RF COMMUNICATIONS PRODUCTS SA617 Low-voltage high performance mixer FM IF system Product specification Replaces data of November 3, 1992 IC17 Data Handbook Philips Semiconductors 1997 Nov 07 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system DESCRIPTION SA617 PIN CONFIGURATION The SA617 is a low voltage high performance monolithic FM IF system incorporating a mixer/oscillator, two limiting intermediate frequency amplifiers, quadrature detector, logarithmic received signal strength indicator (RSSI), voltage regulator and audio and RSSI op amps. The SA617 is available in 20-lead SSOP package. DK Package The SA617 was designed for portable communication applications and will function down to 2.7V. The RF section is similar to the famous SA605. The audio output has an internal amplifier with the feedback pin accessible. The RSSI output is buffered. The SA617 also has an extra limiter output. This signal is buffered from the output of the limiter and can be used to perform frequency check. This is accomplished by comparing a reference frequency with the frequency check signal using a comparator to a varactor or PLL at the oscillator inputs. RF IN+ 1 20 MIXER OUT RF IN– DECOUPLING 2 19 IF AMP DECOUPLING OSCOUT 3 18 IF AMP IN OSCIN 4 17 IF AMP DECOUPLING RSSI OUT 5 16 IF AMP OUT VCC 6 15 GND 7 14 LIMITER IN AUDIO FEEDBACK AUDIO OUT 8 13 LIMITER DECOUPLING FREQ CHECK/LIM OUT (–) 9 12 LIMITER DECOUPLING 11 QUADRATURE IN 10 FEATURES • Low power consumption: 3.5mA typical at 3V • Mixer input to >150MHz • Mixer conversion power gain of 17dB at 45MHz • XTAL oscillator effective to 150MHz (L.C. oscillator or external LIM OUT (+) SR00405 Figure 1. Pin Configuration • Internal op amps with rail-to-rail outputs • ESD protection: Human Body Model 2kV oscillator can be used at higher frequencies) Robot Model 200V • 102dB of IF Amp/Limiter gain • 2MHz IF amp/limiter small signal bandwidth • Temperature compensated logarithmic Received Signal Strength APPLICATIONS • Portable cellular radio FM IF • Cordless phones • Narrow band cellular applications (NAMPS/NTACS) • RF level meter • Spectrum analyzer • Instrumentation • FSK and ASK data receivers • Log amps • Portable high performance communication receivers • Single conversion VHF receivers • Wireless systems Indicator (RSSI) with a 80dB dynamic range • Low external component count; suitable for crystal/ceramic/LC filters • Excellent sensitivity: 0.31µV into 50Ω matching network for 12dB SINAD (Signal to Noise and Distortion ratio) for 1kHz tone, 8kHz deviation with RF at 45MHz and IF at 455kHz • SA617 meets cellular radio specifications • Audio output internal op amp • RSSI output internal op amp • Buffered frequency check output ORDERING INFORMATION DESCRIPTION 20-Pin Plastic Shrink Small Outline Package (SSOP) (Surface-mount) 1997 Nov 07 2 TEMPERATURE RANGE ORDER CODE DWG # -40 to +85°C SA617DK SOT266-1 853-1678 18665 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 BLOCK DIAGRAM 20 19 18 17 16 15 14 IF AMP 13 12 11 9 10 LIMITER RSSI MIXER QUAD OSCILLATOR – – + + VREG 1 2 E B 3 4 AUDIO 5 6 7 8 SR00406 Figure 2. Block Diagram ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER VCC Single supply voltage TSTG RATING UNITS 7 V Storage temperature range –65 to +150 °C TA Operating ambient temperature range SA617 –40 to +85 °C θJA Thermal impedance 117 °C/W DK package DC ELECTRICAL CHARACTERISTICS VCC = +3V, TA = 25°C; unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS SA617 MIN VCC Power supply voltage range ICC DC current drain 1997 Nov 07 TYP 2.7 3.5 3 UNITS MAX 7.0 V 5.0 mA Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 AC ELECTRICAL CHARACTERISTICS TA = 25°C; VCC = +3V, unless otherwise stated. RF frequency = 45MHz + 14.5dBV RF input step-up; IF frequency = 455kHz; R17 = 