INTEGRATED CIRCUITS DATA SHEET TDA1572 AM receiver circuit Product specification File under Integrated Circuits, IC01 December 1987 Philips Semiconductors Product specification AM receiver circuit TDA1572 GENERAL DESCRIPTION The TDA1572 integrated AM receiver circuit performs all the active functions and part of the filtering required of an AM radio receiver. It is intended for use in mains-fed home receivers and car radios. The circuit can be used for oscillator frequencies up to 50 MHz and can handle RF signals up to 500 mV. RF radiation and sensitivity to interference are minimized by an almost symmetrical design. The controlled-voltage oscillator provides signals with extremely low distortion and high spectral purity over the whole frequency range, even when tuning with variable capacitance diodes. If required, band switching diodes can easily be applied. Selectivity is obtained using a block filter before the IF amplifier. Features • Inputs protected against damage by static discharge • Gain-controlled RF stage • Double balanced mixer • Separately buffered, voltage-controlled and temperature-compensated oscillator, designed for simple coils • Gain-controlled IF stage with wide AGC range • Full-wave, balanced envelope detector • Internal generation of AGC voltage with possibility of second-order filtering • Buffered field strength indicator driver with short-circuit protection • AF preamplifier with possibilities for simple AF filtering • Electronic standby switch • IF output for stereo demodulator and search tuning. QUICK REFERENCE DATA PARAMETER SYMBOL MIN. TYP. MAX. UNIT Supply voltage range VP 7,5 − 18,0 V Supply current range IP 15 − 30 mA Vi(RF) − 1,5 − µV Vi(RF) − 500 − mV Vo(IF) − 230 − mV Vo(AF) − 310 − mV − 86 − dB − 2,8 − V RF input voltage for (S+N)/N = 6 dB at m = 30% RF input voltage for 3% total harmonic distortion (THD) at m = 80% IF output voltage with Vi = 2 mV AF output voltage with Vi = 2 mV; fi = 1 MHz; m = 30%; fm = 400 Hz AGC range: change of Vi for 1 dB change of Vo(AF) Field strength indicator voltage at Vi = 500 mV; RL(11) = 2,7 kΩ VIND PACKAGE OUTLINE 18-lead DIL; plastic (SOT102); SOT102-1; 1996 August 12. December 1987 2 AM receiver circuit December 1987 3 Fig.1 Block diagram and test circuit (connections shown in broken lines are not part of the test circuit). (1) Coil data: TOKO sample no. 7XNS-A7523DY; L1 : N1/N2 = 12/32; Qo = 65; QB = 57. Filter data: ZF = 700 Ω at R3-4 = 3 kΩ; ZI = 4,8 kΩ. (2) AF output is pin 6 is not used. Philips Semiconductors Product specification TDA1572 Philips Semiconductors Product specification AM receiver circuit TDA1572 FUNCTIONAL DESCRIPTION Gain-controlled RF stage and mixer The differential amplifier in the RF stage employs an AGC negative feedback network to provide a wide dynamic range. Very good cross-modulation behaviour is achieved by AGC delays at the various signal stages. Large signals are handled with low distortion and the (S+N)/N ratio of small signals is improved. Low noise working is achieved in the differential amplifier by using transistors with low base resistance. A double balanced mixer provides the IF output signal to pin 1. Oscillator The differential amplifier oscillator is temperature compensated and is suitable for simple coil connection. The oscillator is voltage-controlled and has little distortion or spurious radiation. It is specially suitable for electronic tuning using variable capacitance diodes. Band switching diodes can easily be applied using the stabilized voltage