ARA05050 Reverse Amplifier with Step Attenuator Data Sheet - Rev 2.0 FEATURES · · · · · · · Low cost integrated monolothic GaAs amplifier with step attenuator Attenuation Range: 0-30 dB, adjustable in 2dB increments via a 4 wire parallel control Meets DOCSIS distortion requirements at +58dBmV output signal level Low distortion and low noise Low signal to noise ratio at all gain levels Frequency range: 5-100MHz 5 Volt operation APPLICATIONS · · · · · MCNS/DOCSIS Compliant Cable Modems CATV Interactive Set-Top Box OpenCable Set-Top Box Fiber Nodes Cable Modem Termination Systems (CMTS) S12 Package 28 Pin SSOP with Heat Slug PRODUCT DESCRIPTION The ARA05050 is a GaAs IC designed to provide the reverse path amplification and output level control functions in a CATV Set-Top Box or Cable Modem. It incorporates a digitally controlled precision step attenuator that is preceded by an ultra low noise amplifier stage, and followed by an ultra-linear output driver amplifier. This device is capable of meeting the MCNS/DOCSIS requirements for harmonic 4 Switch ARA05050 performance at a +58dBmV output level while requiring only a single polarity +5V supply. Both the input and the output are single-ended and matched to 75 Ohms. The precision attenuator provides up to 30 dB of attenuation in 2 dB increments. The ARA05050 is offered in a 28-pin SSOP package featuring a heat slug on the bottom of the package. Attenuation Control LPF Balun Upstream QPSK/16QAM Modulator RAM Clock Data Transmit Enable/Disable 5-42 MHz Microcontroller with Ethernet MAC MAC Clock ROM Data 44 MHz Diplexer 54-860 MHz DoubleConversion Tuner SAW Filter QAM Receiver with FEC 10Base-T Transceiver Figure 1. Cable Modem or Set Top Box Application Diagram 07/2001 RJ45 Connector ARA05050 RFOUT1 ATTIN ATTOUT RFIN2 30 dB, 2dB step digital attenuator section RFIN A1 A2 ISET1 16 dB 8 dB 4 dB 2 dB ISET2 Figure 2: Functional Block Diagram 1 N/C N/C 28 2 Bypass N/C 27 3 ATTIN ATTOUT 26 4 RFOUT1 ISET2 25 5 VREF1 RFIN2 24 6 ATTACG1 ATTACG2 23 7 ATTACG1 ATTACG2 22 8 ATTACG1 ATTACG2 21 ATTACG2 20 9 ATTACG1 10 RFIN VREF2 19 11 ISET1 RFOUT 18 12 VATT GND 17 13 16 dB 2 dB 16 14 8 dB 4 dB 15 Figure 3: Pin Out 2 Data Sheet - Rev 2.0 07/2001 RFOUT ARA05050 Table 1: Pin Description PIN N AME D ESC R IPTION PIN N AME 1 N/C No C onnecti on 15 4 dB 4 dB Attenuti on C ontrol Bi t 2 Bypass Internal bypass 16 2 dB 2 dB Attenuti on C ontrol Bi t 3 ATTIN Attenuator Input (2) 17 GND Ground 4 RFOUT1 Ampli fi er A1 Output and Supply 18 RFOUT Ampli fi er A2 Output and Supply 5 VREF1 Reference Voltage for Ampli fi er A1 19 VREF2 Reference Voltage for Ampli fi er A2 6 ATTACG1 Attenuator AC Ground 1 (3) 20 ATTACG2 Attenuator AC Ground 2 (3) 7 ATTACG1 Attenuator AC Ground 1 (3) 21 ATTACG2 Attenuator AC Ground 2 (3) 8 ATTACG1 Attenuator AC Ground 1 (3) 22 ATTACG2 Attenuator AC Ground 2 (3) 9 ATTACG1 Attenuator AC Ground 1 (3) 23 ATTACG2 Attenuator AC Ground 2 (3) 10 RFIN Ampli fi er A1 Input (4) 24 RFIN2 Ampli fi er A2 Input (4) 11 ISET1 Ampli fi er A1 C urrent Adjust (4) 25 ISET2 Ampli fi er A2 C urrent Adjust (4) 12 VATT Attenuator Supply 26 ATTOUT 13 16 dB 16 