIUM PLATING This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame). —21—