V13-18. An extra buffered oscillator output (pin 12) is available for driving a synthesizer. If this is not needed, resistor RL(12) can be omitted. Gain-controlled IF amplifier This amplifier comprises two cascaded, variable-gain differential amplifier stages coupled by a band-pass filter. Both stages are gain-controlled by the AGC negative feedback network. The IF output is available at pin 10. Detector The full-wave, balanced envelope detector has very low distortion over a wide dynamic range. Residual IF carrier is blocked from the signal path by an internal low-pass filter. AF preamplifier This stage preamplifies the audio frequency output signal. The amplifier output has an emitter follower with a series resistor which, together with an external capacitor, yields the required low-pass for AF filtering. AGC amplifier The AGC amplifier provides a control voltage which is proportional to the carrier amplitude. Second-order filtering of the AGC voltage achieves signals with very little distortion, even at low audio frequencies. This method of filtering also gives fast AGC settling time which is advantageous for electronic search tuning. The AGC settling time can be further reduced by using capacitors of smaller value in the external filter (C16 and C17). The AGC voltage is fed to the RF and IF stages via suitable AGC delays. The capacitor at pin 7 can be omitted for low-cost applications. Field strength indicator output A buffered voltage source provides a high-level field strength output signal which has good linearity for logarithmic input signals over the whole dynamic range. If the field strength information is not needed, RL(11) can be omitted. Standby switch This switch is primarily intended for AM/FM band switching. During standby mode the oscillator, mixer and AF preamplifier are switched off. Short-circuit protection All pins have short-circuit protection to ground. December 1987 4 Philips Semiconductors Product specification AM receiver circuit TDA1572 RATINGS Limiting values in accordance with the Absolute Maximum Rating System (IEC 134) PARAMETER SYMBOL MIN. MAX. UNIT Supply voltage VP = V15-18 − 20 V Total power dissipation Ptot − 875 mW Input voltage V16-17 − 12 V −V16-18, −V17-18 − 0,6 V V16-18, V17-18 − VP V Input current I16, I18 − 200 mA Operating ambient temperature range Tamb −40 + 85 °C Storage temperature range Tstg −55 + 150 °C Junction temperature Tj − + 125 °C 80 K/W THERMAL RESISTANCE From junction to ambient December 1987 Rth j-a 5 Philips Semiconductors Product specification AM receiver circuit TDA1572 CHARACTERISTICS VP = V15-18 = 8,5 V; Tamb = 25 °C; fi = 1 MHz; fm = 400 Hz; m = 30%; fIF = 460 kHz; measured in test circuit of Fig.1; all voltages referenced to ground; unless otherwise specified. PARAMETER SYMBOL MIN. TYP. MAX. UNIT Supply Supply voltage (pin 15) VP 7,5 8,5 18,0 V Supply current (pin 15) IP 15 23 30 mA DC input voltage VI − VP/2 − V RF input impedance at V < 300 µV Zi − 5,5 − kΩ RF input capacitance Ci − 25 − pF RF input impedance at VI > 10 mV Zi − 8 − kΩ RF input capacitance Ci − 22 − pF IF output impedance (pin 1) Zo 200 − − kΩ IF output capacitance Co − 6 − pF I1/Vi − 6,5 − mA/V V1-15(p-p) − 5 − V IO − 1,2 − mA − 30 − dB Vi(rms) − 500 − mV Frequency range fosc 0,1 − 60 MHz Oscillator amplitude (pins 13 to 14) V − 130 150 mV External load impedance (pins 14 to 13) R(ext) 0,5 − 200 kΩ R(ext) − − 60 Ω RR − 55 − dB V − 4,2 − V −IO 0 − 20 mA ∆VI − 0,3 − V RF stage and mixer (pins 16 and 17) Conversion transconductance