dB Attenuti on C ontrol Bi t 27 N/C No C onnecti on (1) 14 8 dB 82 dB Attenuti on C ontrol Bi t 28 N/C No C onnecti on (1) (1) D ESC R IPTION Attenuator Output (2) Notes: (1) All N/C pins should be grounded. (2) Pins should be AC-coupled. No external DC bias should be applied. (3) Pins should be AC-grounded. No external DC bias should be applied. (4) Pins should be grounded or pulled to ground through a resistor. No external DC bias should be applied. Data Sheet - Rev 2.0 07/2001 3 ARA05050 ELECTRICAL CHARACTERISTICS Table 2: Absolute Minimum and Maximum Ratings PAR AMETER MIN MAX U N IT 0 9 VD C Ampli fi er Reference Voltages (pi ns 5, 19) -2.5 VSUP 2 VD C RF P ower at A mpli fi er Inputs (pi ns 10, 24) - +60 dBmV Attenuator C ontrols (pi ns 13, 14, 15, 16) 0 6 V -55 +200 o C Solderi ng Temperature - 260 o C Solderi ng Ti me - 5 Analog Supply: VSUP (pi ns 4, 12, 18) Storage Temperature S ec Stresses in excess of the absolute ratings may cause permanent damage. Functional operation is not implied under these conditions. Exposure to absolute ratings for extended periods of time may adversely affect reliability. Notes: 1. Pins 3 and 26 should be AC-coupled. No external DC bias should be applied. 2. Pins 10, 11, 24 and 25 should be grounded or pulled to ground through a resistor. No external DC bias should be applied. 3. Pins 6, 7, 8, 9, 20, 21, 22 and 23 should be AC-grounded. No external DC bias should be applied. Table 3: Operating Ranges PAR AMETER MIN TYP MAX U N IT Ampli fi er Supply: VDD (pi ns 4, 18) 4.5 5 7 VD C Attenuator Supply: VATTN (pi n 12) VDD-0.5 5 7 VD C Attenuator C ontrols (pi ns 13, 14, 15, 16) 0 - 5.5 V Ampli fi er Reference Voltages (pi ns 5, 19) - 1.75 - VD C -40 25 85 C ase Temperature o C The device may be operated safely over these conditions; however, parametric performance is guaranteed only over the conditions defined in the electrical specifications. 4 Data Sheet - Rev 2.0 07/2001 ARA05050 Table 4: DC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PAR AMETER MIN TYP MAX U N IT Ampli fi er A1 C urrent (pi n 4) - 75 95 mA Ampli fi er A2 C urrent (pi n 18) - 100 130 mA Attenuator C urrent (pi n 12) - 8 - mA Total Power C onsumpti on - 0.92 1.2 W Table 5: AC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PAR AMETER MIN TYP MAX U N IT Gai n (10 MHz) 30 32 33 dB 0 dB attenuati on setti ng Gai n Flatness - 0.75 1.5 dB 5 to 100 MHz Gai n Vari ati on over Temperature - -0.006 - dB/°C 1.6 3.8 8.0 16.0 1.85 4.0 8.3 16.6 2.2 4.2 8.5 17.0 2nd Harmoni c D i storti on Level 5 MHz 25 MHz - -60 -63 3rd Harmoni c D i storti on Level 5 MHz 25 MHz - Attenuati on Steps 2 dB 4 dB 8 dB 16 dB C OMMEN TS dB 5 to 42 MHz (1), Monotoni c -55 -55 dB c +58 dBmV i nto 75 Ohms -63 -63 -60 -60 dB c +58 dBmV i nto 75 Ohms 78 - - dBmV 1 dB Gai n C ompressi on Poi nt - 70 - dBmV Noi se Fi gure - 1.7 2.5 dB 3rd Order Output Intercept Notes: (1) See Figures 5 and 6 for performance at higher frequencies. All specifications as measured in ANADIGICS test fixture. Data Sheet - Rev 2.0 07/2001 5 ARA05050 continued: AC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PAR AMETER