 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| TDA7479 SINGLE CHIP RDS DEMODULATOR + FILTER VERY HIGH RDS DEMODULATION QUALITY WITH IMPROVED DIGITAL SIGNAL PROCESSING HIGH PERFORMANCE, 57KHz BANDPASS FILTER (8th ORDER) FILTER ADJUSTMENT FREE AND WITHOUT EXTERNAL COMPONENTS PURELY DIGITAL RDS DEMODULATION WITHOUT EXTERNAL COMPONENTS ARI (SK INDICATION) AND RDS SIGNAL QUALITY OUTPUT 4.332MHz CRYSTAL OSCILLATOR (8.664 and 17.328MHz OPTIONAL) LOW NOISE CMOS TECHNOLOGY LOW RADIATION DESCRIPTION The TDA7479 recovers the additional inaudible RDS information which is transmitted by FM radio broadcasting stations and operates in accordance with the EBU (European Broadcasting Union) specifications. BLOCK DIAGRAM AND TEST CIRCUIT DIP16 SO16 ORDERING NUMBERS: TDA7479 TDA7479D The device is made up of two sections: a cascaded antialiasing + switched capacitors bandpass filter for precise RDS band selection and a demodulating section that performs the extraction od RDS data stream (RDDA) and clock (RDCL), to be furher processed by a suitable RDS decoder. Outputs for RDS signal quality and ARI indication are also present. C1 27pF 4.332MHz C2 47pF T57 15 4 270pF 2nd ORDER ANTIALIASING FILTER OSCIN 13 OSCOUT 14 MPX 5 OSCILLATOR & DIVIDER 9 OSEL FSEL 16 FILOUT 8 8th ORDER SC-BANDPASS FILTER 57KHz PLL 1187.5Hz PLL 7 1 VS 100nF VREF 10F INTEGRAL BIPHASE DEC. 3 + POLARITY BIPHASE DEC. 0 1 10 TEST LOGIC 2 12 FAST ARI INDICATOR QUAL DET. RDCL ARI QUAL MUX DIFF. DECODER RDDA TM 6 GND 11 EXTRES D97AU751A February 1998 1/7 TDA7479 ABSOLUTE MAXIMUM RATINGS Symbol VS Top Tstg Parameter Supply Voltage Operating Temperature Range Storage Temperature Value -0.3 to 7 -40 to 85 -55 to 150 Unit V C C THERMAL DATA Symbol Rth j-case Description Thermal Resistance Junction-case Max. DIP16 100 SO16 200 Unit C/W PIN DESCRIPTION N o pin 1 2 3 4 5 6 7 Name QUAL RDDA VREF MPX OSEL GND ARI Description Output for signal quality indication (High = good) RDS data output Reference voltage RDS input signal Oscillator selector pin: - open, closed to VS = quartz oscillator - closed to GND=external driven Ground Output for ARI indication: - high when RDS+ARI are present - high when only ARI is present - low when only RDS is present - undefined when nos signal is present Filter output Frequency selector pin: -100K to VS = 17.328MHz - open = 4.332MHz - closed to V S = 8.664MHz Test mode pin: - open = normal operation - closed to V S = testmode Reset pin: - open=run mode - closed to V S = reset condition Supply voltage Oscillator input Oscillator output Testing output pin: 57kHz clock output RDS clock output 1187.5Hz 8 9 FILOUT FSEL 10 11 12 13 14 15 16 TM EXTRES VS OSCIN OSCOUT T57 RDCL PIN CONNECTION (Top View) QUAL RDDA VREF MPX OSEL GND ARI FILOUT 1 2 3 4 5 6 7 8 D97AU752 16 15 14 13 12 11 10 9 RDCL T57 OSCOUT OSCIN VS EXTRES TM FSEL 2/7 TDA7479 THERMAL DATA Symbol Rth j-amb Description Thermal Resistance Junction-Ambient Max DIP20 100 SO20 200 Unit C/W ELECTRICAL CHARACTERISTICS (Tamb = 25C, VS = 5V, unless otherwise specified). Symbol VS IS Parameter Supply voltage Supply current Test Condition Min. 4.5 Typ. 5 7.5 Max. 5.5 11.0 Unit V mA FILTER fC BW G A Center frequency 3dB Bandwidth Gain Attenuation f = 57kHz f 4kHz f = 38kHz f = 67kHz RI RL S/N VIN VREF Input impedance of MPX Load impedance on FILOUT Signal to noise ratio MPX input signal Reference VIN = 3mVRMS f = 19kHz; T3 40dB(1) f = 57kHz (RDS+ ARI) VS/2 56.5 2.5 18 18 50 35 80 1 30 40 1000 50 57 3 20 22 60 45 120 150 57.5 3.5 22 kHz kHz dB dB dB dB K M dB mVRMS mVRMS V DEMODULATOR Input pins (EXTRES, FSEL, TM) Input pin (OSEL) IPD IPU VIH V IL VOH V OL Input Current Input Current Input voltage high Input voltage low Ouput voltage high Output voltage low IL = 0.5mA IL = 0.5mA 4 VIN = 5V (pull-down input) VIN = 0V (pull-up input) all with internal pull down resistor with internal pull up resistor 15 -25 0.7 VS 0.8 VS 0.2 VS 0.3 VS 4.6 0.4 1 30 -10 A A V V V V Output pins (RDCL, RDDA, ARI, QUAL, T57) OSCILLATOR VCLL VCLH V PP Input level OSCIN pin Input level OSCIN pin Amplitude OSCOUT Amplitude OSCIN (for external drive) OSEL = open circuit OSEL = open circuit OSEL = open circuit OSEL = GND, f = 4.332MHz OSEL = GND, f = 8.664MHz OSEL = GND, f = 17.328MHz (1) The 3rd harmonic (57kHz) must be less than -40dB with respect to the input signal plus gain. 1 4 4.5 100 120 150 V V V mVpp mVpp mVpp 3/7 TDA7479 Figure 1. RDS timing diagram CLOCK LINE DATA LINE OUTPUT TIMING The RDS (1187.5Hz) output clock on RDCL line is synchronized to the incoming data. According to the internal PLL lock condition data change can result on the falling or on the rising clock edge. (see Fig. 1) Whichever clock edge is used by the decoder (rising or falling edge) the data will remain valid for 416.7 sec after the clock transition. OSCILLATOR CONTROLS (FSEL, OSEL) Three different crystal frequencies can be used. The adaption of the internal clock divider to the external crystal is achieved via the input pin FSEL. See the following table for reference: Crystal 4.332MHz 8.664MHz 17.328MHz FSEL (pin configuration) connected to GND or open connected to Vs external resistor of 100K to Vs A special mode is introduced to reduce EMI. With pin OSEL connected to GND the internal oscillator is switched off and an external sinusoidal frequency could be applied on OSCIN. The peak to peak voltage of this signal can be reduced down to 60mV. In this mode the frequency selection via FSEL is still active. Suggested values of C1 and C2 are shown in the following table: Crystal 4.332MHz 8.664MHz 17.328MHz C1 27pF 27pF 27pF C2 47pF - 4/7 TDA7479 DIP16 PACKAGE MECHANICAL DATA DIM. MIN. a1 B b b1 D E e e3 F I L Z 3.3 1.27 8.5 2.54 17.78 7.1 5.1 0.130 0.050 0.51 0.77 0.5 0.25 20 0.335 0.100 0.700 0.280 0.201 1.65 mm TYP. MAX. MIN. 0.020 0.030 0.020 0.010 0.787 0.065 inch TYP. MAX. 5/7 TDA7479 SO16 PACKAGE MECHANICAL DATA DIM. MIN. A a1 a2 b b1 C c1 D E e e3 F L M S 7.4 0.5 10.1 10.0 1.27 8.89 7.6 1.27 0.75 8 (max.) 0.291 0.020 10.5 10.65 0.35 0.23 0.5 45 (typ.) 0.398 0.394 0.050 0.350 0.299 0.050 0.030 0.413 0.419 0.1 mm TYP. MAX. 2.65 0.3 2.45 0.49 0.32 0.014 0.009 0.020 0.004 MIN. inch TYP. MAX. 0.104 0.012 0.096 0.019 0.013 6/7 TDA7479 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. Specification 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. (c) 1998 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. 7/7 |
Price & Availability of TDA7479D
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |