TDA1220B AM-FM QUALITY RADIO The TDA1220B is a monolithic integrated circuit in a 16-lead dual in-line package. It is intended for quality receivers produced in large quantities. The functions incorporated are: DIP-16 Plastic (0.25) AM SECTION – Preamplifier and double balanced mixer – One pin local oscillator – IF amplifier with internal AGC – Detector and audio preamplifier FM SECTION – IF amplifier and limiter – Quadrature detector – Audio preamplifier The TDA1220B is suitable up to 30MHz AM and for FM bands (including 450KHz narrow band) and features: – Very constant characteristics (3V to 16V) – High sensitivity and low noise – Very low tweet ORDERING NUMBER : TDA 1220BK – Sensitivity regulation facility (*) – High recovered audio signal suited for stereo decoders and radio recorders – Very simple DC switching of AM-FM – Low current drain – AFC facility (*) Maximum AM sensitivity can be reduced by means of a resistor (5 to 12KΩ) between pin 4 and ground. BLOCK DIAGRAM March 1993 1/18 TDA1220B ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit 16 V 400 mW -20 to 85 °C Vs Supply voltage Ptot Total power dissipation at Tamb < 110°C Top Operating temperature Storage and junction temperature -55 to 150 °C Tstg, Tj PIN CONNECTION (Top view) THERMAL DATA Symbol Rth-j-amb 2/18 Parameter Thermal resistance junction-ambient max Value Unit 100 °C/W TDA1220B ELECTRICAL CHARACTERISTICS ( Tamb = 25 °C, Vs = 9V unless otherwise specified, refer to test circuit) Symbol Parameter Vs Supply voltage Id Drain current Test conditions Min. Typ. 3 Max. Unit 16 V FM 10 15 mA AM 14 20 mA 12 25 µV AM SECTION (fo = 1 MHz; fm = KHz) Vi Input sensitivity S/N S/N = 26 dB m = 0.3 Vi = 10 mV m = 0.3 45 52 dB dB Vi AGC range ∆Vout = 10 dB m = 0.8 94 100 Vo Recovered audio signal (pin 9) Vi = 1 mV m = 0.3 80 130 200 mV d Distortion m = 0.3 0.4 1 % m = 0.8 1.2 Vi = 1 mV % VH Max input signal handling capability m = 0.8 Ri Input resistance between pins 2 and 4 m=0 7.5 KΩ Ci Input capacitance between pins 2 and 4 m=0 18 pF Ro Output resistance (pin 9) Tweet 2 IF d < 10% 1 4.5 m = 0.3 Vi = 1 mV Tweet 3 IF V 7 9.5 KΩ 40 dB 55 dB FM SECTION (fo = 10.8 MHz; fm = 1 KHz) µV Vi Input limiting voltage -3 dB limiting point AMR Amplitude modulation rejection ∆f = ±22.5 KHz Vi = 3 mV m = 0.3 40 50 dB S/N Ultimate quieting ∆f = ±22.5 KHz Vi = 1 mV 55 65 dB d Distortion ∆f = ±75 KHz Vi = 1 mV d Distortion ∆f = ±22.5 KHz Vi = 1 mV d Distortion (double tuned) Vo Recovered audio signal (pin 9) Ri Input resistance between pin 16 and ground 6.5 KΩ Ci Input capacitance between pin 16 and ground 14 pF Ro Output resistance (pin 9) 22 36 0.7 1.5 % 0.25 0.5 % 0.1 ∆f = ±22.5 KHz Vi = 1 mV 80 4.5 110 7 % 140 9.5 mV KΩ 3/18 TDA1220B Figure 1. Test circuit Figure 2. PC board and component layout (1:1 scale) of the test circuit 4/18 TDA1220B Figure 3. Audio output, noise and tweet levels vs. input signal (AM section) Figure 4. Distortion vs. input signal and modulation index (AM section) Figure 5. Audio output vs. supply voltage (AM section) Figure 6. Audio output and noise level vs. input signal (FM section) Figure 7. Distortion vs. input signal (FM section) Figure 8. Audio output vs. supply voltage (FM section) Figure 9. Amplitude