Q67000-A5144

Video and Sound IF with V & S SCART TDA 5940-2 Bipolar IC Features q q q q Features video / sound scart Active FM-PLL demodulator AF control Alignment - free sound IF P-DIP-24-2 Type TDA 5940-2 Ordering Code Q67000-A5144 Package P-DIP-24-2 Functional Description and Application Video IF Section Video IF-broadband amplifier followed by a quasi-synchronous demodulator for negative modulated IF signals. A Full-SCART interface is included in the video section. A separate video output after the demodulator permits the installation of one or more sound traps at the input of the SCART switch. The tuner AGC threshold is set by means of a potentiometer, all other functions can switched with open collector transistors. Sound IF Section FM-IF limiter with FM-PLL demodulator. The AF section has a Full-SCART switch followed by a volume control. The volume is controlled by an analog voltage. Application The TDA 5940-2 is suitable for application in television receivers with Full-SCART. Semiconductor Group 44 06.94 TDA 5940-2 Circuit Description Video IF Section The video IF section incorporates a four-stage, capacitively coupled, symmetrical and controlled amplifier, a limiter with selection and a mixer for quasi-synchronous demodulation of negative modulated IF signals followed by a video output amplifier. The video demodulator output and the SCART-switch input are connected by means of a sound trap. The SCART switch has two inputs (for signals from video demodulator and SCART socket) and two outputs (SCART socket and TV output). Parallel to the video output amplifier the video signal is used for generating the AGC voltage. The control circuit is designed on the integralaction AGC principle, employing a noise-free peak value detector. A delayed tuner AGC voltage with positive control direction is derived from the AGC -voltage via a threshold amplifier that is set by means of an external potentiometer. Sound IF Section The sound IF section incorporates a five-stage, symmetrical limiter amplifier followed by a PLL demodulator. The AF section contains an analog switch for the Full-SCART interface and a volume control with AF output. Semiconductor Group 45 TDA TDA 5940-2 Pin Functions Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Function Video IF input Video IF input Low-pass capacitor De-emphasis capacitor Audio SCART output Audio output Audio SCART input Audio volume control Sound IF input Ground Video demodulator output Video input at sound trap output Demodulator tank circuit Demodulator tank circuit MUTE control Video SCART input Video output Video SCART output + VS supply voltage Ground SCART control AGC-time constant Delayed tuner AGC threshold Delayed tuner AGC output Semiconductor Group 46 TDA 5940-2 Block Diagram Semiconductor Group 47 TDA 5940-2 Absolute Maximum Ratings TA = 0 to 85 ˚C Parameter Supply voltage Junction temperature Storage temperature Thermal resistance Operating Range Supply voltage Supply voltage delayed tuner AGC Ambient temperature during operation Input frequency range Symbol min. Limit Values max. 13.2 150 125 70 V ˚C ˚C K/W Unit VS Tj Tstg Rth JA VS V1 TA fIF 7.5 1 0 12 13.2 10 85 80 V V ˚C MHz Semiconductor Group 48 TDA 5940-2 Characteristics TA = 0 to 85 ˚C; VS = 12 V Parameter Total current SCART Switch H/open = SCART = Pb L = RF Volume Control Voltage Minimal volume Maximal volume MUTE Voltage H/open = AF ON L = AF MUTE Symbol min. Limit Values typ. 46 max. mA Unit Test Condition I19 V21 V21 2 0 5 1.5 V V V8 V8 0 3.6 5 V V V15 V15 2 0 5 1.5 V V Dynamic Parameter Video IF Section IF-input sensitivity Max. IF-input voltage IF-control range Video demodulator output voltage Gain of SCART Switch SCART/Video output Video/SCART output Video/Video output Cross talk attenuation V1/2 V1/2 ∆VIF 100 1.35 70 140 66 1.5 100 µV mV dB VVideo – 3 dB VVideo + 3 dB VIF IN = 10 mV V11pp 1.65 V G16-17 G12-18 G12-17 a 2 –1 2 50 dB fIN = 0 … 5 MHz Semiconductor Group 49 TDA 5940-2 Characteristics (cont’d) Parameter Symbol min. Sound IF Section Min. sound IF-input voltage (min. control) AF-output voltage Limit Values typ. max. Unit Test Condition V9 V6 500 70 µV mV ∆f = 30 kHz fmod = 1 kHz FSIF = 5.5 MHz ∆f = 30 kHz fmod = 1 kHz FSIF = 5.5 MHz ∆f = 30 kHz fmod = 1 kHz FSIF = 5.5 MHz SCART AF-output voltage V5 500 mV Total harmonic distortion THDAFo 0.5 % Max. SCART-input voltage Gain SCART-sound switch V7RMS G7-6 1 2 V V8 ≥ 3.6 V Alignment Instructions At a video carrier input level of V1/2 = 4 mVrms, fPC = 38.9 MHz, and a superimposed AGC voltage of V22 = 1.5 V, the demodulator tank circuit is preliminarily aligned until a max. video signal V11pp is obtained at the video output. Any suitable video test signal can be used for modulation. The AGC voltage V22 is reduced until the signal is approx. 1 Vpp and the max. video signal is obtained when fine-aligning the demodulator tank circuit. The alignment is not critical due to relatively large bandwidth of the demodulator tank circuit. Fine-tuning to intercarrier S/N, differential phase or 2T-pulse characteristics is possible. Semiconductor Group 50 TDA 5940-2 Test Circuit Semiconductor Group 51 TDA 5940-2 Application Circuit Semiconductor Group 52