NE612AN

Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A DESCRIPTION The NE/SA612A is a low-power VHF monolithic double-balanced mixer with on-board oscillator and voltage regulator. It is intended for low cost, low power communication systems with signal frequencies to 500MHz and local oscillator frequencies as high as 200MHz. The mixer is a “Gilbert cell” multiplier configuration which provides gain of 14dB or more at 45MHz. The oscillator can be configured for a crystal, a tuned tank operation, or as a buffer for an external L.O. Noise figure at 45MHz is typically below 6dB and makes the device well suited for high performance cordless phone/cellular radio. The low power consumption makes the NE/SA612A excellent for battery operated equipment. Networking and other communications products can benefit from very low radiated energy levels within systems. The NE/SA612A is available in an 8-lead dual in-line plastic package and an 8-lead SO (surface mounted miniature package). PIN CONFIGURATION D, N Packages INPUT A 1 INPUT B 2 GND 3 OUTPUT A 4 8 7 6 5 VCC OSCILLATOR OSCILLATOR OUTPUT B SR00098 Figure 1. Pin Configuration APPLICATIONS FEATURES • Low current consumption • Low cost • Operation to 500MHz • Low radiated energy • Low external parts count; suitable for crystal/ceramic filter • Excellent sensitivity, gain, and noise figure ORDERING INFORMATION DESCRIPTION 8-Pin Plastic Dual In-Line Plastic (DIP) 8-Pin Plastic Small Outline (SO) package (Surface-Mount) 8-Pin Plastic Dual In-Line Plastic (DIP) 8-Pin Plastic Small Outline (SO) package (Surface-Mount) • Cordless telephone • Portable radio • VHF transceivers • RF data links • Sonabuoys • Communications receivers • Broadband LANs • HF and VHF frequency conversion • Cellular radio mixer/oscillator TEMPERATURE RANGE 0 to +70°C 0 to +70°C -40 to +85°C -40 to +85°C ORDER CODE NE612AN NE612AD SA612AN SA612AD DWG # SOT97-1 SOT96-1 SOT97-1 SOT96-1 BLOCK DIAGRAM 8 V CC VOLTAGE REGULATOR OSCILLATOR 7 6 5 GROUND 1 2 3 4 SR00099 Figure 2. Block Diagram 1990 Sep 17 1 853-0391 00446 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A ABSOLUTE MAXIMUM RATINGS SYMBOL VCC TSTG TA PARAMETER Maximum operating voltage Storage temperature Operating ambient temperature range NE SA RATING 9 -65 to +150 0 to +70 -40 to +85 UNIT V °C °C AC/DC ELECTRICAL CHARACTERISTICS TA=25°C, VCC = 6V, Figure 3 SYMBOL VCC fIN fOSC PARAMETER Power supply voltage range DC current drain Input signal frequency Oscillator frequency Noise figured at 45MHz Third-order intercept point at 45MHz Conversion gain at 45MHz RIN CIN RF input resistance RF input capacitance Mixer output resistance (Pin 4 or 5) RFIN=-45dBm 14 1.5 3 1.5 TEST CONDITION LIMITS Min 4.5 2.4 500 200 5.0 -13 17 Typ Max 8.0 3.0 UNIT V mA MHz MHz dB dBm dB kΩ pF kΩ DESCRIPTION OF OPERATION The NE/SA612A is a Gilbert cell, an oscillator/buffer, and a temperature compensated bias network as shown in the equivalent circuit. The Gilbert cell is a differential amplifier (Pins 1 and 2) which drives a balanced switching cell. The differential input stage provides gain and determines the noise figure and signal handling performance of the system. The NE/SA612A is designed for optimum low power performance. When used with the NE614A as a 45MHz cordless phone/cellular radio 2nd IF and demodulator, the NE/SA612A is capable of receiving -119dBm signals with a 12dB S/N ratio. Third-order intercept is typically -15dBm (that’s approximately +5dBm output intercept because of the RF gain). The system designer must be cognizant of this large signal limitation. When designing LANs or other closed systems where transmission levels are high, and small-signal or signal-to-noise issues not critical, the input to the NE/SA612A should be appropriately scaled. 1990 Sep 17 2 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A TEST CONFIGURATION 0.5 to 1.3µH 22pF 5.5µH VCC 6.8µF 100nF 10nF 8 7 6 5 150pF OUTPUT 1nF 10pF 34.545MHz THIRD OVERTONE CRYSTAL 612A 1.5 to 44.2µH 330pF 1 47pF INPUT 220pF 100nF 0.209 to 0.283µH 2 3 4 120pF SR00101 Figure 3. Test Configuration 8 VCC 18k 6 7 25k BUFFER 1.5k 4 1.5k 5 BIAS BIAS 2 1 BIAS 1.5k 3 GND 1.5k SR00102 Figure 4. Equivalent Circuit 1990 Sep 17 3 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A Besides excellent low power performance well into VHF, the NE/SA612A is designed to be flexible. The input, output, and oscillator ports can support a variety of configurations provided the designer understands certain constraints, which will be explained here. The RF inputs (Pins 1 and 2) are biased internally. They are symmetrical. The equivalent AC input impedance is approximately 1.5k || 3pF through 50MHz. Pins 1 and 2 can be used