SA636 Low voltage high performance mixer FM IF system with high-speed RSSI

Transcription

1 RF COMMUNICATIONS PRODUCTS Low voltage high performance mixer FM IF system Replaces data of 1994 Jun Nov 7 IC17 Data Handbook Philips Semiconductors

2 Low voltage high performance mixer FM IF system DESCRIPTION The 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 (), voltage regulator, wideband data output and fast op amps. The is available in -lead SSOP (shrink small outline package). PIN CONFIGURATION DK Package RF IN 1 RF BYPASS 19 MIXER OUT IF AMP DECOUPLING The was designed for high bandwidth portable communication applications and will function down to. The RF section is similar to the famous SA65. The data output has a minimum bandwidth of 6kHz. This is designed to demodulate wideband data. The output is amplified. The output has access to the feedback pin. This enables the designer to adjust the level of the outputs or add filtering. incorporates a power down mode which powers down the device when Pin 8 is low. Power down logic levels are CMOS and TTL compatible with high input impedance. XTAL OSC (EMITTER) XTAL OSC (BASE) FEEDBACK OUT POWER DOWN CONTROL DATA OUT QUADRATURE IN IF AMP IN IF AMP DECOUPLING IF AMP OUT GND LIMITER IN LIMITER DECOUPLING LIMITER DECOUPLING LIMITER OUT APPLICATIONS DECT (Digital European Cordless Telephone) Digital cordless telephones Digital cellular telephones Portable high performance communications receivers Single conversion VHF/UHF receivers FSK and ASK data receivers Wireless LANs FEATURES Wideband data output (6kHz min.) Fast rise and fall times Low power consumption: 6.5mA typ at 3V Mixer input to >5MHz Mixer conversion power gain of 11dB at 4MHz Mixer noise figure of 1dB at 4MHz Figure 1. Pin Configuration SR491 XTAL oscillator effective to 15MHz (L.C. oscillator to 1GHz local oscillator can be injected) 9dB of IF Amp/Limiter gain 5MHz limiter small signal bandwidth Temperature compensated logarithmic Received Signal Strength Indicator () with a dynamic range in excess of 9dB output internal op amp Internal op amps with rail-to-rail outputs Low external component count; suitable for crystal/ceramic/lc filters Excellent sensitivity:.54µv into 5Ω matching network for 1dB SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF at 4MHz and IF at 1.7MHz ESD hardened 1.7MHz filter matching (33Ω) Power down mode (I CC = µa) ORDERING INFORMATION DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG # -Pin Plastic Shrink Small Outline Package (Surface-mount) -4 to +85 C DK SOT Nov

3 BLOCK DIAGRAM IF AMP GND LIMITER MIXER OSCILLATOR FAST QUAD + PWR + DWN E B AUDIO SR49 Figure. Block Diagram ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER RATING UNITS Single supply voltage.3 to 7 V V IN Voltage applied to any other pin.3 to ( +.3) V T STG Storage temperature range -65 to +15 C T A Operating ambient temperature range 4 to +85 C NOTE: θ JA, Thermal impedance DK package 117 C/W DC ELECTRICAL CHARACTERISTICS = +3V, T A = 5 C; unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS UNITS MIN TYP MAX Power supply voltage range V I CC DC current drain Pin 8 = HIGH ma Input current Pin 8 LOW 1 1 Pin 8 HIGH 1 1 µa Pin 8 LOW.3 Input level Pin 8 HIGH.7 V I CC Standby Pin 8 = LOW..5 ma t ON Power up time valid (1% to 9%) 1 µs t OFF Power down time invalid (9% to 1%) 5 µs 1997 Nov 7 3

