Digital Attenuator, 1 Bit, Variable Step, 10 - 20 dB, DC - 3000 MHz AT-246 AT-246 Digital Attenuator, 1 Bit, Variable Step 10 - 20 dB, DC - 3000 MHz Features • • • • • • MSOP-8 Variable Step (10 - 20 dB) with an External Resistor Matched Input and Output Low Intermodulation Product: +53 dBm IP3 Low DC Power Consumption: 50 µW Low Cost, Low Profile MSOP 8 Plastic Package Tape and Reel Packaging Available R .0 1 0 ID P IN 0 .0 0 7 0 .1 9 3 Description .0 2 0 M/A-COM’s AT-246 is a GaAs MMIC matched 1 bit attenuator in a low cost plastic MSOP-8 package. It is designed to be a building block for a single step attenuator by placing a resistor across RF1-RF2. Attenuation levels of 10 to 20 dB with flat response are achievable from DC to 3 GHz. The AT-246 is ideally suited for circuits where fast switching, very low power consumption and low intermodulation products are required. Typical applications include gain/level and sensitivity control in radio and cellular equipment, wireless LAN’s, GPS equipment and other gain/level control circuits. The AT-246 is fabricated using a mature 1-micron gate length GaAs MESFET process. The process features full chip passivation for increased performance and reliability. 1 4X 12° 0 .1 1 8 .0 2 0 0 .0 2 5 6 0 .0 2 1 5 0 .1 1 8 4X 12° 3° 0 .0 4 0 0 .0 3 4 0 .0 0 8 0 .0 1 3 1. Dimensions are in inches. Ordering Information Part Number Package AT-246 PIN MSOP-8 Lead Plastic AT-246TR Forward Tape and Reel 1 1. If specific reel size is required, consult factory for part number assignment. Electrical Specifications: TA = +25°C Parameter Reference Insertion Loss Attenuation Flatness VSWR 1 dB Compression Trise, Tfall Ton, Toff Transients IP2 IP3 1. 2. 1, 2 Test Conditions DC - 3.0 GHz DC - 1.5 GHz 1.5 - 3.0 GHz DC - 3.0 GHz Input Power 50 MHz Input Power 500 MHz 10% to 90% RF, 90% to 10% RF 50% Control to 90% RF, Control to 10% RF In-band Measured Relative 50 MHz 500 MHz to Input Power2 Measured Relative 50 MHz 2 500 MHz to Input Power Units dB dB dB Min. dBm dBm µS µS mV dBm dBm dBm dBm Typ. 0.8 ±0.5 ±1.5 1.3:1 24 30 20 23 25 54 73 45 55 Max. 1.0 ±1.0 ±2.0 All measurements in a 50Ω system unless otherwise specified. Loss varies at 0.003 dB/°C. For two-tone Input Power up to +5 dBm. V2.00 M/A-COM Division of AMP Incorporated Q North America: Tel. (800) 366-2266, Fax (800) 618-8883 Q Asia/Pacific: Tel.+85 2 2111 8088, Fax +85 2 2111 8087 Q Europe: Tel. +44 (1344) 869 595, Fax+44 (1344) 300 020 www.macom.com AMP and Connecting at a Higher Level are trademarks. Specifications subject to change without notice. Digital Attenuator, 1 Bit, Variable Step, 10 - 20 dB, DC - 3000 MHz 1 Absolute Maximum Ratings Parameter AT-246 Functional Schematic Absolute Maximum Input Power RF1 50 MHz RF2 +27 dBm 500 - 2000 MHz +33 dBm Control Voltage +5V, -8.5V Operating Temperature -40°C to +85°C Storage Temperature -65°C to +150°C 1. Rstep GND GND 20dB Exceeding any one or a combination of these limits may cause permanent damage. PIN 1 PIN Configuration PIN No. Function Description 1 GND RF Ground 2 V1 Bit Control 3 V2 Bit Control 4 GND RF Ground 5 RF2 RF in/out 6 GND RF Ground 7 GND RF Ground 8 RF1 RF in/out GND V1 V2 GND Note: Rstep value is selected for desired attenuation level. The usable range is 50Ω to OPEN to achieve 10 - 20 dB attenuation with >15 dB Return Loss. Truth Table V1 0 1 V2 1 0 Attenuation (dB) Reference I.L. Step “0” = 0 ±0.2V “1” = -5 ±0.2V Typical Performance Curves Insertion Loss vs. Frequency 25 +85° C 1 Attenuation (dB) Insertion Loss (dB) 1.2 +25° C 0.8 -40° C 0.6 0.4 0.2 0 RStep=OPEN 20 RStep= 820 Ω 15 RStep=180 Ω 10 RStep=51 Ω 5 0 0 1.5 ATTENUATION FREQUENCY Attenuation vs. vs Frequency 0.5 1 1.5 2 FREQUENCY (GHz) 2.5 3 VSWR vs Frequency 0 1 2 FREQUENCY (GHz) 3 4 Recommended Layout 1.4 VSWR PIN 1 1.3 Step Set Resistor Worst Case 1.2 1.1 1 0 1 2 FREQUENCY (GHz) 3 4 V2.00 M/A-COM Division of AMP Incorporated Q North America: Tel. (800) 366-2266, Fax (800) 618-8883 Q Asia/Pacific: Tel.+85 2 2111 8088, Fax +85 2 2111 8087 Q Europe: Tel. +44 (1344) 869 595, Fax+44 (1344) 300 020 www.macom.com AMP and Connecting at a Higher Level are trademarks. Specifications subject to change without notice.