Schottky Barrier Diode Quads for Double Balanced Mixers Technical Data 5082-2830 Features Outline E4 • Small Size Eases Broad Band Designs • Tight Match Improves Mixer Balance • Improved Balance over Temperature • Rugged Design CP = 0.07 pF diagonal CP = 0.09 pF adjacent 0.56 (0.022) 0.46 (0.018) 2.79 (0.110) 2.29 (0.090) Description/Applications This matched diode quad uses a monolithic array of Schottky diodes interconnected in ring configuration. The relative proximity of the diode junction on the wafer assures uniform electrical characteristics and temperature tracking. 4.06 (0.160) 3.56 (0.140) 1.27 (0.05) MAX. 0.64 (0.025) MAX. 0.15 (0.006) 0.10 (0.004) These diodes are designed for use in double balanced mixers, phase detectors, AM modulators, and pulse modulators requiring wideband operation and small size. the low barrier diodes allow for optimum mixer noise figure at lower than conventional local oscillator levels. the wider dynamic range of the medium barrier diodes allows for better distortion performance. Note: For new designs, the HSMS-820X series of surface mount microwave diodes are recommended. 5965-8848E DIMENSIONS IN MILLIMETERS AND (INCHES). Maximum Ratings Operating and Storage Temperature Range E4 ............................................................................. -65°C to +125°C DC Power Dissipation ............................................... 75 mW per Juction Derated linearly to zero at maximum rated temperatures (measured in infinite heat sink at TCASE = 25°C). Soldering Temperature E4 ............................................................................. 220°C for 10 sec These diodes are ESD sensitive. Handle with care to avoid static discharge through the diode. 3-62 Typical Parameters Electrical Specifications at TA = 25°C Part Number 5082- Package Barrier Maximum Capacitance CM (pF) 2830 E4 Medium 0.5 Typ. Test Conditions Maximum Measured Capacitance Difference ∆ CM (pF) Maximum VF Difference ∆ VF (mV) Maximum Dynamic Resistance RD (Ω) 0.20 20 12 VR = 0 f = 1 MHz Package Characteristics The HP outline E4 package is designed for MIC, Microstrip, and Stripline use from dc through C-Band. The leads provide a good continuity of transmission line impedance to the monolithic diode array. The leads are tin plated copper. Dynamic and Series Resistance Schottky diode resistance may be expressed as series resistance, RS, or as dynamic ressitance, RD. These two terms are related by the equation RD = RS = Rj where Rj is the resistance of the junction. Junction resistance of a diode with DC bias is quite accurately calculated by Rj = 26/IB SPICE Parameters Parameter Units 5082-2830 BV CJ0 EG IBV IS N RS PB PT M V pF eV A A 10 4 0.69 10E-5 2 x 10E - 10 1.08 6 0.65 2 0.5 Ω V IF = 5 mA between Adjacent Leads where IB is the bias current in milliamperes. The series resistance is independent of current. The dynamic resistance is more easily measured. If series resistance is specified, it is usually obtained by subtracting the calculated junction resistance from the measured dynamic resistance. 3-63 0.40 IF = 1 mA Measured between Adjacent Leads calculated by the formulas given below. In a quad, the diagonal capacitance is the capacitance between points A and B as shown in figure below. The diagonal capacitance is calculated using the following formula C1 x C2 C3 x C4 CDIAGONAL = _______ + ______ C1 + C2 C3 + C4 A Quad Capacitance Capacitance of Schottky diode quads is measured using an HP4271 LCR meter. This instrument effectively isolates individual diode branches from the others, allowing accurate capacitance measurement of each branch or each diode. The conditions are: 20 mV R.M.S. voltage at 1 MHz. HP defines this measurement as “CM”, and it is equivalent to the capacitance of the diode by itself. The equivalent diagonal and adjacent capacitances can then be Forward Voltage VF (V) C1 C3 C2 C4 C B The equivalent adjacent capacitance is the capacitance between points A and C in figure below. This capacitance is calculated using the following formula 1 CADJACENT = C1 + ____________ 1 1 1 –– + –– + –– C2 C3 C4