4 AC ELECTRICAL CHARACTERISTICS T A = 5 C; = +3V, unless otherwise stated. RF frequency = 4.5MHz dBV RF input step-up; IF frequency = 1.7MHz; RF level = -45dBm; FM modulation = 1kHz with ±15kHz peak deviation. Audio output with C-message weighted filter and de-emphasis capacitor. Test circuit Figure 1. The parameters listed below are tested using automatic test equipment to assure consistent electrical characteristics. 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 UNITS Mixer/Osc section (ext LO = 16mV RMS ) MIN TYP MAX f IN Input signal frequency 5 MHz f OSC External oscillator (buffer) 5 MHz IF section Noise figure at 4MHz 1 db Third-order input intercept point Matched f1=4.5; f=4.35mhz -16 dbm Conversion power gain Matched 14.5dBV step-up db RF input resistance Single-ended input 7 Ω RF input capacitance 3.5 pf Mixer output resistance (Pin ) 33 Ω IF amp gain 33Ω load 38 db Limiter gain 33Ω load 54 db Input limiting -3dB Test at Pin dbm AM rejection 8% AM 1kHz 5 db Data level R LOAD = 1kΩ 1 13 mv RMS 3dB data bandwidth 6 7 khz SINAD sensitivity RF level = -111dBm 16 db THD Total harmonic distortion db S/N Signal-to-noise ratio No modulation for noise 6 db RF/IF section (int LO) IF level = -118dBm..5 V IF output with buffer IF level = -68dBm V IF output rise time IF level = -1dBm V IF frequency = 1.7MHz (1kHz pulse, no 1.7MHz filter) RF level = -56dBm 1. µs (no bypass capacitor) RF level = -8dBm 1.1 µs IF output fall time IF frequency = 1.7MHz (1kHz pulse, no 1.7MHz filter) RF level = -56dBm. µs (no bypass capacitor) RF level = -8dBm 7.3 µs range 9 db accuracy +1.5 db IF input impedance 33 Ω IF output impedance 33 Ω Limiter input impedance 33 Ω Limiter output impedance 3 Ω Limiter output level with no load 13 mv RMS System output RF level = -1dBm 1.4 V System SINAD RF level = -16dBm 1 db 1997 Nov 7 4

5 PERFORMANCE CHARACTERISTICS 9..5 SUPPLY CURRENT (ma) = 5V = 3V = POWER DOWN SUPPLY CURRENT (ma) = 5V = 3V = MIXER GAIN (db) TEMPERATURE ( C) Supply Current vs Temperature and Supply Voltage Mixer Power Gain vs Temperature and Supply Voltage V RF level = -45 dbm TEMPERATURE ( C) Power Down Supply Current vs Temperature and Supply Voltage MIXER IIP3 (deb) Mixer IIP3 at 4MHz vs Temperature and Supply Voltage AUDIO RF level = -45 dbm 3.V AUDIO REFERENCE (mvrms) V AUDIO (db) AM REJECTION DISTORTION NOISE 5 1 1dB SINAD Audio Reference Level vs Temperature and Supply Voltage 1 Figure 3. Performance Characteristics TEMPERATURE ( C) 1dB SINAD and Relative Audio, THD, Noise and AM Rejection for VCC = 3V vs Temperature RF = 4MHz, Level = 68dBm, Deviation = 15kHz SR Nov 7 5

6 PERFORMANCE CHARACTERISTICS (continued) RELATIVE TO AUDIO OUTPUT (db) AUDIO AM REJECTION THD+N NOISE (V) RELATIVE TO AUDIO OUTPUT (db) AUDIO AM REJECTION THD+N NOISE (V) RELATIVE TO AUDIO OUTPUT (db) RF INPUT LEVEL (dbm) Receiver RF Performance T = 5 C, Audio Level = 19mV RMS 9 8 AUDIO THD+N NOISE AM REJECTION 6 Receiver RF Performance T = 85 C, Audio Level = 131mV RMS (V) IF OUTPUT POWER (dbm) RF INPUT LEVEL (dbm) Receiver RF Performance T = 4 C, Audio Level = 118mV RMS RF INPUT POWER (dbm) Mixer Third Order Intercept and Compression MIXER IIP3 (db) RF level = -45 dbm 3.V RF INPUT LEVEL (dbm) Mixer IIP3 at 4MHz vs Temperature and Supply Voltage vs RF Input Level and Temperature SR494 Figure 4. Performance Characteristics (V) C 4 C 85 C Nov 7 6

7 PERFORMANCE CHARACTERISTICS (continued) POWER GAIN (db) = 5V = 3V = POWER GAIN (db) = 5V VCC = 3V = TEMPERATURE ( C) SA66 IF Amplifier Gain vs Temperature vs Supply Voltage TEMPERATURE ( C) SA66 Limiting Amplifier Gain vs Temperature vs Supply Voltage kHz Data Rate, IF = 9.85MHz, Dev = 88kHz, RF = -4dBm.7.6 DATA LEVEL (Vp-p) V DATA LEVEL (Vp-p) V 1kHz Data Rate, IF = 9.85MHz, Dev = 88kHz, RF = -4dBm Data Level vs Temperature and Supply Voltage Data Level vs Temperature and Supply Voltage Figure 5. Performance Characteristics SR Nov 7 7

