RF COMMUNICATIONS PRODUCTS SA625 High performance low power mixer FM IF system with high-speed RSSI Product specification Replaces data of November 3, 1992 IC17 Data Handbook Philips Semiconductors 1997 Nov 07 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI DESCRIPTION SA625 PIN CONFIGURATION The SA625 is pin-to-pin compatible with the SA605, but has faster RSSI rise and fall times. The SA625 is a high performance monolithic low-power FM IF system incorporating a mixer/oscillator, two limiting intermediate frequency amplifiers, quadrature detector, muting, logarithmic received signal strength indicator (RSSI) with fast rise and fall time, and voltage regulator. The SA625 combines the functions of Signetics’ SA602A and SA624. The SA625 is available in 20-lead SSOP (shrink small outline package). DK Package RFIN 1 RF BYPASS 2 XTAL OSC For additional technical information please refer to application notes AN1994, 1995 and 1996, which include example application diagrams, a complete overview of the product and artwork for reference. FEATURES • Fast RSSI rise and fall times • Low power consumption: 5.8mA typical at 6V • Mixer input to >500MHz • Mixer conversion power gain of 13dB at 45MHz • Mixer noise figure of 4.6dB at 45MHz • XTAL oscillator effective to 150MHz (L.C. oscillator to 1GHz local 20 MIXER OUT 19 IF AMP DECOUPLING 3 18 IF AMP IN XTAL OSC 4 17 MUTEIN 5 16 IF AMP OUT VCC 6 15 GND RSSIOUT 7 14 LIMITER IN IF AMP DECOUPLING MUTED AUDIO OUT 8 13 LIMITER DECOUPLING UNMUTED AUDIO OUT 9 12 LIMITER DECOUPLING QUADRATURE IN 10 11 LIMITER OUT SR00456 • ESD hardened Figure 1. Pin Configuration APPLICATIONS • Digital cellular base stations • High performance communications receivers • Single conversion VHF/UHF receivers • SCA receivers • RF level meter • Spectrum analyzer • Instrumentation • FSK and ASK data receivers • Log amps • Wideband low current amplification • Digital cordless telephones oscillator can be injected) • 102dB of IF Amp/Limiter gain • 25MHz limiter small signal bandwidth • Temperature compensated logarithmic Received Signal Strength Indicator (RSSI) with a dynamic range in excess of 90dB • Two audio outputs - muted and unmuted • Low external component count; suitable for crystal/ceramic/LC filters • Excellent sensitivity: 0.22µV into 50Ω matching network for 12dB SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF at 45MHz and IF at 455kHz • SA625 meets cellular radio specifications ORDERING INFORMATION DESCRIPTION TEMPERATURE RANGE 20-Pin Plastic Shrink Small Outline Package (SSOP) (Surface-mount) 1997 Nov 07 -40 to +85°C 2 ORDER CODE DWG # SA625DK SOT266-1 853-1648 18664 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 BLOCK DIAGRAM 20 19 18 17 16 15 14 13 IF AMP 12 11 LIMITER RSSI OSCILLATOR 1 2 E B 3 4 5 6 7 8 9 10 SR00457 Figure 2. Block Diagram ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER VCC Single supply voltage TSTG RATING UNITS 9 V Storage temperature range -65 to +150 °C TA Operating ambient temperature range SA625 -40 to +85 °C θJA Thermal impedance 117 °C/W DK package DC ELECTRICAL CHARACTERISTICS VCC = +6V, TA = 25°C; unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS SA625 MIN VCC Power supply voltage range 4.5 ICC DC current drain 4.55 Mute switch input threshold (ON) 1.7 (OFF) 1997 Nov 07 UNITS TYP MAX 8.0 V 5.8 6.75 mA V 1.0 3 V Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 AC ELECTRICAL CHARACTERISTICS TA = 25°C; VCC = +6V, unless otherwise stated. RF frequency = 45MHz + 14.5dBV RF input step-up; IF frequency = 455kHz; R17 = 5.1k; RF level = -45dBm; FM modulation = 1kHz with ±8kHz peak deviation. Audio output with C-message weighted filter and de-emphasis capacitor. Test circuit Figure 3. 