2.4k; R18 = 3.3k; RF level = –45dBm; FM modulation = 1kHz with ±8kHz peak deviation. Audio output with de-emphasis filter and C-message weighted filter. Test circuit NO TAG. The parameters listed below are tested using automatic test equipment to assure consistent electrical characterristics. The limits do not represent the ultimate performance limits of the device. Use of an optimized RF layout will improve many of the listed parameters. LIMITS SYMBOL PARAMETER TEST CONDITIONS SA617 MIN TYP UNITS MAX Mixer/Osc section (ext LO = 220mVRMS) fIN fOSC Input signal frequency 150 MHz Crystal oscillator frequency 150 MHz Noise figure at 45MHz 6.8 dB –9 dBm 17 dB +2.5 dB Third–order input intercept point (50Ω source) f1 = 45.0; f2 = 45.06MHz Input RF Level = –52dBm Conversion power gain Matched 14.5dBV step–up 11.0 50Ω source RF input resistance Single–ended input 8 RF input capacitance 3.0 Mixer output resistance (Pin 20) IF amp gain Limiter gain Input limiting –3dB, R17 = 2.4k 1.25 kΩ 4.0 pF 1.5 kΩ 50Ω source 44 dB 50Ω source 58 dB Test at Pin 18 –105 dBm AM rejection 80% AM 1kHz 40 dB Audio level Gain of two (2kΩ AC load) 114 mV SINAD sensitivity RF level –110dB 13 dB –45 dB IF section 60 THD Total harmonic distortion –30 S/N Signal–to–noise ratio No modulation for noise 62 IF RSSI output, R9 = 2kΩ1 IF level = –118dBm 0.3 0.8 V V IF level = –68dBm .70 1.1 2.0 IF level = –23dBm 1.0 1.8 2.5 RSSI range RSSI accuracy IF input impedance 1.3 IF output impedance Limiter input impedance Limiter output impedance Limiter output level dB 1.30 (Pin 11) (Pin 11) No load 2.4kΩ load V 80 dB +2.0 dB 1.5 kΩ 0.3 kΩ 1.5 kΩ 200 Ω 130 115 mVRMS 200 Ω No load 2.4kΩ load 130 115 mVRMS Audio level 3V = VCC, RF level = –27dBm 240 mVRMS System RSSI output 3V = VCC, RF level = –27dBm 2.2 V System SINAD sensitivity RF level = –117dBm 12 dB Frequency Check/limiter output impedance Frequency Check/limiter output level (Pin 9) (Pin 9) RF/IF section (int LO) NOTE: 1. The generator source impedance is 50Ω, but the SA617 input impedance at Pin 18 is 1500Ω. As a result, IF level refers to the actual signal that enters the SA617 input (Pin 18) which is about 21dB less than the “available power” at the generator. 1997 Nov 07 4 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system The signal from the second limiting amplifier goes to a Gilbert cell quadrature detector. One port of the Gilbert cell is internally driven by the IF. The other output of the IF is AC-coupled to a tuned quadrature network. This signal, which now has a 90° phase relationship to the internal signal, drives the other port of the multiplier cell. CIRCUIT DESCRIPTION The SA617 is an IF signal processing system suitable for second IF systems with input frequency as high as 150MHz. The bandwidth of the IF amplifier and limiter is at least 2MHz with 90dB of gain. The gain/bandwidth distribution is optimized for 455kHz, 1.5kΩ source applications. The overall system is well-suited to battery operation as well as high performance and high quality products of all types. The demodulated output of the quadrature drives an internal op amp. This op amp can be configured as a unity gain buffer, or for simultaneous gain, filtering, and 2nd-order temperature compensation if needed. It can drive an AC load as low as 2kΩ with a rail-to-rail output. The input stage is a Gilbert cell mixer with oscillator. Typical mixer characteristics include a noise figure of 6.2dB, conversion gain of 17dB, and input third-order intercept of –9dBm. The oscillator will operate in excess of 200MHz in L/C tank configurations. Hartley or Colpitts circuits can be used up to 100MHz for xtal configurations. Butler oscillators are recommended for xtal configurations up to 150MHz. A log signal strength completes the circuitry. The output range