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RF COMMUNICATIONS PRODUCTS
SA612A Double-balanced mixer and oscillator
Product specification Replaces data of September 17, 1990 IC17 Data Handbook 1997 Nov 07
Philips Semiconductors
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
SA612A
DESCRIPTION
The 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 SA612A excellent for battery operated equipment. Networking and other communications products can benefit from very low radiated energy levels within systems. The 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)
· 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 -40 to +85°C -40 to +85°C
ORDER CODE SA612AN SA612AD
DWG # 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
1997 Nov 07
2
853-0391 18662
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
SA612A
ABSOLUTE MAXIMUM RATINGS
SYMBOL VCC TSTG TA PARAMETER Maximum operating voltage Storage temperature Operating ambient temperature range SA612A RATING 9 -65 to +150 -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 k pF k
DESCRIPTION OF OPERATION
The 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 SA612A is designed for optimum low power performance. When used with the SA614A as a 45MHz cordless phone/cellular
radio 2nd IF and demodulator, the 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 SA612A should be appropriately scaled.
1997 Nov 07
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Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
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
1997 Nov 07
4
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
SA612A
Besides excellent low power performance well into VHF, the 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 1.5k 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
1997 Nov 07
5
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
SA612A
12pF
CT*
5
5
612A
CFU455 or Equivalent
612A Filter K&L 38780 or Equivalent *CT matches 3.5k 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
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Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
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
1997 Nov 07
7
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
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
1997 Nov 07
8
Philips Semiconductors
Product specification
Double-balanced mixer and oscillator
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
1997 Nov 07
9
Philips Semiconductors
Product specification
Double-balanced mixer oscillator
SA612
SO8: plastic small outline package; 8 leads; body width 3.9mm
SOT96-1
1997 Nov 07
10
Philips Semiconductors
Product specification
Double-balanced mixer oscillator
SA612
DIP8: plastic dual in-line package; 8 leads (300 mil)
SOT97-1
1997 Nov 07
11
Philips Semiconductors
Product specification
Double-balanced mixer oscillator
SA612
DEFINITIONS
Data Sheet Identification
Objective Specification
Product Status
Formative or in Design
Definition
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.
Preliminary Specification
Preproduction Product
Product Specification
Full Production
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 3409 Sunnyvale, California 940883409 Telephone 800-234-7381 © Copyright Philips Electronics North America Corporation 1997 All rights reserved. Printed in U.S.A.
Philips Semiconductors
1997 Nov 07 12