BA1451F Audio ICs AM radio / FM IF stereo system IC BA1451F The BA1451F is a tuner system IC for electronic tuning for AM radios, FM IF, and MPX. It has been developed for HiFi component applications. The MPX VCO circuit requires no adjustment, which will enable a reduction in the number of production line processes. In particular, the laser lock technique used in the VCO means that no external adjustment is required. !Applications Synthesized tuner for HiFi components. !Features 1) Built-in AM monaural radio, FM IF amplifier/detector, and FM stereo demodulator. 2) DTS (both SD and IF count) compatible. 3) Built-in reference voltage power supply provides good shortwave band frequency stability. 4) Good FM stability. 5) The FM MPX VCO uses laser locking making adjustment and external components unnecessary. 6) Built-in forced monaural operation function for MPX (VCO stops, and LED goes off). 7) Low cutoff of audio is possible to improve AM fidelity. 8) MPX VCO stops in AM mode. 9) Audio muting is possible when an IF request is made. !Block diagram 24 23 22 21 20 19 17 16 15 14 13 AM IF AM MIX AM OSC 18 SD Vreg AM DET AGC 1/2 SW 1/2 PD FM DET FM IF Vcc 1 2 SD DET 3 LED DRIVER DECODER VCO COMP GND 4 5 6 7 8 9 10 11 12 BA1451F Audio ICs !Absolute maximum ratings Parameter Symbol Limits Power supply voltage VCC 9.0 Power dissipation Pd 450∗ Unit V 1 mW Operating temperature Topr −25∼+75 ˚C Storage temperature Tstg −55∼+125 ˚C ∗ 1 Reduced by 4.5mW for each increase in Ta of 1˚C over 25˚C. !Recommended operating conditions (Ta=25°C) Parameter Symbol Min. Typ. Max. Unit VCC 3.8 5.0 8.0 V Power supply voltage !Input and output circuits Pin No. Function Quiescent voltage (V) FM AM Internal circuit VCC 2 Vreg 23 1 FM IF amplifier input 330Ω 1 Connect to an FM ceramic filter. 2.1 2.1 5.0 5.0 0.25 0 0 0 5.0 5.0 − − − − GND 4 2 VCC 3 VCC 2 FM tuning ON level adjustment 3 Connect a resistor from this pin to GND to set the required ON level for the tuning indicator. 15kΩ GND 4 4 GND 5 VCC 2 5 FM discriminator Connect to the discriminator coil. 5pF GND 4 6 Tuning indicator Connect to a tuning indicator display device (eg. LED) 7 Stereo indicator Connect to a stereo indicator display device (eg. LED) 6/7 GND 4 BA1451F Audio ICs Pin No. Function 8 · IF request Output the IF signal to pin9 excess of 4.0V. Stops the IF signal at equal to or less than 3.0V. · MUTE Apply to muting excess of 2.0V. Off the muting at equal to or less than 1.0V. Quiescent pin voltage (V) FM AM Internal circuit 10kΩ MUTE IF OUT 8 10kΩ 0 0 4.2 4.2 1.5 1.5 1.5 1.5 2.1 0 2.1 2.1 GND 4 VCC 2 9 IF output Output for the IF signal. 9 GND 4 VCC 2 10 R-channel output 11 5kΩ 10/11 L-channel output GND 4 Vreg 23 82kΩ 12 · PLL filter Connect to a lag/lead filter. AM/FM 12 · AM / FM band switch AM band when connected to GND. GND 4 13 · Pilot filter Connect to a capacitor. 