is greater than 90dB and is temperature compensated. This log signal strength indicator exceeds the criteria for AMPs or TACs cellular telephone. This signal is buffered through an internal unity gain op amp. The frequency check pin provides a buffered limiter output. This is useful for implementing an AFC (Automatic Frequency Check) function. This same output can also be used in conjunction with limiter output (Pin 11) for demodulating FSK (Frequency Shift Keying) data. Both pins are of the same amplitude, but 180° out of phase. The output impedance of the mixer is a 1.5kΩ resistor permitting direct connection to a 455kHz ceramic filter. The input resistance of the limiting IF amplifiers is also 1.5kΩ. With most 455kHz ceramic filters and many crystal filters, no impedance matching network is necessary. The IF amplifier has 43dB of gain and 5.5MHz bandwidth. The IF limiter has 60dB of gain and 4.5MHz bandwidth. To achieve optimum linearity of the log signal strength indicator, there must be a 12dB(v) insertion loss between the first and second IF stages. If the IF filter or interstage network does not cause 12dB(v) insertion loss, a fixed or variable resistor or an L pad for simultaneous loss and impedance matching can be added between the first IF output (Pin 16) and the interstage network. The overall gain will then be 90dB with 2MHz bandwidth. 1997 Nov 07 SA617 NOTE: Limiter output or Frequency Check output has drive capability of a load minimum of 2kΩ or higher to obtain 115mV output level. NOTE: dB(v) = 20log VOUT/VIN 5 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system –25dB, –10dB, 1500/50Ω PAD 50/50Ω PAD –29dB, 929/50Ω PAD 51.5 96.5 50.5 2430 3880 71.5 32.6 C20 C24 SW9 FLT1 SW8 19 C26 96.5 R18 3.3k 32.8 18 SW7 17 FLT2 16 –36dB, 156k/50Ω PAD 51.7 71.5 1.3k C16 C19 C21 C23 20 –10.6dB, 50/50Ω PAD R17 2.4k C22 SA617 15 SW6 C15 SW5 C18 14 C17 13 IF AMP 12 11 LIMITER MIXER RSSI QUAD OSCILLATOR – + – + VREG AUDIO 1 2 3 4 5 6 7 8 9 10 C26 SW1 C1 SW3 R11 R9 SW4 SW10 C12 L1 C2 R4 51.1 R1 C3 R3 R2 SW11 C27 C7 SW2 R10 C9 C8 C5 C10 L2 R17 R12 DEEMPHASIS FILTER IFT1 R19 16k X1 C6 C4 EXT. LOC OSC 44.545 R7 30.5 45MHZ 45.06 MHZ R6 178 ”C” WEIGHTED AUDIO MEASUREMENT CIRCUIT R8 39.2 RSSI OUT MINI–CIRCUIT ZSC2–1B VCC C14 AUDIO OUT Automatic Test Circuit Component List C1 C2 C5 C6 C7 C8 C9 C10 C12 C14 C15 C17 C18 C21 C23 C25 100pF NPO Ceramic 390pF NPO Ceramic 100nF +10% Monolithic Ceramic 22pF NPO Ceramic 1nF Ceramic 10.0pF NPO Ceramic 100nF +10% Monolithic Ceramic 15µF Tantalum (minimum) 2.2µF 100nF +10% Monolithic Ceramic 10pF NPO Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic C26 C27 Flt 1 Flt 2 IFT 1 L1 L2 X1 R9 R10 R11 R12 R14 R17 R18 R19 0.1µF +10% Monolithic Ceramic 2.2µF Ceramic Filter Murata SFG455A3 or equiv Ceramic Filter Murata SFG455A3 or equiv 455kHz (Ce = 180pF) Toko RMC–2A6597H 147–160nH Coilcraft UNI–10/142–04J08S 3.3µH nominal Toko 292CNS–T1046Z 44.545MHz Crystal ICM4712701 2kΩ +1% 1/4W Metal Film 8.2kΩ +1% 10kΩ +1% 2kΩ +1% 10kΩ +1% 2.4kΩ +5% 1/4W Carbon Composition 3.3kΩ +5% 1/4W Carbon Composition 16kΩ +5% 1/4W Carbon Composition Figure 3. SA617 45MHz Test Circuit (Relays as shown) 1997 Nov 07 6 SR00407 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 C26 R18 3.3k R17 2.4k C15 FLT1 20 19 FLT2 C21 C23 18 17 15 16 C18 14 C17 13 IF AMP 12 11 LIMITER MIXER RSSI QUAD OSCILLATOR – + – + VREG AUDIO 1 2 3 5 4 6 7 9 8 10 C1A R11 C9 C1 C8 C2 C12 R10 L1 C7 C27 C10 C5 IFT1 L2 45MHz INPUT R19 11k C19 390pF X1 C6 C14 RSSI OUTPUT VCC AUDIO FREQ CHECK SA617DK Application Component List C1A C1 C2 C5 C6 C7 C8 C9 C10 C12 C14 C15 C17 C18 C19 C21 C23 C26 C27 Flt 1 Flt 2 IFT 1 L1 L2 X1 R5 R10 R11 R17 R18 R19 18pF NPO Ceramic 33pF NPO Ceramic 220pF NPO Ceramic 100nF +10% Monolithic Ceramic 30pF trim cap 1nF Ceramic 10.0pF NPO