Obsolescence Notice This product is obsolete. This information is available for your convenience only. For more information on Zarlink’s obsolete products and replacement product lists, please visit http://products.zarlink.com/obsolete_products/ THIS DOCUMENT IS FOR MAINTENANCE PURPOSES ONLY AND IS NOT RECOMMENDED FOR NEW DESIGNS ADVANCE INFORMATION DS3607 - 2.0 SL523 100MHz DUAL WIDEBAND LOG AMPLIFIER The SL523B and C are wideband amplifiers for use in successive detection logarithmic IF strips operating at centre frequencies between 10 and 100MHz They are pin compatible with the SL521 series of logarithmic amplifiers and comprise two amplifiers internally connected in cascade Small signal voltage gain is 24dB and an internal detector with an accurate logarithmic characteristic over a 20dB range produces a maximum Output of 2.1 mA. A strip of SL523s can be directly coupled and decoupling is provided on each amplifier RF limiting occurs at an input voltage of 25mV RMS but the device will withstand input voltages up to 1 8V RMS without damage The device is also available as the 5962-89803 which has guaranteed operation over the full Military Temperature Range and is screened to MIL-STD-883 Class B. Data is available separately. CM8 Fig.1 Pin connections (view from beneath) FEATURES QUICK REFERENCE DATA ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Small Size/Weight Low Power Consumption Readily Cascadable Accurate Logarithmic Detector Characteristic ABSOLUTE MAXIMUM RATINGS (Non-simultaneous) Storage temperature range Operating temperature range Thermal resistance Chip-to-ambient Chip-to-case Maximum instantaneous voltage at video output Supply voltage -65°C to +150°C -55°C to +125°C 200°C/W 52°C/W Small Signal Voltage Gain: 24dB Detector Output Current: 21mA Noise Figure: 4dB Frequency Range: 10-100MHz Supply Voltage +6V Supply Current 30mA ORDERING INFORMATION SL523 B CM SL523 C CM SL523 CB CM 5962-89803 (SMD) +12V +9V Fig.2 Circuit diagram (one amplifier) SL523 ELECTRICAL CHARACTERISTICS These characteristics are guaranteed over the following condltions (unless otherwise stated) Ambient temperature = 22°C ± 2°C; Source impedance = 10Ω; Supply voltage = +6V; Load impedance = 8pF; Frequency = 60MHz; DC connection between Pin 6 and 7 Characteristic Small signal voltage gain Small signal voltage gain Gain variation (set of 8) Upper cut-off frequency Lower cut-off frequency Propagation delay Maximum rectified video output current Maximum input signal before overload Noise figure Supply current Maximum RF output voltage Circuits Value Min. Typ. Max. B C B C 22.6 22 22 21.4 25.4 26 26 26.6 0.75 B, C B, C B, C B C B, C 120 24 24 24 24 0.5 150 10 4 2.1 2.1 1.9 B C B, C 25 23 4 30 30 1.2 5.25 36 38 1.9 1.8 1.8 15 2.3 2.4 Units dB dB dB dB dB MHz MHz ns mA mA V RMS dB mA mA V p-p Conditions Frequency = 30MHz Frequency = 60MHz Frequency = 60MHz See note below Source impedance 450Ω Note:- Overload occurs when the input signal reaches a level sufficient to forward bias the base-collector junction to the input transistor on peaks OPERATING NOTES The amplifier is designed to be directly coupled (seeFig.5) The fourth stage in an untuned cascade will give full output on the broad band noise generated by the first stage. Noise may be reduced by inserting a single tuned circuit in the chain As there is a large mismatch between stages a simple shunt or series circuit cannot be used The network chosen must give unity voltage gain at resonance to avoid distorting the log law The typical value for input impedance is 500Ω in parallel with 5pF and the output impedance is typically 30Ω. Although a 1nF supply line decoupling capacitor is included in the can an extra capacitor is required when the amplifiers are cascaded Minimum values for this capacitor are: 2 stages - 3nF, 3 or more stages 30nF In cascades of 3 or more stages care must be taken to avoid oscillations caused either by inductance common to the input and output earths of the strip or by feedback along the common video line The use of a continuous earth plane will avoid earth inductance problems and a common base amplifier in the video line isolating the first two stages as shown in Fig 6 will eliminate feedback on the video line Fig.3 Rectified output current v. input signal (typical) Fig.4 Voltage gain v. frequency (typical) SL523 Fig.5 Simple log. IF strip Fig.6 Wide dynamic range log. IF strip Fig.7 Wideband logarithmic amplifier SL523 TYPICAL PERFORMANCE Table 1 Stage gains of SL523 used in performance tests The input v output characteristic (Fig.8a) is calibrated at 10dB/cm in the X axis and 1V/cm in the Y axis 80dB of dynamic range was attained The error characteristic (Fig 8b) is calibrated at 10dB/cm