Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 DESCRIPTION PT2579 is a Radio Data System Demodulator IC utilizing CMOS Technology specially designed for radio data system applications. The RDS data signal (RDDA) and the RDS clock signal (RDCL) are provided as outputs for further processing by an ideal decoder / microcontroller. Anti-aliasing Filter (2nd order), 57KHz band pass filter (8th order), reconstruction filter (2nd order), clocked comparator with automatic offset compensation, biphase symbol decoder, differential decoder, and signal quality detector are all built into a single chip having the highest performance and reliability. Pin assignments and application circuit are optimized for easy PCB layout and cost saving advantages. FEATURES • • • • • • • • • • • • • • • CMOS technology Low power consumption Anti-Aliasing filter (2nd Order) Reconstruction filter (2nd Order) 57KHz Band-Pass filet (8th Order) 57KHz carrier regeneration Differential decoder Signal quality detector Subcarrier output Selectable 4.332 / 8.664MHz Crystal Oscillator with variable dividers Synchronous demodulator for 57KHz Modulated RDS signals Clocked comparator with automatic offset compensation Clock generation with Lock on Biphase data rate Biphase symbol decoder with integrate and dump functions Available in 16 pins, DIP or SOP APPLICATIONS • Car radio • Home stereo tuner PT2579 V1.6 -1- May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 BLOCK DIAGRAM PT2579 V1.6 -2- May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 PIN CONFIGURATION Q UA L 1 16 RD CL RD DA 2 15 T5 7 VR EF 3 14 O S C2 MUX L 4 13 O S C1 AV DD 5 12 DV DD AV S S 6 11 DV S S C IN 7 10 TE S T S CO UT 8 9 PT2 57 9 MO D E PIN DESCRIPTION Pin Name QUAL RDDA VREF MUX AVDD AVSS CIN SCOUT MODE TEST DVSS DVDD OSC1 OSC2 T57 RDCL PT2579 V1.6 I/O O O I I O I I I O O O Description Quality indicator output pin RDS data output pin Reference voltage Multiplex signal input pin Analog supply voltage (+5V) Analog ground pin (0V) Subcarrier input pin to the comparator Reconstruction filter subcarrier output pin Oscillator mode / test control input pin Test pin Digital ground pin (0V) Digital supply voltage (+5V) Oscillator input pin Oscillator output pin 57KHz clock signal output pin RDS clock output pin -3- Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 FUNCTION DESCRIPTION PT2579 is a demodulator chip specially designed for radio data system applications. It provides 57KHz bandpass filter and a digital demodulator to regenerate the RDS data stream out of the multiplex signal (MPX). PT2579 consists of the Filter and Digital Sections. FILTER SECTION The MUX Signal is band limited by a second order anti-aliasing filter and fed through a 57KHz 8th order bandpass filter with a 3KHz bandwidth. This separates the RDS signals. This filter uses switch capacitor technique and uses a clock frequency of 541.5KHz which is derived from the 4.332/8.664 MHz crystal oscillator. The signal is then fed into the reconstruction filter to smooth the sampled and filtered RDS signal before it is outputted on the SCOUT pin. The signal is AC-coupled to the comparator pin (CIN). The comparator uses a frequency of 228KHz (synchronized by the 57KHz of the demodulator). DIGITAL SECTION The Costas Loop Circuit together with the carrier regeneration demodulates the internal coupled digitized signal. The suppressed carrier is recovered from the 2 sidebands (Costas Loop). The demodulated signal is low-pass filtered in such a way that the over all pulse shape (transmitter and receiver) approaches a cosinusoidal form in conjunction with the following integrate and dump circuit. The data spectrum shaping is divided into two equal parts and handled in the transmitter and in the receiver. Ideally, the data filtering should be equal in both of these parts. The overall data channel spectrum shaping of the transmitter