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 SA625 TEST CONDITIONS MIN TYP UNITS MAX Mixer/Osc section (ext LO = 300mV) fIN fOSC Input signal frequency 500 MHz Crystal oscillator frequency 150 MHz Noise figure at 45MHz 5.0 dB -10 dBm Third-order input intercept point f1 = 45.0; f2 = 45.06MHz Conversion power gain Matched 14.5dBV step-up 10 50Ω source RF input resistance Single-ended input 3.0 Mixer output resistance (Pin 20) 1.25 IF amp gain Limiter gain RF input capacitance 13 15 dB -1.7 dB 4.7 kΩ 3.5 4.0 pF 1.5 kΩ 50Ω source 39.7 dB 50Ω source 62.5 dB Input limiting -3dB, R17 = 5.1k Test at Pin 18 -113 dBm AM rejection 80% AM 1kHz 29 34 43 dB Audio level, R10 = 100k 15nF de-emphasis 80 150 260 mVRMS Unmuted audio level, R11 = 100k 150pF de-emphasis 480 mV SINAD sensitivity RF level -118dB 16 dB -42 dB IF section THD Total harmonic distortion -34 S/N Signal-to-noise ratio No modulation for noise IF RSSI output, R9 = 100kΩ1 IF level = -118dBm 0 160 650 mV IF level = -68dBm 1.9 2.5 3.1 V IF level = -18dBm 4.0 4.8 5.6 V 73 dB IF frequency = 455kHz RF level = -56dBm 1.2 µs IF RSSI output rise time RF level = -28dBm 1.2 µs (10kHz pulse, no 455kHz filter) IF frequency = 10.7MHz (no RSSI bypass capacitor) RF level = -56dBm 1.2 µs RF level = -28dBm 1.1 µs IF frequency = 455kHz 1997 Nov 07 RF level = -56dBm 2.1 µs IF RSSI output fall time RF level = -28dBm 7.6 µs (10kHz pulse, no 455kHz filter) IF frequency = 10.7MHz (no RSSI bypass capacitor) RF level = -56dBm 2.0 µs RF level = -28dBm 7.3 µs RSSI range R9 = 100kΩ Pin 16 90 dB RSSI accuracy R9 = 100kΩ Pin 16 +1.5 dB IF input impedance 1.40 1.6 kΩ IF output impedance 0.85 1.0 kΩ Limiter intput impedance 1.40 1.6 kΩ Limiter output impedance 300 Ω Limiter output level with no load 280 mVRMS 4 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 AC ELECTRICAL CHARACTERISTICS(Continued) LIMITS SYMBOL PARAMETER TEST CONDITIONS SA625 MIN TYP UNITS MAX IF section (continued) Unmuted audio output resistance 58 kΩ Muted audio output resistance 58 kΩ RF/IF section (int LO) Unmuted audio level 4.5V = VCC, RF level = -27dBm 450 mVRMS System RSSI output 4.5V = VCC, RF level = -27dBm 4.3 V NOTE: 1. The generator source impedance is 50Ω, but the SA625 input impedance at Pin 18 is 1500Ω. As a result, IF level refers to the actual signal that enters the SA625 input (Pin 8) which is about 21dB less than the ”available power” at the generator. network does not cause 12dB(v) insertion loss, a fixed or variable resistor can be added between the first IF output (Pin 16) and the interstage network. CIRCUIT DESCRIPTION The SA625 is an IF signal processing system suitable for second IF or single conversion systems with input frequency as high as 1GHz. The bandwidth of the IF amplifier is about 40MHz, with 39.7dB(v) of gain from a 50Ω source. The bandwidth of the limiter is about 28MHz with about 62.5dB(v) of gain from a 50Ω source. However, 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 