U2514B AM/FM Receiver for Digital Tuning with FM-Stereo Decoder Description The U2514B is an integrated bipolar radio suitable for digital tuning systems. It contains a FM front end with pre-amplifier and FM-stereo decoder as well as a complete AM receiver and demodulator. Stop-signal generation is implemented for FM and AM mode. This circuit is designed for use in small radios, power packs and multimedia applications Features D High cut D FM wideband AGC D LO-buffer for digital tuning D Integrated stop signal generation with true D Mute function D Pilot canceller AM/ FM discriminators D Supply voltage range 3 to 12 V D Adjustable stop signal sensitivity D Automatic stereo-mono-blend D Package: SSO28 Block Diagram FMOSCE FMOSCB FMRF 6 5 AFSM FMDET 3 15 MPXOUT 11 MPXIN 25 24 28 FMIN 2 FM front end FMAGC 18 Matrix decoder + HCC FM IF + demodulator OUTR 19 OUTL 21 LPF 8 OSCOUT GNDRF 4 20 AM FM stop signal detect CERES Pilot PLL 23 CTRLB 27 1 AMIN AM IF + demodulator AM front end VS Control unit V Ref GND 16 7 10 12 AMOSC 13 METER FMIFIN IFOUT 17 AMIFIN 9 22 26 14 CTRLA AMSADJ AMFM VREF 12305 Figure 1. TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 1 (15) Preliminary Information U2514B Pin Description AMIN 1 28 FMIN FMAGC 2 27 VS FMRF 3 26 AMFM GNDRF 4 25 MPXOUT FMOSCE 5 24 MPXIN FMOSCB 6 23 CTRLB Pin 1 2 3 4 5 6 7 8 9 AMOSC 7 22 CTRLA OSCOUT 8 21 AMSADJ 9 20 CERES LPF IFOUT 10 19 OUTL AFSM 11 18 OUTR FMIFIN 12 17 METER AMIFIN 13 16 GND 15 FMDET VREF 14 10547 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Figure 2. Pinning 27 28 Symbol AMIN FMAGC FMRF GNDRF FMOSCE FMOSCB AMOSC OSCOUT Function AM antenna input FM-AGC time constant FM RF tank Ground RF FM oscillator emitter FM oscillator basis AM oscillator Buffered AM/FM oscillator output AMSADJ Current-input for AM stop signal adjust IFOUT AM/FM IF output AFSM AF smoothing voltage FMIFIN FM IF amplifier input AMIFIN AM IF amplifier input VREF Reference voltage FMDET FM discriminator output GND Ground METER Fieldstrength voltage output OUTR AF output right OUTL AF output left CERES Resonator 456 kHz LPF Low pass filter for Pilot-PLL CTRLA Control input for mute, search mode and search sensitivity CTRLB Control input for forced mono, control output for stop function and stereo information MPXIN Stereo decoder MPX input MPXOUT AM/FM MPX output AMFM AM/FM switch and pilot canceller time constant VS Supply voltage FMIN FM antenna input Ordering and Package Information Extended Type Number U2514B-AFN U2514B-AFNG3 Package SSO28 SSO28 Remarks Taping according to ICE-286-3 2 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B Pin Description FMIN, FMAGC, FMRF FMOSCE, FMOSCB FMOSCB 3 FMRF 6 VREF MIXER 1.2 k FMOSCE FMON 5 FMAGC T1 GNDRF T2 Figure 4. 2 I FMIN AGC 1.5 k FMON 28 GNDRF 12414 Figure 3. 12415 The FM local oscillator consists of a transistor in grounded collector configuration. The negative resistance at the base of the transistor is generated by an external capacitor connected between emitter FMOSCE (Pin 5) and GNDRF (Pin 4) An other external capacitor is connected between base FMOSCB (Pin 6) and emitter FMOSCE (Pin 5) which increases the resistance at the emitter and leads to a higher oscillator swing. The negative resistance at FMOSCB is approximately 250 W. Therefore, the resonant LO tank resistance of approximately 5 kW (depends on Q-factor of the coil) is transformed to this magnitude via a capacitor. OSCOUT 8 The FM pre-amplifier input FMIN (Pin 28) consists of a transistor grounded base circuit (T2) which provides excellent noise performance and large signal behavior. It is recommended to connect a source impedance of 100 W in order to achieve optimal performance. The dc current through the amplifying transitor is reduced by the internal AGC. This means in the case of large input signals, the input ac current is bypassed via the wideband AGC transistor T1. A capacitor is connected