Ceramic 100nF +10% Monolithic Ceramic 15µF Tantalum (minimum) 2.2µF +10% Tantalum 100nF +10% Monolithic Ceramic 10pF NPO Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 390pF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 100nF +10% Monolithic Ceramic 2.2µF Tantalum Ceramic Filter Murata SFG455A3 or equiv Ceramic Filter Murata SFG455A3 or equiv 330µH TOKO 303LN-1130 .33µH TOKO SCB-1320Z 1.2µH 44.545MHz Crystal ICM4712701 Not Used in Application Board (see Note 8, pg 8) 8.2k +5% 1/4W Carbon Composition 10k +5% 1/4W Carbon Composition 2.4k +5% 1/4W Carbon Composition 3.3k +5% 1/4W Carbon Composition 11k +5% 1/4W Carbon Composition SR00408 Figure 4. SA617 45MHz Application Circuit 1997 Nov 07 7 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system RF GENERATOR 45MHz SA617 NE617 DEMO BOARD RSSI AUDIO VCC (+3) DE-EMPHASIS FILTER DC VOLTMETER C–MESSAGE SCOPE HP339A DISTORTION ANALYZER SR00409 Figure 5. SA617 Application Circuit Test Set Up NOTES: 1. C-message: The C-message and de-emphasis filter combination has a peak gain of 10 for accurate measurements. Without the gain, the measurements may be affected by the noise of the scope and HP339 analyzer. The de-emphasis filter has a fixed -6dB/Octave slope between 300Hz and 3kHz. 2. Ceramic filters: The ceramic filters can be 30kHz SFG455A3s made by Murata which have 30kHz IF bandwidth (they come in blue), or 16kHz CFU455Ds, also made by Murata (they come in black). All of our specifications and testing are done with the more wideband filter. 3. RF generator: Set your RF generator at 45.000MHz, use a 1kHz modulation frequency and a 6kHz deviation if you use 16kHz filters, or 8kHz if you use 30kHz filters. 4. Sensitivity: The measured typical sensitivity for 12dB SINAD should be 0.35µV or –116dBm at the RF input. 5. Layout: The layout is very critical in the performance of the receiver. We highly recommend our demo board layout. 6. RSSI: The smallest RSSI voltage (i.e., when no RF input is present and the input is terminated) is a measure of the quality of the layout and design. If the lowest RSSI voltage is 500mV or higher, it means the receiver is in regenerative mode. In that case, the receiver sensitivity will be worse than expected. 7. Supply bypass and shielding: All of the inductors, the quad tank, and their shield must be grounded. A 10-15µF or higher value tantalum capacitor on the supply line is essential. A low frequency ESR screening test on this capacitor will ensure consistent good sensitivity in production. A 0.1µF bypass capacitor on the supply pin, and grounded near the 44.545MHz oscillator improves sensitivity by 2-3dB. 8. R5 can be used to bias the oscillator transistor at a higher current for operation above 45MHz. Recommended value is 22kΩ, but should not be below 10kΩ. 1997 Nov 07 8 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 mA 6 VCC = 7V 5 VCC = 5V ICC (mA) 4 VCC = 3V 3 VCC = 2.7V °C 2 –55 –35 –15 5 25 45 65 85 105 TEMPERATURE (°C) 125 SR00410 Figure 6. ICC vs Temperature –8.0 –8.5 50 Ω INPUT INTERCEPT POINT (dBm) –9.0 2.7V 3V –9.5 –10.0 7V –10.5 –11.0 –11.5 –12.0 –12.5 –13.0 –13.5 –14.0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 Temperature (°C) Figure 7. Third Order Intercept Point vs Supply Voltage 1997 Nov 07 9 80 SR00411 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 18.00 17.75 2.7V CONVERSION GAIN (dB) 17.50 3V 17.25 7.0V 17.00 16.75 16.50 16.25 16.00 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) SR00413 Figure 8. Mixer Noise Figure vs Supply Voltage 18.00 17.75 2.7V CONVERSION GAIN (dB) 17.50 3V 17.25 7.0V 17.00 16.75 16.50 16.25 16.00 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) SR00414 Figure 9. Conversion Gain vs Supply Voltage 1997 Nov 07 10 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 20 