RF2420 PROGRAMMABLE ATTENUATOR Typical Applications Power Control in Communication Systems CMOS Compatible Programmable Attenuators Commercial and Consumer Systems Portable Battery-Powered Equipment Product Description The RF2420 is a multistage monolithic programmable attenuator. The device is built using an advanced Gallium Arsenide process technology and has an attenuation programmability over a 44dB range in 2dB steps. The attenuation is set by five bits of digital data. The input and output of the device have a low VSWR 50Ω match. This unit is intended for use in systems that require RF transmit power control by digital means. Typical applications are in dual mode IS-54/55 compatible cellular transceivers and TETRA systems. No negative supply voltages are required. Optimum Technology Matching Applied Si BJT GaAs HBT GaAs MESFET Si Bi-CMOS SiGe HBT Si CMOS RF IN 1 VDD 2 VDD 3 VDD 4 VDD 5 2dB 4dB 8dB 16 G2 15 G4 14 G8 13 GND 12 GND 0.33 0.386 8 MAX 0 MIN Features 0.157 0.150 0.244 0.22 0.034 0.016 0.00 0.007 0.018 0.014 0.050 0.068 0.053 NOTES: 1. Shaded lead is Pin 1. 2. All dimensions are excluding mold flash. 3. Lead coplanarity - 0.005 with respect to datum "A". Package Style: SOIC-16 Single 3V to 6V Supply 0dB to 44dB Attenuation Range 4dB Insertion Loss 5-bit Digitally Controlled Attenuation Digitally Controlled Power Down Mode DC to 50MHz Frequency Range -A- 0.008 0.004 VDD 6 10 db 11 G10 VDD VDD 7 8 20 db 10 G20 RF OUT Ordering Information RF2420 Programmable Attenuator RF2420 PCBA Fully Assembled Evaluation Board Functional Block Diagram RF Micro Devices, Inc. 7628 Thorndike Road Greensboro, 2740, USA Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com -
Absolute Maximum Ratings Parameter Rating Unit Supply Voltage -0.5 to +7.0 V DC RF Input Power +17 dbm Operating Ambient Temperature -40 to +85 C Storage Temperature -40 to +150 C Caution! ESD sensitive device. RF Micro Devices believes the furnished information is correct and accurate at the time of this printing. However, RF Micro Devices reserves the right to make changes to its products without notice. RF Micro Devices does not assume responsibility for the use of the described product(s). Parameter Specification Min. Typ. Max. Unit Condition Overall T=25 C and 5V at 420MHz Frequency Range DC to 50 MHz Tuning of bypass capacitors is required for shifting the center frequency. See the evaluation board schematic for details. Insertion Loss 4 6 db Attenuation Range 0 to 44 db Gain Flatness 3 db In any 50MHz band, at max attenuation 3dB Bandwidth 500 MHz At 26dB attenuation 50 MHz At maximum attenuation Input Input Impedance 50 Ω Input VSWR 1.2:1 1.5:1 Input 1dB Compression +13 +15 dbm Attenuation Attenuation Settings 2, 4, 8, 10, 20 db CMOS Level, 5 bits Accuracy ±0.5 db 2dB step ±1.0 db 4dB through 20dB steps Attenuation Control Attenuation ON Voltage 2.5 V DD V Voltage Supplied to input Attenuation OFF Voltage 0.3 V Voltage Supplied to input Current 0.4 1.0 ma Into each control line Response Time <10 ns Output IM3-30 dbc With 0dBm output in each of 2 tones Harmonic Output -40 dbc Output Impedance 50 Ω Output VSWR 1.2:1 1.5:1 Power Supply Voltage 5 V Specifications 3 to 6 V Operating Limits Current 4 8 ma Operating 0.4 0.75 ma Power Down -10
Pin Function Description Interface Schematic 1 RF IN RF Input. This pin is not DC-blocked, and an external blocking capacitor is required. The value depends on the frequency used. The DC value on this pin is approximately equal to VDD. RF IN 2 VDD VDD supply connection. Bypassing is critical: To achieve maximum attenuation range the magnitude of the impedance at the operation frequency, as seen from the package pins, needs to be less than 0.5Ω. The DC source to the pin may be a logic driver gate to implement a Power Down function. 3 VDD Same as pin 2. 4 VDD Same as pin 2. 5 VDD Same as pin 2. 6 VDD Same as pin 2. 7 VDD Same as pin 2. 8 VDD Same as pin 2. RF OUT RF Output. Same as pin 1. Pin 1 and are interchangeable. RF OUT 10 G20 Control pin for the 20dB attenuator. This pin has an internal pull-down 11 G10 Control pin for the 10dB attenuator. This pin has an internal pull-down 12 GND Ground. 13 GND Ground. 14 G8 Control pin for the 8dB attenuator. This pin has an internal pull-down 15 G4 Control pin for the 4dB attenuator. This pin has an internal pull-down 16 G2 Control pin for the 2dB attenuator. This pin has an internal pull-down Gxx -11
Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) P2 P2-1 1 G2 P1 1 P2-2 2 G4 2 GND P2-3 3 G8 P1-3 3 VDD P2-4 4 G10 P2-5 5 G20 6 7 8 10 GND RF IN J1 SMA 50 Ωµstrip Note: Series resonant at F0; place C2 midway between pin 2 and pin 8 C1 C2 120 pf 1 2 3 4 5 6 2dB 4dB 8dB 10 db 16 15 14 13 12 11 C C8 C7 C6 P2-1 P2-2 P2-3 P2-4 P1-3 C3 10 µf 7 8 2420400B 20 db 10 C4 C5 P2-5 RF OUT J2 50 Ωµstrip SMA -12
Evaluation Board Layout Board Size 2.020 x 2.020 Board Thickness 0.031, Board Material FR-4-13
-14
This datasheet has been download from: www.datasheetcatalog.com Datasheets for electronics components.