modulation rejection vs. input signal (FM section) Figure 10. ∆ DC output voltage (pin. 9) vs. frequency shift (FM section) Figure 11. ∆ DC output voltage (p i n 9) vs. amb ien t temperature (FM section) 5/18 TDA1220B APPLICATION INFORMATION AM Section RF Amplifier and mixer stages The RF amplifier stage (pin 2) is connected directly to the secondary winding of the ferrite rod antenna or input tuned circuit. Bias is provided at pin 4 which must be adequately decoupled. The RF amplifier provides stable performance extending beyond 30 MHz. The Mixer employed is a double - balanced multiplier and the IF output at pin 3 is connected directly to the IF filter coil. Local oscillator The local oscillator is a cross coupled differential stage which oscillates at the frequency determined by the load on pin 1. The oscillator resonant circuit is transformer coupled to pin 1 to improve the Q factor and frequency stability. The oscillator level at pin 1 is about 100 mV rms and the performance extends beyond 30 MHz, however to enhance the stability and reduce to a minimum pulling effects of the AGC operation or supply voltage variations, a high C/L ratio should be used above 10 MHz. An external oscillator can be injected at pin 1. The level should be 50 mV rms and pin 1 should be connected to the supply via a 100W resistor. IF Amplifier Detector The IF amplifier is a wide band amplifier with a tuned output stage. The IF filters can be either LC or mixed LC/ceramic. AM detection occurs at pin 7. A detection capacitor is connected to pin 6 to reduce the radiation of spurious detector products. The Audio output is at pin 9 (for either AM or FM); the IF frequency is filtered by an external capacitor which is also used as the FM mono de-enphasis network. The audio output impedance is about 7KΩ and a high impedance load (~ 50KΩ) must be used. AGC Automatic gain control operates in two ways. With weak signals it acts on the IF gain, maintaining the maximum S/N. For strong signals a second circuit intervenes which controls the entire chain and allows signal handling in excess of one volt (m = 0.8). At pin 8 there is a carrier envelope signal which is filtered by an external capacitor to remove the Audio and RF content and obtain a mean DC signal to drive the AGC circuit. 6/18 TDA1220B APPLICATION INFORMATION (continued) FM Section IF Amplifier and limiter The 10.7 MHz IF signal from the ceramic filter is amplified and limited by a chain of four differential stages. Pin 16 is the amplifier input and has a typical input impedance of 6.5 KW in parallel with 14 pF at 10.7 MHz. Bias for the first stage is available at pin 14 and provides 100% DC feedback for stable operating conditions. Pin 15 is the second input to the amplifier and is decoupled to pin 14, which is grounded by a 20 nF capacitor. An RLC network is connected to the amplifier output and gives a 90° phase shift (at the IF centre frequency) between pins 13 and 12. The signal level at pin 13 is about 150 mV rms FM Detector The circuit uses a quadrature detector and the choise of component values is determined by the acceptable level of distortion at a given recovered audio level. With a double tuned network the linearity improves (distortion is