13 Vreg 23 4kΩ · Forced monaural Forced monaural operation connecting to get a resistor to mediate. (Recommended value : 10kΩ to ground.) MONO GND 4 BA1451F Audio ICs Pin No. Function Quiescent pin voltage (V) Internal circuit FM AM 2.1 2.1 2.1 2.1 2.1 2.1 0 0 5.0 5.0 5.0 5.0 2.1 2.1 MPX input Vreg 23 20kΩ Input the FM detector output . 100kΩ VCC 2 14 14 MPX input 15 Input the AM detector output after low cut. 15 GND 4 VCC 2 AM/FM detector output 16 Connect to the following stage MPX and FM low pass filter. 16 5kΩ GND 4 17 VCC 2 AM AGC 17 Connect to a capacitor. 20kΩ GND 4 3kΩ VCC 2 18 AM IF input 18 Connect to an AM ceramic filter. GND 4 19 AM mixer output 19 VCC 2 30kΩ Vreg 23 Connect to primary side of AM IFT. 20 AM antenna 20 Connect to AM antenna. GND 4 BA1451F Audio ICs Pin No. Function Quiescent pin voltage (V) FM AM Internal circuit 21 VCC 2 FM detector bandwidth adjustment 21 Connect a resistor from this pin to the reference voltage supply to set the required detector bandwidth. 2.1 2.1 2.1 2.1 2.1 2.1 1.7 1.4 4.3kΩ GND 4 23 Reference voltage supply Connected to a capacitor. AM local oscillator 22 100Ω Vreg 23 22 Connect to the AM OSC circuit. 24 AM local oscillator output 24 GND 4 AM OSC output. !Electrical characteristics (Unless otherwise specified, Ta=25°C and VCC=5V) FM IF MPX signal source : fiN=10.7MHz, modulation 1kHz, 75kHzdev (100%) 19kHz 7.5kHzdev (10%) AM : fiN=1000kHz, modulation 1kHz 30% Parameter Quiescent current FM Quiescent current AM <FM IF MPX> Detector output voltage −3dB limiting sensitivity Signal-to-noise ratio Channel balance AM suppression ratio Channel separation Total harmonic distortion Station detector sensitivity Station detector bandwidth IF OUT output voltage <AM> Detector output voltage Usable sensitivity Signal-to-noise ratio Total harmonic distortion Station detector sensitivity IF OUT output voltage Local buffer output voltage Symbol I Q (FM) I Q (AM) Min. 13 11 Typ. 21 19 Max. 29 27 Unit mA mA Conditions VO L.S S/N C.B AMR SEP THD SDS SDSW VIF 340 34 72 −2 45 35 − 34 70 300 480 37 80 0 55 45 0.5 39 100 400 670 40 − +2 − − 1.6 44 150 530 mVrms dBµV dB dB dB dB % dBµV kHz mVP-P VIN=100dBµV,mono mono VIN=100dBµV, mono VIN=100dBµV, mono AM : V IN=60dBµV, mod=30% , 400Hz VIN=100dBµV, main VIN=100dBµV, main Input for pin 6 current ≥ 1mA VIN=100dBµV, mono IF request ON VO Q.S S/N THD SDS VIF VOBuff 70 22 42 − 21 300 140 90 25 52 0.6 26 400 200 120 28 − 1.8 31 530 280 mVrms dBµV dB % dBµV mVP-P mVrms VIN=68dBµV Input for S / N = 20dB VIN=68dBµV VIN=68dBµV Input for pin 6 current ≥ 1mA IF request ON No input No input BA1451F Audio ICs !Test circuit AM STEREO T2 L4 50 47p STEREO 100p 0.022 MONO 22 100 10 OSC OUT 10k 20k 100 6800p 0.022 Vreg 0.022 AM SG 24 1 23 22 21 20 19 18 17 16 15 14 13 SG OSC DET MIX Vreg MPX SD DET 1 2 3 Vcc 4 5 6 7 0.022 TUN. 9 11 12 AM 0.22 0.022 IFREQ 3.9k 0.01 MUTE 1 0.01 24k 50 100 10 ST. OFF FM STEREO SG SG 8 GND FM SG SG MUTE REQ. LED FM 3.3k 0. 