ARA1400

ARA1400 Reverse Amplifier with Step Attenuator Data Sheet - Rev 2.1 FEATURES • • • • • • • Low cost integrated monolothic GaAs amplifier with step attenuator Attenuation Range: 0-56 dB, adjustable in 4 dB increments via a 4 wire parallel control Meets DOCSIS distortion requirements at +60 dBmV output signal level Low distortion and low noise Frequency range: 5-100 MHz 5 Volt operation 0 to +85 °C temperature range APPLICATIONS • • • • • MCNS/DOCSIS Compliant Cable Modems CATV Interactive Set-Top Box Telephony over Cable Systems OpenCable Set-Top Box Residential Gateway S12 Package 28 Pin SSOP with Heat Slug PRODUCT DESCRIPTION The ARA1400 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. The device is capable of meeting the MCNS/DOCSIS requirements for 4 Attenuation Control harmonic performance at a +60dBmV output level while requiring only a single polarity +5V supply. Both the input and the output are single-ended and matched to 75 Ohms, and a precision attenuator provides up to 56 dB of attenuation in 4 dB increments. The device is offered in a 28-pin SSOP package featuring a heat slug on the bottom of the package. ARA1400 LPF Balun Upstream QPSK/16QAM Modulator Clock Data RAM ROM 5-42 MHz Transmit Enable/Disable MAC Clock 44 MHz Data Microcontroller with Ethernet MAC Diplexer 54-860 MHz DoubleConversion Tuner SAW Filter QAM Receiver with FEC 10Base-T Transceiver RJ45 Connector Figure 1: Cable Modem or Set Top Box Application Diagram 03/2004 ARA1400 RFOUT1 ATT IN ATT OUT RFIN2 56 dB 4 dB step digital attenuator section RFIN AMP AMP RFOUT ISET1 32 dB 16 dB 8 dB 4 dB ISET2 Tx Figure 2: Functional Block Diagram 1 2 3 4 5 6 7 8 9 10 11 12 13 14 GND N/C ATT IN RFOUT1 VREF1 ATT ACG1 ATT ACG1 ATT ACG1 ATT ACG1 RFIN ISET1 VATT 32 dB 16 dB ATTOUT ISET2 RFIN2 Tx ATTACG3 ATTACG2 ATTACG2 ATTACG2 ATTACG2 RFOUT VREF2 VA2 4 dB 8 dB 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Figure 3: Pinout 2 Data Sheet - Rev 2.1 03/2004 ARA1400 Table 1: Pin Description PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NAME GND N/C ATTIN RFOUT1 VREF1 ATTACG1 ATTACG1 ATTACG1 ATTACG1 RFIN ISET1 VATT 32 dB 16 dB DESCRIPTION Ground No Connection (1) PIN 15 16 17 18 19 (3) NAME 8 dB 4 dB V A2 VREF2 RFOUT ATTACG2 ATTACG2 ATTACG2 ATTACG2 ATTACG3 Tx RFIN2 ISET2 ATTOUT DESCRIPTION 82 dB Attenution Control Bit 4 dB Attenution Control Bit Amplifier A2 Supply Reference Voltage for Amplifier A2 RF Output from Switch (2) Attenuator AC Ground 2 Attenuator AC Ground 2 Attenuator AC Ground 2 Attenuator AC Ground 2 Attenuator AC Ground 3 Output Switch Control Amplifier A2 Input (4) Amplifier A2 Current Adjust Attenuator Output (2) (3) Attenuator Input (2) Amplifier A1 Output and Supply Reference Voltage for Amplifier A1 Attenuator AC Ground 1 Attenuator AC Ground 1 Attenuator AC Ground 1 Attenuator AC Ground 1 Amplifier A1 Input (4) Amplifier A1 Current Adjust Attenuator Supply 32 dB Attenution Control Bit 16 dB Attenution Control Bit 20 21 22 23 24 25 26 27 28 (3) (3) (3) (3) (3) (3) (3) 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 AC-coupled from the RF path, and should be pulled to ground through a resistor. Data Sheet - Rev 2.1 03/2004 3 ARA1400 ELECTRICAL CHARACTERISTICS Table 2: Absolute Minimum and Maximum Ratings PARAMETER Analog Supply: VSUP (pins 4, 12, 17) Amplifier Reference Voltages (pins 5, 18) RF Power at Amplifier Inputs (pins 10, 26) MIN 0 -2.5 0 0 -55 - MAX 9 VSUP 2 +60 6 6 +200 260 5 UNIT VD C VD C dBmV V V °C °C S ec Attenuator Controls (pins 13, 14, 15, 16) Output Switch Control (pin 25) Storage Temperature Soldering Temperature Soldering Time 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, 19, and 28 should be AC-coupled. No external DC bias should be applied. 