between FMAGC (Pin 2) and GNDRF (Pin 4). It shortens the transistor base to GNDRF and it also serves for smoothing of the AGC voltage. A tuned RF circuit is connected between FMRF (Pin 3) and VS (Pin 27). The amplified RF signal is fed internally to the mixer input. TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 OSCOUT FM AM 12416 Figure 5. A resistor is connected between OSCOUT (Pin 8) and VREF (Pin 14). It determines the amplitude of oscillator voltage which is fed to the PLL circuit. The TEMIC PLL familiy U428xBM is recommended because it offers high signal to noise ratio and low current consumption. 3 (15) Preliminary Information U2514B AMIN AMSADJ VREF 12418 9 AMSADJ AMIN 1 GND I AGC Figure 8. GNDRF 12417 Figure 6. The AM antenna coil is connected between AMIN (Pin 1) and VREF (Pin 14). In order to ensure that the AGC operates correctly, a coil impedance of approximately 25 kW is necessary. AMOSC 7 AMOSC The ceramic resonator of the stereo decoder PLL circuit is used as a stop signal detector for AM signals. For this purpose, the parallel resonance frequency of the resonator, which is unloaded about 456 kHz, is reduced by an internal load capacitor down to 455 kHz. Therefore, the AM IF must be 455 kHz. The internal loading capacitor is defined by the current through AMSADJ (Pin 9) to GND. An external resistor is connected between AMSADJ (Pin 9) and GND. It allows the alignment of the stop signal center frequency. The width of the stop window is typicaly 800 Hz. If AM searchmode is not activated, the pin is internally pulled to ground. VREF IFOUT 10 6k IFOUT AMON FM 12419 AM GNDRF 12420 Figure 7. Figure 9. The AM oscillator has to be loaded by an external tank referred to VREF (Pin 14). If reduction of the oscillator voltage is necessary, this may be achieved by a parallel resistor. The IF output (IFOUT Pin 10) of both the FM and the AM mixer has to be loaded into external IF-tank circuits refered to VREF (Pin 14). Q-factor of IF coils must not be lower than 50. 4 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B AMIFIN FMDET VREF VREF 3.3 k 15 13 FMDET AMIFIN 12421 150 mA 12422 Figure 10. Figure 12. The input impedance of the AM IF amplifier is 3.3 kW according to the required impedance of most ceramic filters. The input refers to VREF (Pin 14). The discriminator allows the connection of a ceramic resonator or LC tank. A minimization of THD and adjustment of center frequency versus temperature can only be achieved by using a LC tank. This performs a temperature independent stop signal. FMIFIN AFSM 25 MPXOUT 11 AFSM 40 mA 100 k 12 FMIFIN 12423 GND 12424 Figure 13. Figure 11. The input impedance of the FM IF amplifier is 330 W according to the required impedance of most FM ceramic filters. The input referes to GND (Pin 16). TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 A capacitor is connected between AFSM (Pin 11) and GND for smoothing of the FM-AF. This is necessary to generate a modulation independent stop signal. (Because the deviation of the FM signal (75 kHz) can be greater than the stop signal window (25 kHz)). In the AM-search-mode, the external capacitor smoothes the demodulated AM-IF-signal. 5 (15) Preliminary Information U2514B METER CTRLB VS 12425 VREF 30 k 23 1.2 V CTRLB FM AM 12447 17 GND METER Figure 16. Figure 14. This pin is driven by a current corresponding to the level of the FM or AM-IF-signal. The required external load consists of a resistor (100 to 150 kW) in parallel with an external capacitor (e.g., 10 mF necessary to achieve a good THD in AM mode and to supress AF influence in FM mode). The voltage at this pin controls the high cut and mono/ stereo blend function in the case of reception mode. These functions can be affected by the designer by choosing different values of the load resistor. The signal at the output CTRLB (Pin 23) shows stereo or mono reception. The stereo reception is indicated