022 +B IF OUT R-ch L-ch 0.047 L4 : AM OSC T2 : AM IFT CD1 : FM DISCRIMINATOR COIL Sumida Toko Toko Sumida Toko Fig. 1 2157-JPS-029 A7BRS-12445X CFMA-258 0236-JPS-101 A119ACS-19197N Units : R [Ω] C [µF] BA1451F Audio ICs !Application example 24 8 7 6 23 OSC Vreg OUT 5 22 21 20 BA4425F 1 2 19 18 17 16 15 14 AM BW Adj AM IN MIXOUT IFIN AGC DET MPX MPX OSC AM AM OUT IN IN 13 SD / MONO BA1451F 3 4 BPF FMIN 1 VDD SD Adj GND FM DET TUN 2 3 4 5 MUTE / ST IF REQ IF OUT 6 7 8 9 Rch Lch PD / AMFM 10 11 12 Vcc (5V) Lch OUT 18 17 16 15 14 13 12 11 10 P2 P1 P0 TUN SD IFIN P3 6 7 8 9 GND PD2 PD1 VDD FMIN AMIN XOUT XIN CE DA CL 1 2 3 4 5 Rch OUT BU2616F Vcc2 (+9V) CE DA CL TUNING TO LED etc. µ-COM STEREO Fig. 2 4 3 2 1 0 150 140 −30 AMR −40 R→L Vcc=5V, −50 fIN=10.7MHz, fm=1kHz −60 ∆f=±22.5kHzdev, −70 pilot=±7.5kHzdev Ta=25˚C, −80 AMR MOD=30%, fm=400Hz −90 −20 20 40 0 SEP L→R 130 120 110 100 N D+N (100%) 90 80 90 80 70 60 50 40 30 20 10 D+N (30%) 60 80 100 120 INPUT VOLTAGE : VIN (dBµ) Fig.3 FM input / output characteristics 70 0 TOTAL HARMONIC DISTORTION : THD (%) 5 160 −20 110 100 −3dBL, S, TUNED ON (dBµ) SEP (dB) 6 −10 Vo (mVrms) 7 180 170 S+D+N 0 Vo, AMR, SEP (dB) TOTAL HARMONIC DISTORTION : THD (%) !Electrical characteristic curves 11 10 9 fIN=10.7MHz, VIN=100dBµ, ∆f=±22.5kHzdev. (pilot=±7.5kHzdev) fIN=1kHz, Ta=25˚C, RSD=20kΩ VO 8 7 6 L→R 5 4 R→L TUNED ON −3dB L.S. 3 2 D+N (100%) 1 0 D+N (30%) 3 4 5 6 7 8 POWER SUPPLY VOLTAGE : VCC (V) Fig.4 FM characteristics vs. power suppy voltage 9 BA1451F Audio ICs 10.70 10.65 10.60 RBW=20kΩ, VIN=100dBµ Ta=25˚C 3 4 5 6 8 7 SEP 2 1 CHANNEL SEPARATION : SEP (dB) 10.75 10.55 60 TOTAL HARMONIC DISTORTION : THD (%) FM BAND WIDTH : fIN (MHz) 10.80 R→L 40 30 Vcc=5V fIN=10.7MHz VIN=100dBµ ∆f=±22.5kHzdev pilot=±7.5kHzdev Ta=25˚C THD 20 10 0 9 L→R 50 0 50 100 200 500 −10 S / N=20dB −20 VAGC (V) 2.0 VAGC −30 −40 1.0 N D+N (80%) fm=1kHz −60 MOD=30%, LED ON −70 −20 50 0 70 60 50 40 30 20 10 D+N (30%) Ta=25˚C Q.S. , TUNED ON : (dBµ) 80 100 0 120 0 10 100 9 8 7 6 5 4 3 2 1 90 OUTPUT VOLTAGE : Vo (mVrms) 90 TOTAL HARMONIC DISTORTION : THD (%) 3.0 S+D+N 0 OUTPUT VOLTAGE : VO (dB) TOTAL HARMONIC DISTORTION : THD (%) 100 10 VOUT=5V, 5k 10k 20k Fig.6 Channel separation and THD vs. frequency Fig.5 FM bandwidth vs. power supply voltage −50 fIN=1000kHz, SUB MONO 2k FREQUENCY : fm (Hz) POWER SUPPLY VOLTAGE : Vcc (V) 10 9 8 7 6 5 4 3 2 1 0 1k R L MAIN Vo 80 70 fIN=1000kHz, VIN=74dBµ, MOD=30% fm=1kHz, Ta=25˚C 60 50 40 TUNED ON 30 Q.S. 20 D+N (80%) 10 D+N (30%) 0 0 INPUT VOLTAGE : VIN (dBµ) 3 4 5 6 7 8 9 POWER SUPPLY VOLTAGE : VCC (V) Fig.7 AM input / output characteristics Fig.8 AM characteristics vs. power suppy voltage 0 0 VO VCC=5V fIN=1000MHz VIN=74dBµ MOD=30% Ta=25˚C D+N (80%) −40 −50 −60 −70 13 5.4 ± 0.2 −30 15.0 ± 0.2 24 7.8 ± 0.3 −20 1 12 1.27 0.4 ± 0.1 D+N (30%) 50 100 200 500 1k 2k 5k 0.3Min. 0.15 10k 20k FREQUENCY : fm (Hz) Fig.9 AM detector output and THD vs. frequency 0.15 ± 0.1 −10 0.11 5 10 1.8 ± 0.1 10 AM DETECTOR OUTPUT VOLTAGE : VO (dBm) TOTAL HARMONIC DISTORTION : THD (%) !External dimensions (Units : mm) SOP24