10 0 RF = 45MHz IF = 455kHz IF OUTPUT POWER (–dBm) –10 –20 –30 –40 3rd ORDER PRODUCT FUND PRODUCT –50 –60 –70 *50Ω INPUT –80 –66 –56 –46 –36 –26 –16 –6 4 14 24 34 RF* INPUT LEVEL (dBm) SR00415 Figure 10. Mixer Third Order Intercept and Compression 1997 Nov 07 11 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 5 AUDIO 0 –5 DECIBELS (dB) –10 –15 VCC = 3V RF = 45MHz –20 DEVIATION = ±8kHz AUDIO LEVEL = 104.9mVRMS –25 –30 AM REJECTION –35 –40 THD + NOISE –45 –50 –55 –60 NOISE –65 –125 –115 –105 –95 –85 –75 –65 –55 –45 –35 –25 RF LEVEL (dBm) SR00416 Figure 11. Sensitivity vs RF Level (–40°C) 5 AUDIO 0 –5 –10 DECIBELS (dB) VCC = 3V RF = 45MHz –20 DEVIATION = ±8kHz –25 AUDIO LEVEL = 117.6mVRMS –30 AM REJECTION –35 –40 –45 –50 THD + NOISE –55 –60 –65 –125 NOISE –115 –105 –95 –85 –75 –65 –55 –45 –35 –25 RF LEVEL (dBm) SR00417 Figure 12. Sensitivity vs RF Level (+25°C) 1997 Nov 07 12 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 5 AUDIO 0 –5 DECIBELS (dB) –10 –15 VCC = 3V RF = 45MHz –20 DEVIATION = ±8kHz AUDIO LEVEL = 127mVRMS –25 –30 AM REJECTION –35 –40 –45 THD + NOISE –50 –55 –60 –65 –125 NOISE –115 –105 –95 –85 –75 –65 –55 –45 –35 –25 RF LEVEL (dBm) SR00418 Figure 13. Sensitivity vs RF Level (Temperature 85°C) 5 AUDIO 0 –5 –10 VCC = 3V RF = 45MHz RF LEVEL = –45dBm –15 DECIBELS (dB) –20 DEVIATION = ±8kHz AUDIO LEVEL = +117.6mVRMS –25 –30 –35 –40 DISTORTION –45 –50 AM REJECTION –55 –60 NOISE –65 –55 –35 –15 5 25 45 TEMPERATURE (°C) 65 85 105 Figure 14. Relative Audio Level, Distortion, AM Rejection and Noise vs Temperature 1997 Nov 07 13 125 SR00419 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 2.400 2.000 +85°C VOLTAGE (V) 1.600 ROOM 1.200 –40°C 0.800 0.400 0.000 –95 –85 –75 –65 –55 –45 –35 –25 –15 –5 5 IF LEVEL (dBm) SR00420 Figure 15. RSSI (455kHz IF @ 3V) 2.1 2.0 1.9 1.8 1.7 1.6 VOLTAGE (V) 1.5 1.4 +85°C 1.3 +27°C 1.2 –40°C 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 –125 –115 –105 –95 –85 –75 –65 –55 –45 –35 –25 RF LEVEL (dBm) SR00421 Figure 16. RSSI vs RF Level and Temperature - VCC = 3V 1997 Nov 07 14 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 V 300 VCC = 7V 250 mV RMS 200 VCC = 5V 150 VCC = 3V 100 VCC = 2.7V 50 °C 0 –55 –35 –15 5 25 45 65 85 105 125 SR00422 Figure 17. Audio Output vs Temperature 1997 Nov 07 15 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SSOP20: plastic shrink small outline package; 20 leads; body width 4.4 mm 1997 Nov 07 16 SA617 SOT266-1 Philips Semiconductors Product specification Low-voltage high performance mixer FM IF system SA617 DEFINITIONS Data Sheet Identification Product Status Definition Objective Specification Formative or in Design This data sheet contains the design target or goal specifications for product development. Specifications may change in any manner without notice. Preliminary Specification Preproduction Product This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. Product Specification Full Production This data sheet contains Final Specifications. Philips Semiconductors reserves the right to make changes at any time without notice, in order to improve design and supply the best possible product. Philips Semiconductors and Philips Electronics North America Corporation reserve the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. LIFE SUPPORT APPLICATIONS Philips Semiconductors and Philips Electronics North America Corporation Products are not designed for use in life support appliances, devices, or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected to result in a personal injury. Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale. Copyright Philips Electronics North America Corporation 1997 All rights reserved. Printed in U.S.A. Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088–3409 Telephone 800-234-7381 1997 Nov 07 17