if the voltage is higher than 1.2 V, otherwise it is mono. Furthermore there is the possibility to force the receiver circuit to mono by applying an external control voltage <0.8 V at CTRLB. If the search mode is selected, the low active stop signal appears at CTRLB. If the output CTRLB is connected directly to the I/O-port of the microcontroller, the high level of CTRLB has to be adapted by connecting a resistor between CTRLB and GND. VREF A internal voltage regulator generates a stable reference voltage of 2.4 V which is needed for all function blocks of the IC. An external capacitor has to be connected to GND in order to achieve stability and noise suppression. CTRLA AMFM 22 CTRLA GND 12448 26 AMFM Figure 15. 12454 The reception mode, search mode, as well as mute function and search sensitivity can be selected by applying a control voltage at CTRLA (Pin 22). If the control voltage is higher than 0.8 V, the receiver circuit is in the reception mode, otherwise it is in search mode. When reducing the control voltage between 1.3 and 0.8 V, the AF level output at OUTR, OUTL (Pin 18, 19) is reduced (mute function). In the search mode (0.7 to 0 V), the voltage size determines the degree of the search sensitivity. Figure 17. By applying a low voltage (<1.1 V) at AMFM (Pin 26), the receiver circuit is switched to AM mode. If Pin AMFM is open, the FM mode is selected. This switching function can easily be performed by a microcontroller with “open drain” I/O-ports. A capacitor has to be connected between AMFM and GND for FM mode operation. It serves for smoothing the control voltage of the pilot canceller. 6 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B CERES MPXIN 24 VREF 20 10 k MPXIN 60 k 12452 CERES 50 k GND Figure 20. 12449 The MPX signal is applied to MPXIN (Pin 24). It is fed to the stereo decoder. The input resistance into Pin 24 is approximately 10 kW. It is recommended to align the channel separation by an RC network between MPXIN and MPXOUT (Pin 25) due to the tolerances in group delay of the IF filter. MPXOUT Figure 18. VREF A ceramic resonator of 456 kHz parallel resonance frequency (at 30 pF chip internal load capacitance) is connected between CRES (Pin 20) and GND (necessary for the pilot regeneration). It should be mounted very close to Pin 20 in order to avoid spurios radiation. In the AM (V26 < 1.1 V) search (V22 < 0.8 V) mode, the resonator is used for stop signal generation. The parallel resonance frequency is then reduced down to 455 kHz by adjusting the current into Pin 9 AMSADJ. 25 MPXOUT GND 12451 Figure 21. LPF 25 k VREF In order to drive both the compensation network to MPXIN (Pin 24) and an optional RDS decoder, the MPXOUT (Pin 25) has a low output impedance. The dc level is 1.2 V in FM mode (depending on the discriminator coil alignment) and 0.7 to 1.5 V in AM mode (depending on the signal level). OUTR/OUTL 21 VREF LPF 18,19 12450 OUTL OUTR 12453 Figure 19. Figure 22. A PLL circuit is used for the pilot regeneration of the stereo decoder. Therefore, a loopfilter consisting of an RC network is connected between LPF (Pin 21) and GND. The open collector output of OUTR/OUTL (Pin 18/19) requires an external resistor of about 4.7 kW to ground. The de-emphasis may be achieved by an additional parallel capacitor. TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 7 (15) Preliminary Information U2514B Functional Description Search Mode FM The search-mode is selected by applying a control voltage less than 0.7 V at pin CTRLA. A tuned RF circuit on the collector is necessary for amplifying and filtering of the FM signal which is fed internally to the mixer. It consists of a double balanced Gilbert Cell. The LO signal is generated by an integrated oscillator. The buffered LO signal is used to drive a PLL. The IF-signal (10.7 MHz) is coupled out at the mixers output and fed via a ceramic filter to the demodulator. The demodulated AF signal is available at MPXOUT. 