GaAs 35 dB MMIC FET Voltage Variable Single Positive Control Attenuator 0.4–2.5 GHz AT002S3–12 Features 35 dB Range SOIC 8 Package Single Positive DC Bias Control Low Insertion Loss (< 1.7 dB @ 900 MHz) J1 Low Cost J2 Requires Single Fixed Positive 5 Volt Bias Description The AT002S3–12 GaAs FET MMIC bridge “T” attenuator provides 35 dB minimum absolute attenuation at 900 MHz. The key feature of this attenuator is the requirement of only one “positive” control voltage. On the RF terminals, blocking capacitors greater than 0.001 µf are necessary. Electrical Specifications at 25°C Operating Characteristics at 25°C Impedance 50 Ohms Nominal Switching Characteristics RISE, FALL (10/90% or 90/10% RF) ON, OFF (50% CTL to 90/10% RF) Video Feedthru 1.0 1.5 20 Insertion Loss 0.4 – 1.0 GHz 1.0 – 2.0 GHz 2.0 – 2.5 GHz 1.7 2.4 2.9 dB dB dB Max Max Max Attenuation Flatness 0.8–2.0 GHz 0–10 dB 11–20 dB 21–30 dB 31–Max Absolute Attenuation (V1=0V, VDD=5V) 0.4–0.6 0.6–1.0 1.0–1.5 1.5–2.0 2.0–2.5 30 35 30 27 25 dB dB dB dB dB Min Min Min Min Min Compression Point (900 MHz) Worst Case for all Attenuation States 0.1 dB –10 1.0 dB –3 VSWR (I/O)1,2 0.4 – 2.5 GHz 2.5:1 Max 1. For Insertion Loss and Absolute Attenuation States. 2. Better VSWR may be obtained by raising the +5V bias to +6V. Set control V1 to operate from 0 to 6V. 1–82 Powered by ICminer.com Electronic-Library Service CopyRight 2003 + 1.0 dB + 1.5 dB + 3.5 dB + 4.5 dB Control Voltages V1 (Low) V1 (High) 0 to 0.2V @ 35 µA Max +5V @ 30 µA Max Bias Voltage, VDD +5V @ 50 µA Max µs µs mV Typ Typ Typ Typ Typ Typ Typ dBm Typ dBm Typ ALPHA INDUSTRIES, INC. • 20 SYLVAN ROAD, WOBURN, MA 01801 TEL: (617) 935–5150 • FAX: (617) 824–4579 GaAs 35 dB MMIC FET Voltage Variable Single Positive Control Attenuator 0.4–2.5 GHz AT002S3–12 Typical Performance Data 30 2.4 25 2.0 20 –40°C dB dB 4 V1 = 2.55 V1 (Volts) +85°C 1.6 1.2 V1 = 2.75 15 V1 = 2.95 3 2 1 10 0.8 5 V1 = 2.35 V1 = 3.15 0.4 5 0.4 1.6 GHz 2.8 0.4 Insertion Loss vs. Frequency 1.6 GHz 2.8 Attenuation for a Given Vcontrol (by State) vs. Frequency 0 5 10 15 20 25 dB 35 Relative Attenuation vs. Control Voltage at 1.0 GHz 2.0 1.8 1.6 1.4 1.2 1.0 1.6 0.4 2.8 GHz VSWR vs. Frequency (Insertion Loss) Pin Out and Functional Schematic GND J2 GND Absolute Maximum Ratings GND CBL RF Input Power: 5 mW > 500 MHz Bias Voltage: +8V Control Voltage: CBL GND J1 VDD CBL supplied externally. ALPHA INDUSTRIES, INC. • 20 SYLVAN ROAD, WOBURN, MA 01801 TEL: (617) 935–5150 • FAX: (617) 824–4579 Powered by ICminer.com Electronic-Library Service CopyRight 2003 V1 < +8V (Do not allow control voltage to exceed VDD voltage.) Operating Temperature: –55°C to +125°C Storage Temperature: –65°C to +150°C Thermal Resistance: 25°C/W 1–83