interchangeably, but they should not be DC biased externally. Figure 5 shows three typical input configurations. The mixer outputs (Pins 4 and 5) are also internally biased. Each output is connected to the internal positive supply by a 1.5kΩ resistor. This permits direct output termination yet allows for balanced output as well. Figure 6 shows three single-ended output configurations and a balanced output. The oscillator is capable of sustaining oscillation beyond 200MHz in crystal or tuned tank configurations. The upper limit of operation is determined by tank “Q” and required drive levels. The higher the Q of the tank or the smaller the required drive, the higher the permissible oscillation frequency. If the required L.O. is beyond oscillation limits, or the system calls for an external L.O., the external signal can be injected at Pin 6 through a DC blocking capacitor. External L.O. should be 200mVP-P minimum to 300mVP-P maximum. Figure 7 shows several proven oscillator circuits. Figure 7a is appropriate for cordless phones/cellular radio. In this circuit a third overtone parallel-mode crystal with approximately 5pF load capacitance should be specified. Capacitor C3 and inductor L1 act as a fundamental trap. In fundamental mode oscillation the trap is omitted. Figure 8 shows a Colpitts varacter tuned tank oscillator suitable for synthesizer-controlled applications. It is important to buffer the output of this circuit to assure that switching spikes from the first counter or prescaler do not end up in the oscillator spectrum. The dual-gate MOSFET provides optimum isolation with low current. The FET offers good isolation, simplicity, and low current, while the bipolar circuits provide the simple solution for non-critical applications. The resistive divider in the emitter-follower circuit should be chosen to provide the minimum input signal which will assume correct system operation. 612A 612A 612A 1 INPUT 2 1 2 1 2 a. Single-Ended Tuned Input b. Balanced Input (For Attenuation of Second-Order Products) c. Single-Ended Untuned Input SR00103 Figure 5. Input Configuration 1990 Sep 17 4 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A 12pF CT* 5 5 612A CFU455 or Equivalent 612A Filter K&L 38780 or Equivalent *CT matches 3.5kΩ to next stage 4 4 a. Single-Ended Ceramic Filter b. Single-Ended Crystal Filter 5 5 612A 612A 4 4 c. Single-Ended IFT d.. Balanced Output SR00104 Figure 6. Output Configuration L1 C3 C2 XTAL 8 7 C1 6 5 8 7 6 5 8 7 6 5 612A 612A 612A 1 2 3 4 TC02101S 1 2 3 4 TC02111S 1 2 3 4 TC02121S a. Colpitts Crystal Oscillator (Overtone Mode) b. Colpitts L/C Tank Oscillator c. Hartley L/C Tank Oscillator SR00105 Figure 7. Oscillator Circuits 1990 Sep 17 5 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A 5.5µH +6V 0.10pF 10µF 0.1µF 1 8 2 612A 7 7pF 10pF TO BUFFER 3 6 1000pF 4 5 1000pF 0.06µH DC CONTROL VOLTAGE FROM SYNTHESIZER MV2105 OR EQUIVALENT 0.01µF 100k 2k 0.01pF 3SK126 2N918 2N5484 2pF TO SYNTHESIZER 100k 100k 330 1.0nF 0.01µF TO SYNTHESIZER SR00106 Figure 8. Colpitts Oscillator Suitable for Synthesizer Applications and Typical Buffers 1990 Sep 17 6 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A TEST CONFIGURATION 0.5 to 1.3µH 5.5µH VCC 6.8µF 100nF 10nF 1nF 22pF 44.545MHz THIRD OVERTONE CRYSTAL 5.6pF 8 7 6 5 612A 1 47pF INPUT 45MHz IN 220pF 100nF 0.209 to 0.283µH 2 3 4 SFG455A3 OR EQUIVALENT 455kHZ SR00107 Figure 9. Typical Application for Cordless/Cellular Radio 1990 Sep 17 7 Philips Semiconductors Product specification Double-balanced mixer and oscillator NE/SA612A 3.50 3.25 SUPPLY CURRENT 9mA) 3.00 2.75 2.50 2.25 2.00 1.75 1.50 –40 –30 –20 –10 0 10 20 30 40 TEMPERATURE OC 50 60 70 80 90 8.5V 6.0V 4.5V NOISE FIGURE (dB) 6.00 5.75 5.50 5.25 5.00 4.75 4.50 4.25 4.00 –40 –30 –20 –10 4.5V 6.0V 8.5V 0 10 20 30 40 50 TEMPERATURE OC 60 70 80 90 SR00108 SR00111 Figure 10. ICC vs Supply Voltage Figure 13. Noise Figure RF1 = 45MHz, IF = 455kHz, RF2 = 45.06MHz 20.0 19.5 19.0 CONVERSION GAIN (dB) 18.5 17.5 17.0 16.5 16.0 15.5 15.0 14.5 14.0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 IF OUTPUT POWER (dBm) 18.0 6.0V 8.5V 4.5V 0 20 3rd ORDER PRODUCT –20 FUND. PRODUCT –40 –60 TEMPERATURE OC SR00109 –80 –60 Figure 11. Conversion Gain vs Supply Voltage –40 –20 0 RF INPUT LEVEL (dBm) 20 SR00112 Figure 14. Third-Order Intercept and Compression –10.0 –10.5 INPUT INTERCEPT POINT (dBm) –11.0 –11.5 –12.0 –12.5 –13.0 –13.5 –14.0 –14.5 –15.0 –15.5 –16.0 –16.5 –17.0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 –17 –18 INTERCEPT (dBm) TEMPERATURE OC –10 –11 –12 –13 –14 –15 –16 SR00110 4 5 6 7 8 9 10 Figure 12. Third-Order Intercept Point VCC (VOLTS) SR00113 Figure 15. Input Third-Order Intermod Point vs VCC 1990 Sep 17 8