AN7298FBP. FM-IF, NC, and MPX IC for car radio. ICs for FM/AM Tuner. Overview. Features. Applications

Transcription

1 FM-IF, NC, and MPX IC for car radio Overview The is an IC for car radio. The FM-IF, NC (Noise Canceler) and MPX functions are integrated into a single chip. The IC has the higher functions than our conventional IC (AN7292NSC) and the characteristics of multi-pass detection, mute and SD functions are improved Unit: mm ±0. 2.0± ±0.4 Features IF sensitivity is high. (limiting sensitivity 26 dbµ) Adjustment-free VCO (92 khz) Good linearity of S-meter output (adjusting funciton) Applications Car radios 0.± ± ±0.4 2 QFH048-P (0.55).3±0..3±0. 2.8±0.2

2 Block Diagram nd limiter Reg. Quad det. AFC amp. Band det. SD IF count Mute amp st limiter PNL Pulse det. AGC V cont det. V cont DC amp. Pilot det. Pilot canceler Multipath detector ASC. ATC stereo demod. Divider VCO GND V CC

3 Pin Descriptions Pin No. Description ASC adjustment 2 ATC adjustment 3 Separation adjustment 4 ATC LPF 5 R-ch. output 6 L-ch. output 7 Control voltage output 8 Band mute control 9 Soft mute filter 0 Phase detection filter Forced monaural 2 Phase detection filter 2-3 SD startup time constant setting 4 Phase detection filter VCO 6 Phase detection filter 3 7 Pilot canceler negation filter 8 PNL LPF 9 PNL LPF 20 PNL gate pulse filter 2 PNL AGC 22 PNL input 23 PNL HPF 24 IF-counter output stop Pin No. Description 25 IF detection output 26 PNL output hold 27 SD/IF counter output 28 SD sensitivity adjustment 29 AFC output 30 V CC 3 IF detection coil 32 Limiter output 33 Soft mute adjustment 34 Stereo lamp drive 35 2nd limiter output 36 GND 37 Mute adjustment 38 st limiter 39 Reference voltage 40 st limiter output GND 4 st limiter bias 42 IF input 43 Mute slope adjustment 44 Control voltage adjustment 45 Control voltage output 46 Control voltage input 47 ASC 48 Control voltage detection Absolute Maximum Ratings Parameter Symbol Rating Unit Supply voltage V CC 9.7 V Supply current I CC 48 ma Power dissipation *2 P D 30 mw Operating ambient temperature * T opr 30 to +80 C Storage temperature * T stg 55 to +25 C Note) * : All parameter values except for the power dissipation, the operating ambient temperature and the storage temperature are T a = 25 C. *2 : Power dissipation of IC alone at T a = 80 C. 3

4 Recommended Operating Range Parameter Symbol Range Unit Supply voltage V CC 7.2 to 9.6 V Electrical Characteristics at V CC = 8 V, f IN = 0.70 MHz, f mod = khz 30%FM, T a = 25 C Parameter Symbol Conditions Min Typ Max Unit Control voltage V C Without input, pin 45 DC voltage V Control voltage 2 V C2 V IN = 40 dbµ, pin 45 DC voltage V Control voltage 3 V C3 V IN = 70 dbµ, pin 45 DC voltage V Control voltage 4 V C4 V IN =00 dbµ, pin 45 DC voltage V Control voltage 5 V C5 V C5 = V C3 V C V Control voltage 6 V C6 V C6 = V C4 V C V AFC offset voltage V AFC Without input, DC voltage between V pin 29 and pin 39 Output level L V OL V IN = 70dBµ, pin 6 AC voltage mv[rms] Output level R V OR V IN = 70dBµ, pin 5 AC voltage mv[rms] Channel balance CB CB = 20Log (V OL /V OR ) db Limiting sensitivity V lim V OL to 0 db. Input when pin dbµ AC voltage drops by 3 db Residual pilot voltage V PC Pin 26 output when V IN = 70 dbµ, mv[rms] pilot signal 0% modulation Stereo lamp on-level Lamp ON Modulation with pilot signal only, % DC voltage of pin 34 is below 2 V Stereo lamp off-level Lamp OFF Modulation with pilot signal only db Ratio of stereo lamp on and off level Separation L-ch. Sep L V IN = 70 dbµ, L+R = 90% db Pilot 0% Separation R-ch. Sep R V IN = 70 dbµ, L+R = 90% db Pilot 0% Capture range CR V IN = 70 dbµ, % pilot signal 6.5% modulation Counter output level V IF V IN = 70 dbµ, pin 28 = 0V, mv[rms] pin MHz, output voltage Counter output level 2 V IF2 V IN = 70 dbµ, pin 28 = V CC, mv[rms] pin 27 AC output voltage Power supply current I tot Without input, pin = 0 V ma Monaural THD (L-ch.) THD L Monaural input 400 mv, khz, % L-ch. distortion Monaural THD (R-ch.) THD R Monaural input 400 mv, khz, % R-ch. distortion 4

5 Electrical Characteristics at V CC = 8 V, f IN = 0.70 MHz, f mod = khz 30%FM, T a = 25 C (continued) Parameter Symbol Conditions Min Typ Max Unit Stereo THD (L-ch.) THD SL Stereo, L+R = 360 mv,v P = 40 mv, % L-ch. distortion Stereo THD (R-ch.) THD SR Stereo, L+R = 360 mv,v P = 40 mv, % R-ch. distortion AGC voltage V AGC Input = 0, R S = 600 Ω, V pin 2 DC voltage AGC voltage 2 V AGC2 Input V IN2 = 2 mv[rms], V 50 khz, pin 2 DS voltage Noise detection voltage V DET V IN2 = 00 mv[rms],50 khz, V pin 20 DC voltage Gate pulse width PW V IN2 = 0.3 V[p-p], t W = µs, µs f= khz, pin 26 output pulse width Residual noise voltage V NR V IN2 = V[p-p], t W =0 µs, f= khz, mv[rms] input through LPF, L-ch. output SD bandwidth SDW Bandwidth when SD output (pin khz 27) is over 4.5 V, V 28 = 2.7 V SD sensitivity SDS Input when SD output (pin 27) is dbµ over 4.5 V, V 28 = 2.7 V 5

6 Application Circuit Example GND V CC (8 V) AFC output SD output Counter output VAF (IF detection output) IF counter stop V ref IF input 50 Ω V cont R out L out Band mute On Off Monaural 2 Stereo Forced monaural 6