MIN TYP MAX U N IT C OMMEN TS Output Noi se Power Acti ve / No Si gnal / Mi n. Atten. Set. Acti ve / No Si gnal / Max. Atten. Set. - - -37.6 -54.6 dBmV Any 160 kHz bandwi dth from 5 to 42 MHz Input Impedance - 75 - Ohms Input Return Loss - -20 -15 dB Output Impedance - 75 - Ohms Output Return Loss - -20 -15 dB 75 Ohm system 75 Ohm system Note: As measured in ANADIGICS test fixture Table 6: Logic Interface Specifications TA=25°C; VDD, VATTN = +5.0 VDC PAR AMETER Attenuator C ontrol Logi c VIN,LOW VIN,HIGH MIN TYP MAX U N IT 0 2.8 - 0.5 5.5 V - 5K - Ohms C OMMEN TS (1) Attenuator C ontrol Impedance Bypasses atten. stage Enables atten. stage Note: (1) Specification applies when 470 Ohm resistor is connected from pin 2 to ground (see test circuit in Figure 4). Table 7: Attenuator Logic ATTEN U ATION (dB ) 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 2 dB Logi c Input (pi n 16) L H L H L H L H L H L H L H L H 4 dB Logi c Input (pi n 15) L L H H L L H H L L H H L L H H 8 dB Logi c Input (pi n 14) L L L L H H H H L L L L H H H H 16 dB Logi c Input (pi n 13) L L L L L L L L H H H H H H H H Note: L = logic low, H = logic high 6 Data Sheet - Rev 2.0 07/2001 +5 V Note: The 470 Ohm resistor from pin 2 to ground is installed for 3V attenuator control logic levels. For 5V logic, the 470 Ohm resistor is removed. 1uF 470 Ohms (see note) 0.01uF 3.3K Ohms 10uH 0.1uF Figure 4: Test Circuit Data Sheet - Rev 2.0 07/2001 0.1uF 1uF 1.8K Ohms 620 Ohms 20 Ohms 0.01uF 1pF 1uF RF Input (75 Ohms) 0.1uF 0.1uF 3.9 Ohms 1uF 0.01uF 1 N/C 2 Bypass 3 ATTIN 4 RFOUT1 5 VREF1 6 N/C 28 N/C 27 ATTOUT 26 ISET2 25 RFIN2 24 ATTACG1 ATTACG2 23 7 ATTACG1 ATTACG2 22 8 ATTACG1 ATTACG2 21 9 ATTACG1 ATTACG2 20 10 RFIN VREF2 19 5K Ohms 0.1uF 0.01uF 0.1uF 620 Ohms 11 ISET1 RFOUT 18 12 VATT GND 17 13 16 dB 2 dB 16 14 8 dB 4 dB 15 1uF 1uF 1.8K Ohms 0.1uF 10uH ARA05050 +5 V RF Output (75 Ohms) 20 Ohms 3.3K Ohms 0.01uF 2 dB 4 dB 8 dB 16 dB 5K Ohms +5 V 1uF ARA05050 7 ARA05050 PERFORMANCE DATA 8 Figure 5: S21 (0 - 16 dB Attenuation) Figure 6: S21 (16 - 30 dB Attenuation) Figure 7: S11 - Log Scale Figure 8: S22 - Log Scale Figure 9: S11 - Smith Chart Figure 10: S22 - Smith Chart Data Sheet - Rev 2.0 07/2001 ARA05050 Figure 11: Attenuator Switching Speed - 16 dB Step Figure 12: Harmonic Performance Data Sheet - Rev 2.0 07/2001 9 ARA05050 APPLICATION INFORMATION Printed Circuit Board Layout Considerations The ARA05050 is a high-performance RF device. Special consideration must be given to certain features of the the printed circuit board layout, as they can affect the RF performance of the IC. Refer to the ANADIGICS application note CATV Reverse Amp w/ Step Attenuator for more details. Thermal Layout Considerations The device package for the ARA05050 features a heat slug on the bottom of the package body. Use of the heat slug is an integral part of the device design. Soldering it to the ground plane of the PC board will ensure the lowest possible thermal resistance for the device, and will result in the longest MTF (mean time to failure.) Amplifier Enable / Disable The ARA05050 includes two amplification stages that each can be shut down through external control pins VREF1 and VREF2 (pins 5 and 19, respectively.) By applying a typical bias of 1.75 Volts to these pins, the amplifiers are enabled. In order to fully disable an amplifier, its control pin requires a negative bias of -1.5 to -2.0 Volts. A PC board layout that optimizes the benefits of the heat slug is shown in Figure 13. The via holes located under the body of the device must be plated through to a ground plane layer of metal, in order to provide sufficient thermal conductivity. The recommended solder mask outline is shown in Figure 14. Amplifier Bias Current The ISET pins (11 and 25) set the bias current for the amplification stages. Grounding these pins results in the maximum possible current. By placing a resistor from the pin to ground, the current can be reduced. The recommended bias conditions use the configuration shown in the test circuit schematic in Figure 4. ESD Sensitivity Electrostatic discharges can cause permanent damage to this device. Electrostatic charges accumulate on test equipment and the human body, and can discharge without detection. Proper precautions and handling are strongly recommended. Refer to the ANADIGICS application note on ESD precautions. Figure 13: PC Board Layout 10 Data Sheet - Rev 2.0 07/2001 ARA05050 Figure 14: Solder Mask Outline Data Sheet - Rev 2.0 07/2001 11 ARA05050 PACKAGE OUTLINE Figure 15: S12 Package Outline - 28 Pin SSOP with Heat Slug 12 Data Sheet - Rev 2.0 07/2001 ARA05050 COMPONENT PACKAGING Volume quantities of the ARA05050 are supplied on tape and reel. Each reel holds 3,500 pieces. Smaller quantities are available in plastic tubes of 50 pieces. Figure 16: Reel Dimensions DIRECTION OF FEED Figure 17: Tape Dimensions Data Sheet - Rev 2.0 07/2001 13 ARA05050 NOTES 14 Data Sheet - Rev 2.0 07/2001 ARA05050 NOTES Data Sheet - Rev 2.0 07/2001 15 ARA05050 ORDERING INFORMATION OR D ER N U MB ER TEMPER ATU R E R AN GE PAC K AGE D ESC R IPTION ARA05050S12C TR -40 to 85 0C 28 Pi n SSOP wi th Heat Slug 3,500 pi ece tape and reel ARA05050S12C -40 to 85 0C 28 Pi n SSOP wi th Heat Slug Plasti c tubes (50 pi eces per tube) C OMPON EN T PAC K AGIN G ANADIGICS, Inc. 141 Mount Bethel Road Warren, New Jersey 07059, U.S.A. Tel: +1 (908) 668-5000 Fax: +1 (908) 668-5132 URL: http://www.anadigics.com E-mail: [email protected] IMPORTANT NOTICE ANADIGICS, Inc. reserves the right to make changes to its products or to discontinue any product at any time without notice. The product specifications contained in Advanced Product Information sheets and Preliminary Data Sheets are subject to change prior to a products formal introduction. Information in Data Sheets have been carefully checked and are assumed to be reliable; however, ANADIGICS assumes no responsibilities for inaccuracies. ANADIGICS strongly urges customers to verify that the information they are using is current before placing orders. WARNING ANADIGICS products are not intended for use in life support appliances, devices or systems. Use of an ANADIGICS product in any such application without written consent is prohibited. 16 Data Sheet - Rev 2.0 07/2001