and the receiver is approximately 100% roll off. Theintegrate and dump circuit performs anintegration over a clock period. This results in a demodulation and valid RDS signal in form of biphase symbols being outputted from the integrate and dump circuit. The final stages of the RDS data processing are the biphase symbol decoding and the differential decoding. After synchronization by the data clock RDCL, data appears on the RDDA output. The output of the biphase symbol decoder is evaluated by a special circuit to provide an indication of good data (QUAL=HIGH) or corrupt data (QUAL=LOW). PT2579 V1.6 -4- May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 TIMING The fixed and variable dividers are applied to the 4.332/8.664MHz crystal oscillator to generate the 1.1875KHz RDS Clock – RDCL. The RDCL is synchronized with the incoming data. No matter what clock edge is considered, the data will be valid for a period of 399 us after clock transition. The data change timing is 4µs before a clock change. Which clock transition (i.e. positive or negative going clock), the data change occurs in, depends on the lock conditions and is arbitrary (bit slip). When the reception is poor, it is possible that faults in phase occur, then the clock signal stays uninterrupted and data is constant for 1.5 clock periods. Normally, faults in phase do not occur in a cyclic manner. If however, the faults in the phase occur in this way, the minimum spacing between two possible faults in phase depends on the data being transmitted. The minimum spacing cannot be less than 16 clock period. The quality bit changes only at the time of a data change. The diagram below shows the RDS timing waveform which includes a phase jump. RDCL RDDA QUAL 4 µ s 842 µ s 421 µ s PT2579 V1.6 -5- 4µs May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 ABSOLUTE MAXIMUM RATING Parameter Analog supply voltage Digital supply voltage Voltage on all pins except GND Operating temperature Storage temperature PT2579 V1.6 Symbol AVDD DVDD Vn Topr Tstg -6- Condition AVDD DVDD Min. 0 0 -0.5 -40 -65 Max. 6 6 VDDX+0.5 +85 +150 Unit V V V ℃ ℃ May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 ELECTRICAL CHARACTERISTICS (Unless otherwise specified, AVDD=DVDD=5V, Ta=25℃) Parameter Symbol Conditions Analog supply AVDD AVDD voltage Digital supply DVDD DVDD voltage Total supply current Itot I5 + I12 Reference voltage Vref VREF, AVDD=5V MPX Input (Signal before the Capacitor on Pin 4) RDS amplitude f=+1.2KHz RDS ViMPX(rms) f=+3.5KHz ARI (see Note) (RMS value) f=57±2KHz Maximum input f<50KHz signal capability ViMPX(p-p) f<15KHz (peak to peak value) f>70KHz Input impedance R4-6 f=0 to 100KHz Signal gain G8-4 f=57KHz 57KHz Band-Pass Filter Ta=-40 to +85℃ Center frequency fc -3dB bandwidth B f=±7KHz f<45KHz Stop band gain G f<20KHz f>70KHz Output resistance Ro (8) f=57KHz (pin 8) Comparator Input (Pin 7) Minimum input level Vi(rms) f=57KHz (RMS value) Input resistance Ri Oscillator Input (Pin 13) High level input VIH DVDD=5.0V voltage Low level input DVDD=5.0V VIL Voltage Input current II DVDD=5.5V PT2579 V1.6 -7- Min. Typ. Max. Unit 3.3 5.0 5.5 V 3.3 5.0 5.5 V - 6 2.5 - mA V 1 - - mV 200 1.4 2.8 3.5 40 17 20 23 mV V V V KΩ dB 56.5 2.5 31 40 50 40 57.0 3.0 - 57.5 3.5 - KHz KHz dB dB dB dB - 26 - Ω - 1 10 mV 70 110 150 KΩ 4.0 - - V - - 1.0 V - - ±1 µA May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 Parameter Symbol Conditions Min. Typ. Max. Digital Demodulator and Outputs – QUAL, RDDA, T57, OSC2, RDCL High level output VOH IQ=-20µA, DVDD=4.5V 4.4 voltage Low level output VOL IQ=3.2mA, DVDD=5.5V 0.4 voltage Nominal clock fRDCL RDCL 1187.5 frequency RDCL jitter tRDCL 18 Nominal subcarrier T57 fT57 57.0 frequency (see Note 1) OSC2 1.5 DVDD=4.5V, V14=0.4V OSC2 -1.6 DVDD=4.5V, V14=4.1V Output current IO QUAL, RDDA, T57, RDCL 5.9 DVDD=4.5V, V14=0.4V QUAL, RDDA, T57, RDCL -5.3 