before start of AGC Maximum IF output voltage, inductive coupling to pin 1 (peak-to-peak value) DC value of output current; at VI = 0 V (pin 1) AGC range of input stage RF signal handling capability: (r.m.s. value): input voltage for THD = 3% at m = 80% Oscillator External load impedance for no oscillation (pins 14 to 13) Ripple rejection at VP(rms) = 100 mV; fp = 100 Hz (SVRR = 20 log [V15/V13]) Source voltage for switching diodes (6 × VBE) (pin 13) DC output current (for switching diodes) (pin 13) Change of output voltage at ∆l13 = 20 mA (switch to maximum load) (pin 13) December 1987 6 Philips Semiconductors Product specification AM receiver circuit TDA1572 PARAMETER SYMBOL MIN. TYP. MAX. UNIT Buffered oscillator output (pin 12) VO − 0,8 − V Vo(p-p) − 320 − mV Output impedance ZO − 170 − Ω Output current −IO(peak) − − 3 mA DC input voltage (pins 3 and 4) VI − 2,0 − V IF input impedance (pins 3 to 4) Zi 2,4 3,0 3,9 kΩ IF input capacitance Ci − 7 − pF DC output voltage Output signal amplitude (peak-to-peak value) IF, AGC and AF stages IF input voltage for Vi − 90 − mV Zo − 50 − Ω Vo 180 230 290 mV Gv − 68 − dB ∆Vv − 55 − dB AF output voltage at V3-4(IF) = 50 µV Vo(AF) − 130 − mV AF output voltage at V3-4(IF) = 1 mV Vo(AF) − 310 − mV AF output impedance (pin 6) Zo 2,8 3,5 4,2 kΩ Vo − − 140 mV RL = 2,7 kΩ Vo 2,5 2,8 3,1 V Load resistance RL 1,5 − − kΩ THD = 3% at m = 80% (pins 3 and 4) IF output impedance (pin 10) Unloaded IF output voltage at Vi = 10 mV (pin 10) Voltage gain before start of AGC (pins 3 to 4; 6 to 18) AGC range of IF stages: change of V3-4 for 1 dB change of Vo(AF); V3-4 (ref) = 75 mV Indicator driver (pin 11) Output voltage at Vi = 0 mV; RL = 2,7 kΩ Output voltage at Vi = 500 mV; Standby switch Switching threshold at; VP = 7,5 to 18 V Tamb = −40 to +80 °C ON-voltage V2-1 0 − 2,0 V OFF-voltage V2-1 3,5 − 20,0 V ON-current at V2-1 = 0 V −I2 − 100 200 µA OFF-current at V2-1 = 20 V I2 − − 10 µA December 1987 7 Philips Semiconductors Product specification AM receiver circuit TDA1572 OPERATING CHARACTERISTICS VP = 8,5 V; fi = 1 MHz; m = 30%; fm = 400 Hz; Tamb = 25 °C; measured in Fig.1; unless otherwise specified PARAMETER SYMBOL MIN. TYP. MAX. UNIT RF sensitivity RF input required for (S+N)/N = 6 dB Vi − 1,5 − µV RF input required for (S+N)/N = 26 dB Vi − 15 − µV RF input required for (S+N)/N = 46 dB Vi − 150 − µV RF input at start of AGC Vi − 30 − µV RF input at THD = 3%; m = 80% Vi − 500 − mV RF input at THD = 3%; m = 30% Vi − 700 − mV RF input at THD = 10%; m = 30% Vi − 900 − mV ∆Vi − 86 − dB ∆Vi − 91 − dB Vo(IF) 180 230 290 mV Vo(AF) − 130 − mV AF output voltage at Vi = 2 mV Vo(AF) 240 310 390 mV THD at Vi = 1 mV dtot − 0,5 − % THD at Vi = 500 mV dtot − 1 − % (S+N)/N − 58 − dB (SVRR = 20 log [VP/Vo(AF)]) RR − 38 − dB a) additional AF signal at IF output RR − 0* − dB (mref = 30%) RR − 40 − dB December 1987 8 RF large signal handling AGC range Change of Vi for 1 dB change of Vo(AF); Vi(ref) = 500 mV Change of Vi for 6 dB change of Vo(AF); Vi(ref) = 500 mV Output signal IF output voltage at Vi = 2 mV AF output voltage at Vi = 4 µV; m = 80% Signal plus noise-to-noise ratio at Vi = 100 mV Ripple rejection at Vi = 2 mV; VP(rms) = 100 mV; fp = 100 Hz b) add modulation at IF output Philips Semiconductors Product specification AM receiver circuit TDA1572 PARAMETER SYMBOL MIN. TYP. MAX. UNIT Unwanted signals Suppression of IF whistles at Vi = 15 µV; m = 0% related to AF signal of m = 30% at fi ≈ 2 × fIF α2IF − ** − dB at fi ≈ 3 × fIF α3IF − ** − dB for