r GaAs Abrupt Varactor Diodes c Ne ee Alpha CVE7800 Series Features Low Series Resistance High Q Ke a @ Low Capacitance Values for Applications at > Millimeter Wave Frequencies @ Available in Ceramic Packages with Low Parasitics and Also in Die Form Description Maximum Ratings Gallium arsenide abrupt junction varactor diodes changes capacitance as a function of applied reverse Reverse Voltage, Vr: 25V bias voltage, following the square root low (gamma Forward Current, IF: 100 mA = 0.5). The high electron mobility of gallium arsenide Power Dissipation at 25C: 250 mW translates into a very low series resistance and very ; Operating Temperature: 55 to 150C high Q for the gallium arsenide varactor. For example, Qofagallium arsenide abrupt junction varactor is two Storage Temperature: 65 to 200C to three times higher than its silicon counterpart. However, in certain applications the gallium arsenide varactor exhibits a higher surface noise, in comparison to an equivalent silicon varactor. Electrical Specifications Reverse Breakdown Voltage, Van (10 wA): 25V Min Reverse Leakage Current, IR (20V): 100 nA Maximum Junction Capacitance Ratio, Cy (0)/Cy (25): 3.7 Min Junction Capacitance Series Resistance! q! Outline Available Cy @ OV (pF) Rg @ 4V, 50 MHz (2) AV, 50 MHz Chip Package Part Number Min Max Max Min Number Outlines? CVE7800-06 0.4 0.6 1.1 15,000 150-808 023-011, 290-001 CVE780012 0.6 0.8 0.9 12,000 150-808 023-011, 290-001 CVE7800-18 0.8 1.0 0.8 10,000 150-807 023-011, 290-001 CVE780024 1.0 1.5 0.7 8,500 150-807 023-011, 290-001 CVE7800-30 1.5 2.0 0.6 7,000 150-807 023-011, 290-001 CVE7800-36 2.0 2.5 0.55 6,000 150-807 023-011, 290-001 CVE780042 2.5 3.0 0.5 5,000 150-807 023-011, 290-001 CVE7800-48 3.0 4.0 0.5 4,000 150-807 023-011, 290-001 1. The measured values of figure of merit, Q, and series resistance, Rg, for a varactor diode are sensitive to the measurement method and set-up. The test set-up and test conditions used at Alpha are specified in the Application Notes section. 2. For availability and delivery on other package Styles, please consult the factory. ALPHA INDUSTRIES, ING. * 20 SYLVAN ROAD, WOBURN, MA 01801 4-22 TEL: (617) 935-5150 FAX: (617) 824-4579; _GaAs Abrupt Varactor Diodes CVE7800 Series Performance Data 10.0 c L. & 8 5 1.0 = CVE7800-48 E CVE7800-42 3 c CVE7800-36 a F CVE7800-30 oO L CVE7800-24 CVE7800-18 T CVE7800-12 CVE7800--06 0.1 1 Jo 1 a | | 1 10 Reverse Bias Voltage (V) R+ Capacitance vs. Voltage Package Outlines GaAs diodes are available as dice and in a variety of package outlines. Consult the factory for availability. The packages are designed to facilitate the handling of devices and circuit placement. However, the package may influence the devices performance. Please refer to Outline Drawings section for catalog package outlines, their characteristics, and their effect on electrical parameters of the diode. Ordering Information To order an unpackaged die, simply identify the desired die by the part numbers as listed in the table of electrical specifications. To order a packaged diode, simply append the package part number to the die part number. For example, CVE7800-06-023-011 represents the varactor diode formed by assembling CVE780006 die in a 023-011 package outline. 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 o LcLitlits ts tititriititiii 0 2 4 6 8 10 12 14 16 18 20 22 24 RS (Ohms) Reverse Bias Voltage (V) Series Resistance vs. Voltage Abrupt Varactor Diodes for High Reliability Applications Please refer to Reliability section for recommended quality assurance and inspection sequences for varactor diodes. This section also covers package outlines available for high reliability applications and simplified ordering instructions. Mathematical Model Please refer to Application Notes section for a mathematical model for a varactor diode. ALPHA INDUSTRIES, INC. * 20 SYLVAN ROAD, WOBURN, MA 01801 TEL: (617) 935-5150 FAX: (617) 824-4579 4-23