50 40 VANT ( dB m V ) The antenna signal is fed via a tuned RF-circuit to the integrated pre-stage which consists of a transistor grounded base circuit. To protect the prestage against overload, an automatic gain control (AGC) is included on the chip. Additional there is the possibility to extend the AGC control range by use of an external pin diode. For economic applications a hybrid-band pass filter can be used instead of a tuned RF-circuit. 30 20 10 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 VCTRLA ( V ) 12591 AM Figure 24. The antenna signal is fed directly to the mixer. In order to ensure the level control which is necessary in the case of large signals, the generator resistance has to be higher than 25 kW. The LO signal is generated by an integrated oscillator. The buffered LO signal is used to drive the PLL. If the AM-search mode is required, the IF must be 455 kHz. The IF output signal is fed via a ceramic filter to the demodulator. The demodulated AF signal is available at MPXOUT. CTRLA The search sensitivity can be chosen by varying of the control voltage in the range of 0 to 0.7 V. If the control voltage is 0 V, the highest sensitivity is achieved. Reception Mode In the reception-mode there is a possibility for muting by varying the control voltage in the range of 1.3 to 0.8 V. If the control voltage is 0.8 V, the highest mute depth is achieved. By applying a control voltage at pin CTRLA the mode of the receiver can be selected. 10 0 12593 VOUTL, OUTR ( dB ) Mode Reception –10 –20 –30 –40 Mute –50 Search VCTRLA 0.8 V 1.3 V 0 0.4 12690 0.8 1.2 1.6 2.0 VCTRLA ( V ) VRef Figure 23. Figure 25. 8 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B CTRLB The output CTRLB indicates whether the receiver is working in mono or stereo mode. 12594 Mode If a control voltage less than 0.8 V is applied at CTRLB, the receiver is forced to mono. 12592 VCTRLB VS Stereo t STOP Mono Figure 27. VCTRLB VS 1.2 V Figure 26. In the search mode (VCTRLA < 0.7 V), the internally generated stop signal is available at CTRLB as low active signal. Absolute Maximum Values Reference point Pin 16 and 4, unless otherwise specified Parameters Symbol VS P ILoad Tj Tstg Tamb ±VESD Supply voltage Power dissipation External reference current to GND Junction temperature Storage temperature Ambient temperature Electrostatic handling Value 12 750 3 125 25 to 125 30 to 85 2000 * * ) ) ) Unit V mW mA °C °C °C V Thermal Resistance Parameters Junction ambient when soldered to PCB TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 Symbol RthJA Value tbd. Unit K/W 9 (15) Preliminary Information U2514B Electrical Characteristics VS = 9 V, Tamb = 25°C; reference point Pins 4 or 16, unless otherwise specified Parameters DC supply Supply voltage range Supply current Reference voltage CTRLA Input voltage Search mode Reception mode Mute function CTRLB Output voltage Mono Stereo Stop signal High Low Stop window (FM) Stop window (AM) Input voltage Forced mono AMFM Input voltage AM FM OSCOUT Output voltage AM FM DC-current (FM) METER Starting point meter (FM) Slope of meter (FM) Usable meter range (FM) DC-output voltage (AM) Test Conditions / Pins Symbol Min. Pin 27 Pin 27 Pin 14 VS IS VRef 3.0 Pin 22 VCTRLA Reception mode VCTRLA > 0.8 V Pin 23 VCTRLB Search mode VCTRLA < 0.8 V VCTRLB fcenter = 455 kHz adjusted at AMSADJ Max. Unit 12.0 2.5 V mA V 0 0.8 0.8 0.7 VRef 1.3 V V V 0 1.2 1.2 VS V V 1.5 0 VS 0.6 V V kHz kHz 2.3 f f VCTRLB Typ. 8 2.4 20 1 0 0.8 V Pin 26 VAMFM 0 1.1 V open Pin 8 VOSCOUT fLO = 110 MHz, unloaded IOSCOUT Pin 17 Pin 17 Pin 17 See AM test circuit, Pin 17 VRF = 0 dBmV VRF = 40 dBmV VRF = 100 dBmV R17 = 150 kW vstart vslope 120 150 0.7 mVrms mVrms mA 5 0.04 48 mV V/dB dB 0.05 0.7 1.8 V V V VMETER 10 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B Parameters MPXOUT Output voltage (AM) Total distortion Signal plus