2. Pins 11 and 27 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, 23 and 24 should be AC-grounded. No external DC bias should be applied. 4. Pins 10 and 26 should be AC-coupled from the RF path, and should be pulled to ground through a resistor. Table 3: Operating Ranges PARAMETER Amplifier Supply: VDD (pins 4, 17) Attenuator Supply: VATTN (pin 12) Attenuator Controls (pins 13, 14, 15, 16) Amplifier Reference Voltages (pins 5, 18) Output Switch Control (pin 25) Case Temperature MIN 4.5 VDD-0.5 0 0 0 TYP 5 5 1.75 25 MAX 7 7 5.5 5.5 85 UNIT VD C VD C V VD C V °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 2.1 03/2004 ARA1400 Table 4: DC Electrical Specifications (TA = 25 °C; VDD,VATTN = +5.0 VDC) PARAMETER Amplifier A1 Current (pin 4) Amplifier A2 Current (pin 17) Attenuator Current (pin 12) Total Power Consumption MIN TYP 74 108 12 0.97 MAX 95 130 20 1.23 UNIT mA mA mA W COMMENTS Table 5: AC Electrical Specifications (TA = 25 °C; VDD, VATTN = +5.0 VDC; Tx = 0 V (switch closed), Tx = +5 V (switch open)) PARAMETER Gain (10 MHz) Gain Flatness Gain Variation over Temperature Attenuation Steps 4 dB 8 dB 16 dB 32 dB Switch Isolation at 45 MHz Harmonics (fo = 10MHz) 2fo 3fo 3rd Order Output Intercept 1 dB Gain Compression Point Noise Figure Output Noise Power Active / No Signal / Min. Atten. Set. Active / No Signal / Max. Atten. Set. Input Impedance Note: As measured in ANADIGICS test fixture. MIN 30 3.6 7.7 15.3 31.0 - TYP 32 0.75 -0.006 3.9 8.0 15.7 31.5 35 MAX 33 4.2 8.3 16.1 32.0 30 UNIT dB dB dB/°C COMMENTS 0 dB attenuation setting 5 to 100 MHz dB Monotonic dB Difference in output signal level between active and standby fo power = +60 dBmV into 75 Ohms 78 - -57 -64 70 1.7 75 -52 -56 2.5 -37.6 -54.6 - dB c dBmV dBmV dB dBmV Ohms Any 160 kHz bandwidth from 5 to 42 MHz Data Sheet - Rev 2.1 03/2004 5 ARA1400 continued: AC Electrical Specifications (TA = 25 °C; VDD, VATTN = +5.0 VDC; Tx = 0 V (switch closed), Tx = +5 V (switch open)) PARAMETER Input Return Loss (75 Ohm characteristic impedance) Output Impedance Output Return Loss (75 Ohm characteristic impedance) Output Voltage Transient switch closed / switch open Note: As measured in ANADIGICS test fixture. MIN - TYP -20 -20 -12 -17 -15 4 MAX -15 -15 -10 -12 -10 7 UNIT dB Ohms dB mVp-p COMMENTS Switch closed Switch open Switch closed Switch open Table 6: Logic Interface Specifications (TA = 25 °C; VDD, VATTN = +5.0 VDC) PARAMETER Attenuator Control Logic VIN,LOW VIN,HIGH Attenuator Control Impedance Output Switch Control Logic VIN,LOW VIN,HIGH Output Switch Control Impedance MIN 0 2.7 0 2.8 TYP 5K 10 K MAX 0.5 5.5 1 5.5 UNIT COMMENTS Bypasses atten. stage Enables atten. stage V Ohms V Ohms Switch closed Swicth open Table 7: Attenuator Logic ATTENUATION (dB) 4 dB Logic Input (pin 16) 8 dB Logic Input (pin 15) 16 dB