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. Overall, the IF section has a gain of 90dB. For operation at intermediate frequencies greater than 455kHz, special care must be given to layout, termination, and interstage loss to avoid instability. The input stage is a Gilbert cell mixer with oscillator. Typical mixer characteristics include a noise figure of 5dB, conversion gain of 13dB, and input third-order intercept of -10dBm. The oscillator will operate in excess of 1GHz 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. The demodulated output of the quadrature detector is available at two pins, one continuous and one with a mute switch. Signal attenuation with the mute activated is greater than 60dB. The mute input is very high impedance and is compatible with CMOS or TTL levels. The output of the mixer is internally loaded with 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. 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 1997 Nov 07 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. NOTE: dB(v) = 20log VOUT/VIN 5 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI -25dB, -10dB, 1500/50Ω PAD 50/50Ω PAD -29dB, 929/50Ω PAD 2430 3880 SW8 19 18 SW7 16 C16 SW6 FLT2 17 1.3k C19 C21 C23 20 71.5 R17 5.1k C22 FLT1 51.7 32.8 C20 C24 -36dB, 156k/50Ω PAD 96.5 71.5 32.6 SW9 -10.6dB, 50/50Ω PAD 51.5 96.5 50.5 SA625 15 C15 SW5 C18 14 C17 13 12 11 IF AMP 700 LIMITER MIXER QUAD DETECTOR OSCILLATOR RSSI EMITTER 1 2 BASE 3 SW1 C1 MUTE SWITCH 4 SW3 5 SW4 6 7 C9 R9 C10 C11 8 R10 9 10 R11 C8 L1 C2 C7 R4 51.1 SW2 R1 C3 R3 R2 C13 IFT1 L2 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 MUTE MINI–CIRCUIT ZSC2–1B C1 C2 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C17 C18 C12 C5 VCC RSSI AUDIO UNMUTED AUDIO OUTPUT Automatic Test Circuit Component List 100pF NPO Ceramic C21 100nF ±10% Monolithic Ceramic 390pF NPO Ceramic C23 100nF ±10% Monolithic Ceramic C25 100nF ±10% Monolithic Ceramic 100nF ±10% Monolithic Ceramic Flt 1 Ceramic Filter Murata SFG455A3 or equiv 22pF NPO Ceramic Flt 2 Ceramic Filter Murata SFG455A3 or equiv 1nF Ceramic IFT 1 455kHz (Ce = 180pF) Toko RMC–2A6597H 10.0pF NPO Ceramic L1 147–160nH Coilcraft UNI–10/142–04J08S 100nF ±10% Monolithic Ceramic L2 0.8µH nominal 6.8µF Tantalum (minimum) * Toko 292CNS–T1038Z 100nF ±10% Monolithic Ceramic X1 44.545MHz Crystal ICM4712701 15nF ±10% Ceramic R9 100k ±1% 1/4W Metal Film 150pF ±2% N1500 Ceramic R17 5.1k ±5% 1/4W Carbon Composition 100nF ±10% Monolithic Ceramic R10 100k ±1% 1/4W Metal Film (optional) 10pF NPO Ceramic R11 100k ±1% 1/4W Metal Film (optional) 100nF ±10% Monolithic Ceramic 100nF ±10% Monolithic Ceramic *NOTE: This value can be reduced when a battery is the power source. SR00458 Figure 3. SA625 45MHz Test Circuit (Relays as shown) 1997 Nov 07 C14 6 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 R17 5.1k C15 FLT1 20 19 FLT2 C21 C23 18 17 16 15 C18 14 C17 13 12 11 IF AMP 700 LIMITER MIXER QUAD DETECTOR OSCILLATOR RSSI 1 2 3 4 5 6 C1 MUTE SWITCH 7 C9 R9 C10 C11 8 R10 9 10 R11 C8 C2 L1 R5 C7 C12 C13 C5 IFT1 L2 45MHz INPUT X1 C6 C25 C14 MUTE VCC RSSI AUDIO UNMUTED AUDIO OUTPUT Application Component List C1 C2 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C17 C18 C21 C23 C25 Flt 1 Flt 2 IFT 1 L1 L2 100pF NPO Ceramic 390pF NPO Ceramic 100nF ±10% Monolithic Ceramic 22pF NPO Ceramic 1nF Ceramic 10.0pF NPO Ceramic 100nF ±10% Monolithic Ceramic 6.8µF Tantalum (minimum) * 100nF ±10% Monolithic Ceramic 15nF ±10% Ceramic 150pF ±2% N1500 Ceramic 100nF ±10% Monolithic Ceramic 10pF NPO Ceramic 100nF ±10% Monolithic Ceramic 100nF ±10% Monolithic Ceramic X1 R9 R17 R5 R10 R11 100nF ±10% Monolithic Ceramic 100nF ±10% Monolithic Ceramic 100nF ±10% Monolithic Ceramic 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 0.8µH nominal Toko 292CNS–T1038Z 44.545MHz Crystal ICM4712701 100k ±1% 1/4W Metal Film 5.1k ±5% 1/4W Carbon Composition Not Used in Application Board (see Note 8) 100k ±1% 1/4W Metal Film (optional) 100k ±1% 1/4W Metal Film (optional) *NOTE: This value can be reduced when a battery is the power source. SR00459 Figure 4. SA625 45MHz Application Circuit 1997 Nov 07 7 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI RF GENERATOR 45MHz SA625 NE625 DEMO BOARD VCC (+6) RSSI AUDIO DATA C–MESSAGE DC VOLTMETER SCOPE HP339A DISTORTION ANALYZER SR00460 Figure 5. SA625 Application Circuit Test Set Up NOTES: 1. C-message: The C-message filter has a peak gain of 100 for accurate measurements. Without the gain, the measurements may be affected by the noise of the scope and HP339 analyzer. 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 0.22µV or -120dBm 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 250mV 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 High performance low power mixer FM IF system with high-speed RSSI SA625 20 RF = 45MHz IF = 455kHz VCC = 6V RELATIVE TO AUDIO OUTPUT (dB) AUDIO REF = 174mVRMS 0 5 –20 4 + THD NOISE 3 –40 AM (80%) 2 –60 –80 –100 –130 1 NOISE RSSI (Volts) 0 –110 –90 –70 –50 –30 RF INPUT LEVEL (dBm) Figure 6. SA625 Application Board at 25°C 1997 Nov 07 RSSI (Volts) 9 –10 10 SR00461 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI TOP VIEW 1.6 in. TOP SILK SCREEN SA625 1.7 in. BOTTOM VIEW Figure 7. SA625 SSOP Demo-board Layout (Not Actual Size) 1997 Nov 07 10 SR00465 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 1.70 1.65 RSSI RISE TIME ( µ s) 1.60 1.55 RFINP–38dBm 1.50 RFINP–28dBm 1.45 RFINP–56dBm 1.40 1.35 1.30 1.25 1.20 1.15 1.10 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (°C) SR00466 Figure 8. SA625 Rise Time 455kHz IF Frequency 8.0 7.5 7.0 RSSI FALL TIME ( µ s) 6.5 6.0 5.5 5.0 4.5 RFINP–28dBm 4.0 RFINP–38dBm RFINP–56dBm 3.5 3.0 2.5 2.0 1.5 1.0 –40 –30 –20 –10 0 10 20 30 40 50 TEMPERATURE (°C) Figure 9. SA625 Fall Time 455kHz IF Frequency 1997 Nov 07 11 60 70 80 90 SR00467 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 1.65 RFINP–56dBm RFINP–28dBm RFINP–38dBm 1.60 RSSI RISE TIME ( µ s) 1.55 1.50 1.45 1.40 1.35 1.30 1.25 1.20 1.15 1.10 1.00 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (°C) SR00468 Figure 10. SA625 Rise Time 10.7MHz IF Frequency 8.0 7.5 7.0 6.0 RFINP–28dBm RFINP–38dBm 5.5 RFINP–56dBm RSSI FALL TIME ( µ s) 6.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 –40 –30 –20 –10 0 10 20 30 40 50 TEMPERATURE (°C) Figure 11. SA625 Fall Time 10.7MHz IF Frequency 1997 Nov 07 12 60 70 80 90 SR00469 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SSOP20: plastic shrink small outline package; 20 leads; body width 4.4 mm 1997 Nov 07 13 SA625 SOT266-1 Philips Semiconductors Product specification High performance low power mixer FM IF system with high-speed RSSI SA625 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 14