DVDD=4.5V, V14=4.1V 4.332 MHz Crystal Parameter Crystal frequency f0 4.332 Maximum permitted fmax ±50 tolerance f0 adjustment Ta=25℃ ±20 f0 tolerance Ta=-40 to +85℃ ±25 Load capacitance CL 30 Resonance Rxtal 60 resistance 8.664 MHz Crystal Crystal frequency f0 8.664 Maximum permitted fmax ±50 tolerance Ta=25℃ ±30 f0 adjustment f0 tolerance Ta=-40 to +85 ℃ ±30 Load capacitance CL 30 Resonance Rxtal 60 resistance Note: The signal T57 has a phase lead of 123° (±180°) relative to ARI carrier at output SCOUT. PT2579 V1.6 -8- Unit V V Hz µs KHz mA mA mA mA MHz 10-6 10-6 10-6 pF Ω MHz 10-6 10-6 10-6 pF Ω May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 APPLICATION CIRCUIT 2.2 µ F + MUX SIGNAL 330pF 1 QUAL RDCL 16 2 RDDA T57 15 3 VREF OSC2 14 4 MUXL OSC1 13 5 AVDD DVDD 12 6 AVSS DVSS 11 7 CIN TEST 10 8 SCOUT 2.2KΩ +5V 0.1 µ F 560pF PT2579 MODE 4.332/8.664MHz +5V 82pF 47pF 0.1 µ F 9 Note: Two crystal frequencies may be used via the MODE pin. Please refer to the table below. For the 4.332MHz Crystal, it is recommended to use TXC 6A04300098 or a component with the same specifications. MODE Pin State LOW HIGH PT2579 V1.6 Crystal Clock Frequency (MHz) 4.332 8.664 -9- May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 ORDER INFORMATION Valid Part Number PT2579 PT2579-S PT2579-SN PT2579-X PT2579 V1.6 Package Type 16 pins, DIP, 300mil 16 pins, SOP, 300mil 16 pins, SOP, 150mil 16 pins, SSOP, 150mil - 10 - Top Code PT2579 PT2579-S PT2579-SN PT2579-X May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 PACKAGE INFORMATION 16 PINS, DIP, 300MIL PT2579 V1.6 - 11 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 Symbol A A1 A2 b b1 b2 b3 c c1 D D1 E E1 e eA eB eC L Min. 0.015 0.115 0.014 0.014 0.045 0.030 0.008 0.008 0.780 0.005 0.300 0.240 0.000 0.115 Nom. 0.130 0.018 0.018 0.060 0.039 0.010 0.010 0.790 0.310 0.250 0.100 bsc 0.300 bsc 0.130 Max. 0.210 0.195 0.022 0.020 0.070 0.045 0.014 0.011 0.800 0.325 0.280 0.430 0.060 0.150 Notes: 1. All dimensions are in INCHES. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimensions “A”, “A1” and “L” are measured with the package seated in JEDEC Seating Plane Gauge GS-3. 4. “D”, “D1” and “E1” dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch. 5. “E” and “eA” measured with the leads constrained to be perpendicular to datum -c-. “eB” and “eC” are measured at the lead tips with the loads unconstrained. 6. “N” is the number of terminal positions. (N=16) 7. Pointed or rounded lead tips are preferred to ease insertion. 8. “b2” and “b3” maximum dimensions are not include dambar protrusions. Dambar protrusions shall not exceed 0.010 inch (0.25 mm). 9. Distance between leads including Dambar protrusions to be 0.005 inch minimum. 10. Datum plane -H- coincident with the bottom of lead, where lead exits body. 11. Refer to JEDEC MS-001 Variation AB. JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2579 V1.6 - 12 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 16 PINS, SOP, 300MIL N H INDEX AREA .25 (.010) M B M E -B- 1 2 3 L -A- h X 45 SEATING PLANE A D -C∞ -e- C A1 .10 (.004) B .25 (.010) M C A M B S Symbol A A1 B C D E e H h L α PT2579 V1.6 Min. Max 2.35 2.65 0.10 0.30 0.33 0.51 0.23 0.32 10.10 10.50 7.40 7.60 1.27 BSC 10.00 10.65 0.25 0.75 0.40 1.27 0o 8o - 13 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 Notes: 1. Dimensioning and tolerancing per ANSI Y14.5M-1982. 2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold Flash, protrusion or gate burrs shall not exceed 0.15 mm (0.006 in) per side. 3. Dimension “E” does not include interlead flash or protrusions. Interlead flash or protrusions shall not exceed 0.25 mm (0.010 in) per side. 4. The chamfer on the body is optional. It is not present, a visual index feature must be located within the crosshatched area. 5. “L” is the length of the terminal for soldering to a substrate. 