Logic Input (pin 14) 32 dB Logic Input (pin 13) 0 L L L L 4 H L L L 8 L H L L 12 H H L L 16 L L H L 20 H L H L 24 L H H L 28 H H H L 32 L L L H 36 H L L H 40 L H L H 44 H H L H 48 L L H H 52 H L H H 56 L H H H 60 H H H H Notes: “L” = logic low, “H” = logic high 6 Data Sheet - Rev 2.1 03/2004 +5 V 1uF 5K Ohms 0.1uF 1 GND ATTOUT ISET2 RFIN2 Tx ATTACG3 24 ATTACG2 ATTACG2 ATTACG2 ATTACG2 RFOUT VREF2 VA2 4 dB 8 dB ARA1400 21 20 19 18 17 16 15 22 23 25 26 27 28 3.3K Ohms N/C ATTIN RFOUT1 VREF1 ATTACG1 ATTACG1 ATTACG1 ATTACG1 RFIN ISET1 VATT 32 dB 16 dB 0.1uF 3 10uH 2 0.1uF 5K Ohms 10K Ohms 1uF 0.1uF 620 Ohms 1uF 1.8K Ohms 20 Ohms 10uH 1uF 3.3K Ohms 0.1uF RF Output (75 Ohms) 0.1uF 1uF 5 0.1uF 4 1.8K Ohms 20 Ohms 6 7 8 9 10 11 12 Output Switch Control (0 / +5 V) 620 Ohms 1uF 0.1uF 1pF 0.1uF RF Input (75 Ohms) 8 dB 4 dB 32 dB 16 dB Figure 4: Test Circuit 1uF 14 Data Sheet - Rev 2.1 03/2004 1uF 13 0.1uF 3.9 Ohms +5 V 5K Ohms 0.1uF 1uF +5 V Note: Output Switch Closed: Output Switch Control = 0 V Output Switch Open: Output Switch Control = +5 V ARA1400 7 ARA1400 APPLICATION INFORMATION Amplifier Enable / Disable The ARA1400 includes two amplification stages that each can be shut down through external control pins VREF1 and VREF2 (pins 5 and 18, 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. Output Switch Control A switch located at the output of Amplifier A2 in the ARA1400 provides isolation without having to disable the amplifiers. The switch is controled by the Tx logic input (pin 25). Amplifier Bias Current The ISET pins (11 and 27) 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. Thermal Layout Considerations The device package for the ARA1400 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.) A PC board layout that optimizes the benefits of the heat slug is shown in Figure 5. 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 6. ESD Sensitivity Electrostatic discharges can cause permanent damage to these devices. 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. 0.025 BSC 0.089 0.014 TYP BODY OUTLINE (NOMINAL) 0.025 MIN. 0.163 0.099 0.197 0.070 0.150 0.060 TYP. (12X)0.020 TO 0.060 DIA.P PLATED THRU HOLES. 0.400 DIMENSIONS IN INCHES Figure 5: PC Board Layout 8 Data Sheet - Rev 2.1 03/2004 ARA1400 0.016 TYP. 0.091 0.025 TYP. 0.163 0.0535 0.242 0.085 0.098 0.025 BSC 0.145 DIMENSIONS IN INCHES Figure 6: Solder Mask Outline Data Sheet - Rev 2.1 03/2004 9 ARA1400 PACKAGE OUTLINE Figure 7: S12 Package Outline - 28 Pin SSOP with Heat Slug 10 Data Sheet - Rev 2.1 03/2004 ARA1400 COMPONENT PACKAGING Volume quantities of the ARA1400 are supplied on tape and reel. Each reel holds 3,500 pieces. Smaller quantities are available in plastic tubes of 50 pieces. Figure 8: Reel Dimensions Figure 9: Tape Dimensions Data Sheet - Rev 2.1 03/2004 11 ARA1400 ORDERING INFORMATION ORDER NUMBER ARA1400S12CTR ARA1400S12C TEMPERATURE RANGE 0 to 85 °C 0 to 85 °C PACKAGE DESCRIPTION 28 Pin SSOP with Heat Slug 28 Pin SSOP with Heat Slug COMPONENT PACKAGING 3,500 piece tape and reel Plastic tubes (50 pieces per tube) 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: Mktg@anadigics.com 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 product’s 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. 12 Data Sheet - Rev 2.1 03/2004