in the X axis and 1dB/cm in the Y axis; this shows the error between the log input v. output characterisitc and a mean straight line and shows that a dynamic range of 80dB was obtained with an accuracy of ±0.5dB As a comparison, the log amplifier of Fig 7 was constructed with randomly selected SL521 Bs (two SL521 Bs replacing each SL523B). Again, a dynamic response of 80dB was obtained (Fig 9a) with an accuracy of 1 0 75dB (Fig.9b) Bandwidth curves are shown in Figs.8c and 9c, where the amplitude scale is 2dB/cm, with frequency markers at 10MHz intervals from 20 to 100MHz Using SL523Bs (Fig.8c), the frequency response at 90MHz is 4dB down on maximum and there is a fall-off in response after 50MHz Fig 9c shows that the frequency response of the amplifier falls off more gradually after 40MHz but again the response at 90MHz is 4dB down on maximum These tests show that the SL523 is a very successful dual stage log amplifier element and, since it is pin-compatible with the SL521 enables retrofit to be carried out in existing log amplifiers It will be of greatest benefit however, in the design of new log amplifiers, enabling very compact units to be realised with a much shorter summation line Fig.8a Input/output Fig.9a Input/output Fig.8b Error curve Fig.9b Error curve Fig.8c Frequency response, detected output Fig.9c Frequency response, detected output Fig.8 Characteristics of circuit shown in Fig 7 using SL523Bs Fig.9 Characteristics of circuit shown in Fig 7 using SL523Bs Unselected SL523B devices were tested in a wideband logarithmic amplifier. described in RSRE Memo No 3027 and shown in Fig 7 The amplifier consists of six logarithmic stages and two ‘lift’ stages, giving an overall dynamic range of greater than 80dB The response and error curves were plotted on an RHG Log Test Set and bandwidth measurements were made with a Telonic Sweeper and Tektronix oscilloscope Fig 8 shows the dynamic range error curve and f requency response obtained. The stage gains of the SL523 devices used were as shown in Table 1 Stages fo (MHz) Gain (dB) 1 2 3 Lift 60 60 60 60 24.1 23 24.089 23.888 24.086 Max. Deviation (dB) 0.235 SL523 SL523 HEADQUARTERS OPERATIONS GEC PLESSEY SEMICONDUCTORS Cheney Manor, Swindon, Wiltshire SN2 2QW, United Kingdom. Tel: (0793) 518000 Fax: (0793) 518411 GEC PLESSEY SEMICONDUCTORS P.O. Box 660017 1500 Green Hills Road, Scotts Valley, California 95067-0017, United States of America. Tel: (408) 438 2900 Fax: (408) 438 5576 CUSTOMER SERVICE CENTRES • FRANCE & BENELUX Les Ulis Cedex Tel: (1) 64 46 23 45 Fax : (1) 64 46 06 07 • GERMANY Munich Tel: (089) 3609 06-0 Fax : (089) 3609 06-55 • ITALY Milan Tel: (02) 66040867 Fax: (02) 66040993 • JAPAN Tokyo Tel: (03) 5276-5501 Fax: (03) 5276-5510 • NORTH AMERICA Scotts Valley, USA Tel (408) 438 2900 Fax: (408) 438 7023. • SOUTH EAST ASIA Singapore Tel: (65) 3827708 Fax: (65) 3828872 • SWEDEN Stockholm, Tel: 46 8 702 97 70 Fax: 46 8 640 47 36 • UK, EIRE, DENMARK, FINLAND & NORWAY Swindon Tel: (0793) 518510 Fax : (0793) 518582 These are supported by Agents and Distributors in major countries world-wide. GEC Plessey Semiconductors 1994 This publication is issued to provide information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. The Company reserves the right to alter without prior knowledge the specification, design or price of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to the Company's conditions of sale, which are available on request. 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Purchasers of products are also hereby notified that the use of product in certain ways or in combination with Zarlink, or non-Zarlink furnished goods or services may infringe patents or other intellectual property rights owned by Zarlink. This publication is issued to provide information only and (unless agreed by Zarlink in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. The products, their specifications, services and other information appearing in this publication are subject to change by Zarlink without notice. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user’s responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. Manufacturing does not necessarily include testing of all functions or parameters. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to Zarlink’s conditions of sale which are available on request. Purchase of Zarlink’s I2C components conveys a licence under the Philips I2C Patent rights to use these components in and I2C System, provided that the system conforms to the I2C Standard Specification as defined by Philips. Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc. Copyright Zarlink Semiconductor Inc. All Rights Reserved. TECHNICAL DOCUMENTATION - NOT FOR RESALE