8 PERFORMANCE CHARACTERISTICS (continued) AUDIO REFERENCE (mvrms) V Audio Reference Level vs Temperature and Supply Voltage DATA LEVEL (Vp-p) kHz Data Rate, IF = 9.85MHz, Dev = 88kHz, RF = -4dBm 3.V Data Level vs Temperature and Supply Voltage kHz Data Rate, IF = 9.85MHz, Dev = 88kHz, RF = -4dBm DATA LEVEL (Vp-p) V Data Level vs Temperature and Supply Voltage Figure 6. Performance Characteristics SR Nov 7 8

9 PIN FUNCTIONS PIN No. PIN MNEMONIC DC V EQUIVALENT CIRCUIT PIN No. PIN MNEMONIC DC V EQUIVALENT CIRCUIT 1 RF IN FEEDBACK k.8k 1 RF BYPASS OUT R 3 XTAL OSC 18k POWER DOWN R MIX 3 4 XTAL OSC 15µA DATA OUT V REF BANDGAP QUAD. IN k µa Figure 7. Pin Functions SR Nov 7 9

10 PIN FUNCTIONS (continued) PIN No. PIN MNEMONIC DC V EQUIVALENT CIRCUIT PIN No. PIN MNEMONIC DC V EQUIVALENT CIRCUIT 11 LIMITER OUT IF AMP OUT Ω k 8.8k 1 LIMITER DECOUP IF AMP DECOUP LIMITER 33Ω IF COUPLING AMP IN Ω 5µA 5µA LIMITER IF AMP IN DECOUP GND MIXER OUT Ω 4µA Figure 8. Pin Functions (cont.) SR Nov 7 1

11 MIXER IF/LIM OUT IF/LIM IN R9 L5 C1 C11 FLT1 1 1 R4 R R3 C14 C16 R5 R6 FLT 1 1 R7 C17 R8 C R1 R11 C13 C15 C18 SW5 C IF AMP LIMITER MIXER OSCILLATOR QUAD C1 + PWR DWN + DATA C1 C3 C4 *L1 C L3 C5 C6 FLT 3 C8 C9 R1 L4 RF IN *L LO IN C7 OUT PWR DWN CTRL FLT 4 DATA OUT C1 Automatic Test Circuit Component List R1 R R3 R4 R5 R6 R7 R8 R9 R1 R11 8.kΩ select 6.4kΩ 347.8Ω 49.9Ω 1kΩ 49.9Ω 6.4kΩ 347.8Ω 49.9Ω 1kΩ 49.9Ω C1 C C3 C4 C5 C6 *C7 C8 C9 C1 C11.1µF 1 5pF select for input match.1µf.1µf 1 5pF select for input match 1pF 6.8µF 1V 1µF 39pF select.1µf.1µf C1 C13 C14 C15 C16 C17 C18 C19 C C1 16pF select 1pF.1µF 1pF.1µF.1µF 1pF 1pF.1µF 1pF L1 L L3 L4 L5 FLT1 FLT FLT3 FLT4 15nH select for input match nh select for input match 47nH select for input match 5.6µH select for input match 1.7.5µH select for mixer output match 1.7MHz (Murata SFE1.7MA5-A) 1.7MHz (Murata SFE1.7MA5-A) C message weighted Active de-emphasis *NOTE: This value can be reduced when a battery is the power source. Figure MHz (RF) / 1.7MHz (IF) Test Circuit SR Nov 7 11

12 SMA RF IN C1 5 3pF L4 68nH J MHz +/ 88kHz L1 18nH U1 C 68pF C1 33pF 1 RF IN MIXER OUT C19 1nF C18 68pF C 1nF RF BYPASS IF AMP DECOUPLING 1 19 J SMA LO IN 1dBm C4 1nF C3 1nF 3 4 XTAL OSC (EMITTER) XTAL OSC (BASE) IF IN IF AMP DECOUPLING C17 1nF R IF OUT 16 C16 1pF 6 FEEDBACK GROUND 15 R3 k R4 33k 7 8 OUT PD CTRL LIMITER IN LIMITER DEC C13 1pF +3V R 1 9 DATA OUT LIMITER DEC 1 GND C5 15µF + C6 1nF 1 QUAD IN LIMITER OUT 11 C11 1nF C1 1nF J3 C7 47pF C1 15pF C14 47pF PWR DWN DATA OUT R5 1.k C8 5-3pF + C9 8pF L.µH C15 33pF L3 68nH R6 56 Figure MHz (RF) / 9.8MHz (IF) DECT Application Circuit SR Nov 7 1