reduced) and the phase shift can be optimized; however this leads to a reduction in the level of the recovered audio. A satisfactory compromise for most FM receiver applications is shown in the test circuit. Care shoul be taken with the physical layout. The main recommandations are: • Locate the phase shift coil as near as possible to pin 13. • Shunt pins 14 and 16 with a low value resistor (between 56Ω and 330Ω). • Ground the decoupling capacitor of pin 14 and the 10.7 MHz input filter at the same point. AM-FM Switching AM-FM switching is achieved by applying a DC voltage at pin 13, to switch the internal reference. Typical DC voltages (refer to the test circuit) Pins 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Unit AM 9 1.4 9 1.4 1.4 8.4 9 0.7 1.9 9 0 0.1 0.1 8.5 8.5 8.5 V FM 9 0.02 9 0.02 0.02 8.5 9 0 1.7 9 0 9 9 8 8 8 V 7/18 TDA1220B APPLICATION SUGGESTION Reccomended values are referred to the test circuit of Fig. 2. Smaller than recommended value Larger than recommended value Increase of the distortion at low audio frequency Increase of the AGC time constant FM amplifier bypass Reduction of sensitivity – Bandwidth increase – Higher noise 68 pF Ceramic filter coupling IF bandwidth reduction IF bandwidth increase C7 100 nF FM detector decoupling Danger of RF irradiation C8 100 nF Power supply bypass Noise increase of the audio output C9 10 µF AGC bypass Increase of the distortion at low audio frequency C10 (*) 56 pF Tuning of the AM oscillator at 1455 KHz C11 6.8 nF 50 µs FM de-enphasis C12 100 nF Output DC decoupling Low audio frequency cut C13 220 µF Power supply decoupling Increase of the distortion at low frequency C16 2.7 nF AM detector capacitor Low suppression of the IF frequency and harmonics R1 (*) 68 ohm FM input matching R2 (*) 56 ohm AM input matching R3 330 ohm Ceramic filter matching Audio output decrease and lower distortion R4 8.2 Kohm FM detector coil Q setting Audio output decrease and higher AMR R5 560 ohm FM detector load resistor Lower IF gain and Lower AGC range R6 82 Kohm AM detector coil Q setting R7 2.2 Kohm 455 KHz IF filter matching R8 3.3 Kohm 455 KHz IF filter matching Part number Recommended value C1 100 µF AGC bypass C2 (*) 100 nF AM input DC cut C3 (*) 10 nF FM input DC cut C4 C5 20 nF 20 nF C6 (*) Only for test circuit 8/18 Purpose Increase of the AGC time constant Increase of the audio distortion Audio output increase and higher distortion Higher IF gain and lower AGC range TDA1220B APPLICATION INFORMATION (continued) Figure 12. Portable AM/FM radio 9/18 TDA1220B APPLICATION INFORMATION (continued) Figure 13. PC board and component layout of the fig. 12 1 : 1 scale 10/18 TDA1220B APPLICATION INFORMATION (continued) F1 - 10.7 MHz IF Coil Co (pF) f (MHz) – Qo TURNS 1-3 1-2 2-3 4-6 10.7 110 6 8 2 f (KHz) Qo – TOKO - FM1 - 10x10 mm. 154 AN - 7A5965R F3 and F5 - 455 KHz IF Coil Co (pF) 1.3 TURNS 1-3 1-2 2-3 4-6 455 70 57 116 24 f (KHz) Qo 180 TOKO - AM3 - 10x10 mm. RLC - 4A7525N F4 - FM Detector Coil Co (pF) 1.3 TURNS 1-3 1-3 – – 12 – – 82 10.7 100 f (kHz) L (µH) 1-3 Qo 1-3 1-2 2-3 4-6 796 220 80 2 75 8 TOKO - 10x10 mm. KACS - K586 HM F6 - AM Oscillator Coil TURNS TOKO - 10x10 mm. RWO + 6A6574N L5 - Antenna Coil f (KHz) 796 L (µH) Qo 1-2 1-2 TURNS 