6. N is the number of the terminal positions (N=16) 7. The lead width “B” as measured 0.36 mm (0.014 in) or greater above the seating plane, shall not exceed a maximum value of 0.61 mm (0.24 in). 8. Controlling dimension : MILLIMETER. 9. Refer to JEDEC MS-013, Variation AA. JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2579 V1.6 - 14 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 16 PINS, SOP, 150MIL PT2579 V1.6 - 15 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 V1.6 PT2579 - 16 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC Symbol A A1 A2 b b1 c c1 D E E1 e L L1 L2 R R1 h θ θ1 θ2 PT2579 Min. 1.35 0.10 1.25 0.31 0.28 0.17 0.17 0.40 0.07 0.07 0.25 0° 5° 0° Typ. 9.90 BSC. 6.00 BSC. 3.90 BSC. 1.27 BSC. 1.04 REF. 0.25 BSC. - Max. 1.75 0.25 1.65 0.51 0.48 0.25 0.23 1.27 0.50 8° 15° - Note: 1. Dimensioning and tolerancing per ANSI Y 14.5M-1994 2. Controlling Dimension: MILLIMETERS. 3. Dimension D does not include mold flash protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15 mm (0.006 in) per end. Dimension E1 does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25mm per side. D and E1 dimensions are determined at datum H. 4. The package top may be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plastic body exclusive of mold flash, tie bar burrs, gate burrs and interlead flash, but including any mismatch between the top and bottom of the plastic body. 5. Datums A & B to be determined at datum H. 6. N is the number of terminal positions. (N=16) 7. The dimensions apply to the flat section of the lead between 0.10 to 0.25mm from the lead tip. 8. Dimension “b” does not include dambar protrusion. Allowable dambar protrusion shall be 0.10mm total in excess of the “b” dimension at maximum material condition. The dambar cannot be located on the lower radius of the foot. 9. This chamfer feature is optional. If it is not present, then a pin 1 identifier must be located within the index area indicated. 10. Refer to JEDEC MS-012, Variation AC. JEDEC is the registered trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2579 V1.6 - 17 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 16 PINS, SSOP, 150MIL PT2579 V1.6 - 18 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 V1.6 PT2579 - 19 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 V1.6 PT2579 Symbol A A1 A2 b b1 c c1 D E E1 e L L1 L2 R R1 Min. 0.053 0.004 0.049 0.008 0.008 0.006 0.006 Max. 0.069 0.010 0.065 0.012 0.011 0.010 0.009 0° Nom. 0.010 0.008 0.193 BSC 0.236 BSC 0.154 BSC 0.025 BAS 0.041 REF 0.010 BAS - θ θ1 5° - θ2 aaa bbb ccc ddd eee 0° - 15° - 0.016 0.003 0.003 0.050 8° 0.004 0.008 0.004 0.007 0.004 - 20 - May, 2008 Tel: 886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw RDS Demodulator IC PT2579 Notes: 1. Dimensioning and tolerancing per ANSI Y14.5M-1982. 2. Dimensions in inches (angles in degrees) 3. Dimension D does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.006” per end. Dimension E1 does not include interlead flash or protrusions. Interlead flash or protrusions shall not exceed “0.006” per side. D1 and E1 dimensions are determined at dutum H. 4. The package top may be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plastic body exclusive of mold flash, tie bar burrs, gate burrs and interlead flash, but including any mismatch between the top and bottom of the plastic. 5. Datums A and B to be determined at datum H. 6. N is the maximum number of terminal position. (N=16) 7. The dimensions apply to the flat section of the lead between 0.004 to 0.010 inches from the lead tip. 8. Dimension b does not include dambar protrusion. Allowable dambar protrusion shall be 0.004” total in excess of b dimension at maximum material condition. The dambar can not be located on the lower radius of the foot. 9. Refer to JEDEC MO-137 variation AB. JEDEC is the registered trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION PT2579 V1.6 - 21 - May, 2008