13 Table 1. DECT Application Circuit Electrical Characteristics RF frequency = 11.59MHz; IF frequency = 9.8MHz; RF level = -45dBm; FM modulation = 1kHz with ±88kHz peak deviation. SYMBOL PARAMETER TEST CONDITIONS TYPICAL UNITS Mixer/Osc section (ext LO = 16mV RMS ) PG Conversion power gain 13 db NF Noise Figure at 11MHz 1 db IIP3 Third order input intercept Matched f1 = 11.59; f = 11.89MHz -15 dbm R IN RF input resistance 69 Ω C IN RF input capacitance 3.6 pf IF section IF amp gain 33Ω load 38 db Limiter amp gain 33Ω load 54 db Data level R LOAD = 3kΩ 13 mv RMS 3dB data bandwidth 7 khz RF/IF section (internal LO) System output RF level = -1dBm 1.4 V System S/N 1 RF level = -83dBm 1 db NOTE: 1. 1dB S/N corresponds to BER = 1-3. RF GENERATOR 11.59MHz DEMO BOARD DATA = 3V LO / GENERATOR 1.39MHz DC VOLTMETER SCOPE SPECTRUM ANALYZER SR5 Figure 11. Application Circuit Test Set Up NOTES: 1. RF generator: Set your RF generator at 11.59MHz, use a 1kHz modulation frequency and a ±88kHz deviation.. Layout: The layout is very critical in the performance of the receiver. We highly recommend our demo board layout. 3. : The smallest 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 voltage is 5mV or higher, it means the receiver is in regenerative mode. In that case, the receiver sensitivity will be worse than expected. 4. Supply bypass and shielding: All of the inductors, the quad tank, and their shield must be grounded. A.1µF bypass capacitor on the supply pin improves sensitivity Nov 7 13

14 TOP SILK SCREEN (SSOP) Figure 1. Demoboard Layout (Not Actual Size) SR Nov 7 14

15 CIRCUIT DESCRIPTION The 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 4MHz, with 38dB of gain from a 5Ω source. The bandwidth of the limiter is about 8MHz with about 54dB of gain from a 5Ω source. However, the gain/bandwidth distribution is optimized for 1.7MHz, 33Ω source applications. The overall system is well-suited to battery operation as well as high performance and high quality products of all types, such as cordless and cellular hand-held phones. The input stage is a Gilbert cell mixer with oscillator. Typical mixer characteristics include a noise figure of 14dB, conversion gain of 11dB, and input third-order intercept of -16dBm. The oscillator will operate in excess of 1GHz in L/C tank configurations. Hartley or Colpitts circuits can be used up to 1MHz for xtal configurations. Butler oscillators are recommended for xtal configurations up to 15MHz. The output of the mixer is internally loaded with a 33Ω resistor permitting direct connection to a 1.7MHz ceramic filter for narrowband applications. The input resistance of the limiting IF amplifiers is also 33Ω. With most 1.7MHz ceramic filters and many crystal filters, no impedance matching network is necessary. For applications requiring wideband IF filtering, such as DECT, external LC filters are used (see Figure 1). To achieve optimum linearity of the log signal strength indicator, there must be a 6dB(v) insertion loss between the first and second IF stages. If the IF filter or interstage network does not cause 6dB(v) insertion loss, a fixed or variable resistor can be added between the first IF output (Pin 16) and the interstage network. 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 9 phase relationship to the internal signal, drives the other port of the multiplier cell. Overall, the IF section has a gain of 9dB. For operation at intermediate frequency at 1.7MHz. Special care must be given to layout, termination, and interstage loss to avoid instability. The demodulated output (DATA) of the quadrature is a voltage output. This output is designed to handle a minimum bandwidth of 6kHz. This is designed to demodulate wideband data, such as in DECT applications. A Receive Signal Strength Indicator () completes the circuitry. The output range is greater than 9dB and is temperature compensated. This log signal strength indicator exceeds the criteria for AMPS or TACS cellular telephone, DECT and RCR-8 cordless telephone. This signal drives an internal op amp. The op amp is capable of rail-to-rail output. It can be used for gain, filtering, or nd-order temperature compensation of the, if needed. NOTE: db(v) = log V OUT /V IN 1997 Nov 7 15

16 SO: plastic small outline package; leads; body width 7.5 mm SOT Nov 7 16

17 DEFINITIONS Data Sheet Identification Product Status Definition Objective Specification Preliminary Specification Product Specification Formative or in Design Preproduction Product Full Production This data sheet contains the design target or goal specifications for product development. Specifications may change in any manner without notice. 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. 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. Philips Semiconductors 811 East Arques Avenue P.O. Box 349 Sunnyvale, California Telephone Philips Semiconductors and Philips Electronics North America Corporation register eligible circuits under the Semiconductor Chip Protection Act. Copyright Philips Electronics North America Corporation 1994 All rights reserved. Printed in U.S.A Nov 7 17