noise-to-noise Sensitivity (AM) Sensitivity (FM) MPXIN Input resistance Input voltage OUTL, OUTR AF output voltage Test Conditions / Pins Symbol Min. Typ. Max. See AM test circuit fRF =1 MHz, m = 0.3,fmod = 1 kHz, Rgen = 25 kW, VCTRLA = 1.7 V, VRF = 20 dBmV VMPXOUT 35 VRF = 40 dBmV 54 VRF = 100 dBmV 66 VRF = 100 dBmV d 0.7 VRF = 40 dBmV (S+N)/N 27 VRF = 100 dBmV 47 (S+N)/N = 26 dB 38 f0 = 98 MHz, 4 deviation = ±75 kHz, without de-emphasis (S+N)/N = 26 dB Pin 24 Unit Pin 25 mVrms mVrms mVrms % dB dB dBmV mV kW mVpp RMPXIN VMPXIN 10 VOUT 110 Iout aM a a19kHz 15 40 26 28 fCERES 456 kHz Pin 3 See FM test circuit 20 log (vFMRF/v0) 3 dB compression at Pin 3 IFMRF gFMRF 1 16 mA dB v0AGC 5 mV Pin 10 log (vIFOUT/vFMRF) IIFOUT gc 0.4 20 mA dB rFMIFIN 330 W Df = ±75 kHz, 900 mVrms fmod = 1 kHz, VFMIN = 1 mV, fFMIN = 97 MHz Pin 18/19 Output current Muting attenuation Channel separation Pilot signal suppression CERES PLL oscillator frequency Df = ±75 kHz, mA dB dB dB fmod = 1 kHz, Pilot Df = ±6.7 kHz VFMIN = 1 mV, fFMIN = 97 MHz Pin 20 FMRF DC-current Voltage gain preamplifier AGC threshold IFOUT DC-current Conversion gain FMIFIN Input resistance 20 TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 Pin 12 11 (15) Preliminary Information VTUNE AM 12612 R1 12 (15) Preliminary Information 56k W R 13 15nF 15pF C2 10pF C T1 CD1 KV1551A1 2 6 L8 4 C3 GND 560k W R2 BB814 1 2 3 L1 C4 R 14 100k W R 17 10k W R 15 BB814 CD3 56k W 1 28 2 2 1 3 C 19 430pF CD5 2.2nF C 20 2.2nF C 18 27 100nF 100nF 10 m F 3 R 16 C T2 C 31 15pF 1 1 2 3 6 C 23 3.9k W R3 Q1 4 L5 6 C 32 3.9pF 10pF 23 1 L4 22pF 3 BC237 C 22 2 5 24 CD4 BB814 3 10pF C 21 15pF 4 25 56k W L3 C 24 1 3 26 50k W R P1 100 pF C8 21 7 470 W R 18 8 9 C 12 100 pF 100 pF 100k W R P3 10k W R 19 456kHz 10nF 20 100nF C 11 CSB 456 F10 R5 150k W U2514B 22 CTRLA 3 1 ANT CD8 2.2nF 100nF AM FM 10nF C 10 10 19 R6 3 2 1 1 2 3 100nF C 28 5.1k W 10nF 11 18 4 L7 6 6 L6 4 1 mF C 14 5.1k W R7 10.7MHz 12 17 R8 150k W METER 56k W VTUNE FM C7 GND C5 VS C 13 OUTR C6 AM/FM S3 MPXOUT C 30 CTRLB LED1 13 16 C 25 14 15 C 17 10nF 100nF C 29 100pF C 16 R 12 100 W 100 m F 6.8k W R 11 L2 455kHz 3 1 4.7nF C 15 R 10 VREF 3.9pF C1 S1 OUTL 470nF 5.6k W U2514B OSCOUT GND Figure 28. Application circuit TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 VTUNE AM TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 12612 VTUNE FM Preliminary Information 56k W R 13 15nF 15pF C2 10pF C3 GND C T1 CD1 KV1551A1 MB&L L1 R 14 100k W R 17 10k W R 15 BB814 CD3 56k W 1 28 2 1 3 C 19 430pF CD5 2.2nF C 20 2.2nF C 18 100nF 2 27 3 R 16 C T2 C 31 15pF 1 3 1 2 3 6 C 23 3.9k W R3 Q1 4 L5 6 C 32 3.9pF 10pF 23 1 L4 22pF C 22 2 5 24 CD4 BB814 3 10pF C 21 15pF 4 25 56k W L3 C 24 1 3 26 BC237 21 7 470 W R 18 8 9 C 12 100 pF 100 pF 100k W R P3 10k W R 19 456kHz 10nF 20 100nF C 11 CSB 456 F10 R5 150k W U2514B 22 CTRLA 560k W R2 ANT 50k W R P1 100 pF 10nF C 10 10 19 R6 3 2 1 1 2 3 100nF C 28 5.1k W 10nF 11 18 4 L7 6 6 L6 4 1 mF C 14 5.1k W R7 10.7MHz 12 17 R8 150k W METER BPF 100nF 10 m F 100nF C8 LED1 GND C5 VS C7 OUTR C6 AM/FM C 13 13 16 C 25 14 15 C 17 10nF 100nF C 29 100pF C 16 R 12 100 W 100 m F 6.8k W R 11 L2 455kHz 3 1 4.7nF C 15 R 10 VREF AM FM MPXOUT S3 CTRLB C 30 S1 OUTL 470nF 5.6k W U2514B OSCOUT GND Figure 29. Application circuit (upgraded) 13 (15) U2514B Dimensions in mm Package: SSO28 9.25 8.75 7.5 7.3 12.7 12.9 2.35 0.25 0.30 0.80 10.4 0.25 0.10 10.50 10.20 technical drawings according to DIN specifications 1 14 (15) Preliminary Information TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 U2514B Ozone Depleting Substances Policy Statement It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances ( ODSs). The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency ( EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively. TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423 TELEFUNKEN Semiconductors Rev. A2, 04-Nov-96 15 (15) Preliminary Information