symmetrical input αIF − 40 − dB for asymmetrical input αIF − 40 − dB at fosc I1(osc) − 1 − µA at 2 × fosc I1(2osc) − 1,1 − µA IF suppression at RF input; Residual oscillator signal at mixer output; * AF signals at the IF output will be suppressed by a coupling capacitor to the demodulator and by full wave-detection in the demodulator. ** Value to be fixed. APPLICATION INFORMATION (1) Capacitor values depend on crystal type. (2) Coil data: 9 windings of 0,1 mm dia laminated Cu wire on TOKO coil set 7K 199CN; Qo = 80. Fig.2 Oscillator circuit using quartz crystal; centre frequency = 27 MHz. December 1987 9 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.4 Total harmonic distortion and (S + N)/N as functions of RF input in the circuit of Fig.1; m = 30% for (S + N)/N curve and m = 80% for THD curve. Fig.3 AF output as a function of RF input in the circuit of Fig.1; fi = 1 MHz; fm = 400 Hz; m = 30%. Fig.5 Total harmonic distortion as a function of modulation frequency at Vi = 5 mV; m = 80%; measured in the circuit of Fig.1 with C7-18(ext) = 0 µF and 2,2 µF. December 1987 10 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.7 Fig.6 Indicator driver voltage as a function of RF input in the circuit of Fig.1. Typical frequency response curves from Fig.1 showing the effect of filtering as follows: with IF filter; -- with AF filter; −−−−−− with IF and AF filters. Fig.8 Car radio application with inductive tuning. December 1987 11 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.9 AF output as a function of RF input using the circuit of Fig.8 with that of Fig.1. Fig.10 Suppression of cross-modulation as a function of input signal, measured in the circuit of Fig.8 with the input circuit as shown in Fig.11. Curve is for Wanted Vo(AF)/Unwanted Vo(AF) = 20 dB; Vrfw,Vrfu are signals at the aerial input, V’aew, V’aeu are signals at the unloaded output of the aerial. Wanted signal (V’aew, Vrfw): fi = 1 MHz; fm = 400 Hz; m = 30%. Unwanted signal (V’aeu, V’rfu): fi = 900 kHz; fm = 400 Hz; m = 30%. Effective selectivity of input tuned circuit = 21 dB. December 1987 12 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.11 Input circuit to show cross-modulation suppression (see Fig.10). Fig.12 Oscillator amplitude as a function of pin 13, 14 impedance in the circuit of Fig.8. December 1987 13 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.13 Total harmonic distortion and (S + N)/N as functions of RF input using the circuit of Fig.8 with that of Fig.1. Fig.14 Forward transfer impedance as a function of intermediate frequency for filters 1 to 4 shown in Fig.15; centre frequency = 455 kHz. December 1987 14 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.15 IF filter variants applied to the circuit of Fig.1. For filter data, refer to Table 1. December 1987 15 Philips Semiconductors Product specification AM receiver circuit TDA1572 Fig.16 IF output voltage as a function of RF input in the circuit of Fig.1; fi = 1 MHz. December 1987 16 December 1987 laminated wire 32 17 4,2 24 3 4,2 24 RG, RL Bandwidth (−3 dB) S9kHz 33 66 40 0,67 3,8 31 49 58 57 0,70 3,6 35 52 63 QB ZF Bandwidth (−3 dB) S9kHz S18kHz S27kHz 31 52 (L1) 7XNS-A7518DY 15 0,09 75 66 54 36 3,6 0,68 4,2 24 4,2 3 4 29 (N2) 29 7XNS-A7521AIH (N1) 60 0,08 29 : 29 4700 L2 18 (L2) SFZ455A 3 13 31 74 64 42 4,0 0,68 55 4,8 38 4,5 3 6 SFT455B 7XNS-A7519DY 75 0,09 13 : 31 3900 L1 4 dB dB dB kHz kΩ kΩ dB kHz kΩ dB mm pF UNIT AM receiver circuit * The beginning of an arrow indicates the beginning of a winding; N1 is always the inner winding, N2 the outer winding. 