1-2 3-4 105 7 WIRE: LITZ - 15x0.05 mm. CORE: 10x80 mm. 11/18 TDA1220B APPLICATION INFORMATION (continued) Typical performance of the radio receiver of fig. 12 (Vs = 9V) Parameter WAVEBANDS SENSITIVITY Test Conditions FM 87.5 to 108 MHz AM 510 to 1620 KHz FM S/N = 26dB ∆f = 22.5KHz 1 µV AM S/N = 6dB m = 0.3 1 µV AM S/N = 26dB m = 0.3 10 µV FM Po = 0.5W ∆f = 22.5KHz 0.25% ∆f = 75KHz 0,7% m = 0.3 0.4% m = 0,8 0,8% ∆f = 22.5KHz 64 dB m = 0.3 50 dB DISTORTION (fm = 1KHz) AM SIGNAL TO NOISE (fm = 1KHz) Value FM Vi = 100 µV Po = 0.5W Vi = 100 µV AM Po = 0.5W Vi = 1 mV AMPLITUDE MODULATION REJECTION TWEET FM Vi = 100 µV 2nd H. f = 911 KHz 0.3% 3rd H. f = 1370 KHz 0.07% QUIESCENT CURRENT SUPPLY VOLTAGE RANGE 12/18 ∆f = 22.5KHz m = 0.3 50 dB 20 mA 3 to 12V TDA1220B APPLICATION INFORMATION (continued) Figure 14. Low cost 27 MHz receiver Figure 15. L2 Oscillator coil Figure 16. L1 Antenna Coil Coil support: Toko 10K Primary winding: 10 Turns of enamelled copper wire 0.16 mm diameter (pins 3-1). Secondary winding: 4 Turns copper wire 0.16 mm diameter (pins 6-4) Coil support: Toko 10K Primary winding: as L2 (pins 3-1) Secondary winding: 2 Turns copper wire 0.16 mm diameter (pins 6-4) Figure 17. Low cost 27 MHz receiver with external xtal oscillator 13/18 TDA1220B APPLICATION INFORMATION (continued) Figure 18. 455 KHz FM narrow band IF Figure 18. P.C. board and component layout of the circuit of fig. 18 14/18 TDA1220B APPLICATION INFORMATION (continued) Figure 20. Discriminator "S" curve response (circuit of fig. 18) Figure 21. Application in sound channel of multistandard TV or in parallel AM modulated sound channel (AM section only). 15/18 TDA1220B ELECTRICAL CHARACTERISTICS (Vs = 12V) AM Section (fo = 39MHz; fm = 15KHz) Parameter Audio out (m = 0.3) Typ Unit 60 mV S/N (Vi = 100 mV; m = 0.3) 37 dB S/N (Vi = 1mV; m = 0.3) 55 dB S/N (Vi = 10mV; m = 0.3) 56 dB AGC range (m = 0.8, ∆Vout = 3dB) 65 dB Max input signal handling (m = 0.8; d = 5%) 150 mV – 3dB bandwidth 600 KHz m = 0.3) 2 % (Vi = 1mV; m = 0.3) 1 % (Vi = 10mV; m = 0.3) 0.8 % (Vi = 100 µV; m = 0.8) 7 % (Vi = 1mV; m = 0.8) 5 % (Vi = 10mV; m = 0.8) 3 % Typ Unit 3 µV Distortion (Vi = 100 µV; FM Section (fo = 5.5MHz; fm = 1KHz) Parameter –3dB input limiting voltage (∆f = 25KHz) AMR (∆f = +25KHz; m = 0.3; Vi = 100 µV) 40 dB (∆f = +25KHz; m = 0.3; Vi = 1mV) 58 dB (∆f = +25KHz; m = 0.3; Vi = 10mV) 54 dB S/N (∆f = ±25KHz; Vi = 100 µV) 51 dB S/N (∆f = ±25KHz; Vi = 1 mV) 70 dB S/N (∆f = ±25KHz; Vi = 10mV) 70 dB Distortion (∆f = ±25KHz; Vi = 100 µV) 0.5 % (∆f = ±25KHz; Vi = 1 mV) 0.6 % (∆f = ±25KHz; Vi = 10 mV) 0.6 % (∆f = ±50KHz; Vi = 100 µV) 1 % (∆f = ±50KHz Vi = 1mV) 1 % (∆f = ±50KHz; Vi = 10mV) 1 % Recovered audio (∆f = ±15KHz; Vi = 1 mV) Recovered audio can be varied by variation of 3.3K ohm resistor in parallel with the discriminator coil) 70 mV Max input signal handling 1 V Note: AM performance at 39MHz can be improved by mean of a selective preamplifier stage. 16/18 TDA1220B DIP16 PACKAGE MECHANICAL DATA mm DIM. MIN. a1 0.51 B 0.77 TYP. inch MAX. MIN. TYP. MAX. 0.020 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 F 7.1 0.280 I 5.1 0.201 L Z 3.3 0.130 1.27 0.050 17/18 TDA1220B Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 18/18