RF2420 9 PROGRAMMABLE ATTENUATOR Typical Applications • Power Control in Communication Systems • Commercial and Consumer Systems • CMOS Compatible Programmable • Portable Battery-Powered Equipment Attenuators Product Description -A- 0.018 0.014 0.393 0.386 0.050 8° MAX 0° MIN Optimum Technology Matching® Applied GaAs HBT Si Bi-CMOS SiGe HBT ü 0.068 0.053 0.244 0.229 0.034 0.016 Si BJT 0.008 0.004 0.009 0.007 NOTES: 1. Shaded lead is Pin 1. 2. All dimensions are excluding mold flash. 3. Lead coplanarity - 0.005 with respect to datum "A". 9 ATTENTUATORS AND SWITCHES 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. 0.157 0.150 Package Style: SOIC-16 GaAs MESFET Si CMOS Features • Single 3V to 6V Supply RF IN 1 16 G2 • 0dB to 44dB Attenuation Range 15 G4 • 4dB Insertion Loss 14 G8 • 5-bit Digitally Controlled Attenuation 2 dB VDD 2 VDD 3 4 dB VDD 4 13 GND • DC to 950MHz Frequency Range 8 dB VDD 5 VDD 6 12 GND 10 dB VDD 7 11 G10 10 G20 20 dB VDD 8 9 RF OUT Functional Block Diagram Rev A6 010720 • Digitally Controlled Power Down Mode Ordering Information RF2420 RF2420 PCBA Programmable Attenuator Fully Assembled Evaluation Board RF Micro Devices, Inc. 7628 Thorndike Road Greensboro, NC 27409, USA Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com 9-9 RF2420 Absolute Maximum Ratings Parameter Supply Voltage RF Input Power Operating Ambient Temperature Storage Temperature Rating Unit -0.5 to +7.0 +17 -40 to +85 -40 to +150 VDC dBm °C °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). Specification Min. Typ. Max. Unit Condition Frequency Range DC to 950 MHz T=25°C and 5V at 420MHz Tuning of bypass capacitors is required for shifting the center frequency. See the evaluation board schematic for details. Insertion Loss Attenuation Range Gain Flatness 3dB Bandwidth 4 0 to 44 Parameter Overall 6 3 500 50 dB dB dB MHz MHz In any 50MHz band, at max attenuation At 26dB attenuation At maximum attenuation Input Input Impedance Input VSWR Input 1dB Compression +13 50 1.2:1 +15 Ω 1.5:1 dBm Attenuation ATTENTUATORS AND SWITCHES 9 Attenuation Settings Accuracy 2, 4, 8, 10, 20 ±0.5 ±1.0 dB dB dB CMOS Level, 5 bits 2dB step 4dB through 20dB steps V V mA ns Voltage Supplied to input Voltage Supplied to input Into each control line dBc dBc Ω With 0dBm output in each of 2 tones V V mA mA Specifications Operating Limits Operating Power Down Attenuation Control Attenuation “ON” Voltage Attenuation “OFF” Voltage Current Response Time 2.5 VDD 0.4 <10 0.3 1.0 Output IM3 Harmonic Output Output Impedance Output VSWR -30 -40 50 1.2:1 1.5:1 Power Supply Voltage Current 9-10 5 3 to 6 4 0.4 8 0.75 Rev A6 010720 RF2420 Pin 1 Function RF IN 2 VDD 3 4 5 6 7 8 9 VDD VDD VDD VDD VDD VDD RF OUT Description 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. Interface Schematic RF IN 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. Same as pin 2. Same as pin 2. Same as pin 2. Same as pin 2. Same as pin 2. Same as pin 2. RF Output. Same as pin 1. Pin 1 and 9 are interchangeable. RF OUT G20 11 G10 12 13 14 GND GND G8 15 G4 16 G2 Rev A6 010720 Control pin for the 20dB attenuator. This pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. Control pin for the 10dB attenuator. This pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. Ground. 9 Gxx ATTENTUATORS AND SWITCHES 10 Same as pin 10. Ground. Control pin for the 8dB attenuator. This pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. Control pin for the 4dB attenuator. This pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. Control pin for the 2dB attenuator. This pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. Same as pin 10. Same as pin 10. Same as pin 10. 9-11 RF2420 Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) P1 P2 P2-1 1 G2 P2-2 2 G4 P2-3 3 G8 P2-4 4 G10 P2-5 5 G20 NC 6 NC 7 NC P1-3 1 2 GND 3 VDD P2-1 RF IN 50 Ω µstrip J1 C9 100 pF C1 100 pF 1 SMA 16 C8 100 pF 15 2 GND 3 10 4 dB 14 P2-3 C2 120 pF 4 13 C7 100 pF 8 dB 5 Note: Series resonant at F0; place C2 midway between pin 2 and pin 8 12 P2-4 6 10 dB 7 9 P2-2 2 dB 8 9 NC NC 11 C6 100 pF 10 P2-5 20 dB ATTENTUATORS AND SWITCHES P1-3 8 9 C5 100 pF C3 10 µF RF OUT 2420400B C4 100 pF 9-12 50 Ω µstrip J2 SMA Rev A6 010720 RF2420 Evaluation Board Layout Board Size 2.020” x 2.020” Board Thickness 0.031”, Board Material FR-4 ATTENTUATORS AND SWITCHES 9 Rev A6 010720 9-13 RF2420 ATTENTUATORS AND SWITCHES 9 9-14 Rev A6 010720