3,8 4,8 ZI 3 4 4 SFZ455A SFZ455A Filter data 13 L7PES-A0060BTG D (typical value) 7XNS-A7523DY 12 0,08 50 Murata type Resonators Toko order no. Schematic* of windings Qo 15 : 31 13 : (33 + 66) 0,09 12 : 32 N1: N2 L1 3900 2 430 L1 65 (typ.) 3900 Value of C Diameter of Cu L1 Coil data 1 Data for IF filters shown in Fig.15. Criteria for adjustment is ZF = maximum (optimum selectivity curve at centre frequency f0 = 455 kHz). See also Fig.14. FILTER NO. Table 1 Philips Semiconductors Product specification TDA1572 Philips Semiconductors Product specification AM receiver circuit TDA1572 PACKAGE OUTLINE DIP18: plastic dual in-line package; 18 leads (300 mil) SOT102-1 ME seating plane D A2 A A1 L c e Z w M b1 (e 1) b b2 MH 10 18 pin 1 index E 1 9 0 5 10 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT A max. A1 min. A2 max. b b1 b2 c D (1) E (1) e e1 L ME MH w Z (1) max. mm 4.7 0.51 3.7 1.40 1.14 0.53 0.38 1.40 1.14 0.32 0.23 21.8 21.4 6.48 6.20 2.54 7.62 3.9 3.4 8.25 7.80 9.5 8.3 0.254 0.85 inches 0.19 0.020 0.15 0.055 0.044 0.021 0.015 0.055 0.044 0.013 0.009 0.86 0.84 0.26 0.24 0.10 0.30 0.15 0.13 0.32 0.31 0.37 0.33 0.01 0.033 Note 1. Plastic or metal protrusions of 0.25 mm maximum per side are not included. OUTLINE VERSION REFERENCES IEC JEDEC EIAJ ISSUE DATE 93-10-14 95-01-23 SOT102-1 December 1987 EUROPEAN PROJECTION 18 Philips Semiconductors Product specification AM receiver circuit TDA1572 The device may be mounted up to the seating plane, but the temperature of the plastic body must not exceed the specified maximum storage temperature (Tstg max). If the printed-circuit board has been pre-heated, forced cooling may be necessary immediately after soldering to keep the temperature within the permissible limit. SOLDERING Introduction There is no soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and surface mounted components are mixed on one printed-circuit board. However, wave soldering is not always suitable for surface mounted ICs, or for printed-circuits with high population densities. In these situations reflow soldering is often used. Repairing soldered joints Apply a low voltage soldering iron (less than 24 V) to the lead(s) of the package, below the seating plane or not more than 2 mm above it. If the temperature of the soldering iron bit is less than 300 °C it may remain in contact for up to 10 seconds. If the bit temperature is between 300 and 400 °C, contact may be up to 5 seconds. This text gives a very brief insight to a complex technology. A more in-depth account of soldering ICs can be found in our “IC Package Databook” (order code 9398 652 90011). Soldering by dipping or by wave The maximum permissible temperature of the solder is 260 °C; solder at this temperature must not be in contact with the joint for more than 5 seconds. The total contact time of successive solder waves must not exceed 5 seconds. DEFINITIONS Data sheet status Objective specification This data sheet contains target or goal specifications for product development. Preliminary specification This data sheet contains preliminary data; supplementary data may be published later. Product specification This data sheet contains final product specifications. Limiting values Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information Where application information is given, it is advisory and does not form part of the specification. LIFE SUPPORT APPLICATIONS These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale. December 1987 19