ARA1400S12

A FEATURES · · · · · · Low cost integrated monolithic GaAs amplifier and step attenuator with output disconnect switch. Meets DOCSIS distortion requirements at +60 dBmV Frequency range: 5 – 100 MHz Attenuation Range: 0 – 56 dB, variable in 4 dB steps 5 Volt operation Low distortion & Low noise figure APPLICATIONS · · · MCNS/DOCSIS Compliant Cable Modems CATV Interactive Set-Top Box Telephony over Cable Systems ARA1400S12 CATV Reverse Amplifier with Step Attenuator Advanced Product Information Rev. 2 28 1 S12 28 PIN SSOP PACKAGE DESCRIPTION The ARA1400S12 is a GaAs IC designed to perform 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. It is capable of meeting the MCNS/DOCSIS harmonic distortion specifications while only requiring a single polarity +5V supply. This part is a single ended design that does not require an output ABSOLUTE MAXIMUM RATINGS balun to achieve –52 dBc 2nd harmonic performance at +60 PARAMETER PARAMETER dBmV output levels. Both the V DD (P INS 4,12,17) 9 VD C input and output are matched to 75 ohms. The precision V RFIN (P INS 10, 26) 0 to -3 VD C attenuator provides up to 56 dB of attenuation in 4 dB ATTIN (3) ATTOUT (28)V 5 VD C increments. The ARA1400S12 V ISET (P INS 11, 27) 2 VD C is supplied in a 28-pin SSOP package featuring a thermal heat RF Input Voltage (P INS 10, 26)* + 60 dB mV slug on the bottom of package. Storage T mperature e - 55 to +200 °C Soldering this heat slug to the ground plane of the PC board S olderi ng T mperature e 260 °C ensures the lowest possible S olderi ng Ti me 5 S ec thermal resistance for the device resulting in a long MTF. Operati ng C ase T mperature e 0 to + 85 °C ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 ELECTRICAL CHARACTERISTICS (TYPICAL) (VDD=5 VDC, TC=25 °C) PA RA ME TE R Gai n 1 MIN 30 1 TYP 32 0.75 -0.006 3.9 8.0 15.7 31.5 -57 -64 70 MA X 33 4.2 8.3 16.1 32.0 -52 -56 2.5 -24.6 -41.6 30 -15 -15 -10 1 VDD 7 -2 95 130 20 1.23 0.5 6.5 - UNIT dB dB dB /°c C OMME NTS A t 0dB attenuati on setti ng 5 to 100 MHz Gai n Flatness 3.6 7.7 15.3 31.0 10 MHz 10 MHz 78 Gai n Vari ati on Over T mp e A ttenuati on Steps 1 4 dB 8 dB 16 dB 32 dB 2 dB 2nd Harmoni c D i storti on Level 3 rd dB c dB c dB mV dB mV dB dB mV at +60 dB mV at +60 dB mV Harmoni c D i storti on Level 2 3rd Order Output Intercept P oi nt 1 dB Gai n C ompressi on P oi nt Noi se Fi gure Ouput Noi se P ower A cti ve/No S i gnal/Mi n A ttn. S etti ng A cti ve/No S i gnal/Max A ttn. S etti ng S wi tch Isolati on at 45 MHz Input Impedance1 Input Return Loss 1 V IL V IH 0 2.8 -1.5 4 1.7 35 75 -20 75 -20 -12 10K 5 5 74 108 12 0.97 5K A ny 3200 K Hz bandwi dth from 5-42 MHz D i fference i n output si gnal level between acti ve and standby dB ohm dB ohm dB dB V V ohm V V V mA mA mA W Volts ohm Output Impedance1 Output Return Loss1 Output Return Loss 1 Tx enabled Tx di sabled (OP E N) (C LOS E D ) Output S wi tch C ontrol Logi c Output S wi tch C ontrol Impedance V D D 1, V D D 2 V D D D i gi tal V S hutdown I DD1 I DD2 I D D D i gi tal P ower C onsumpti on A ttenuator C ontrol Logi c V IL V IH 0 2.7 - A ttn. D i sabled A ttn. E nabled A ttenuator C ontrol Impedance Notes: 1. As measured in ANADIGICS test fixture 2. At +60 dBmV output level into 75 ohm load A 2 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 Tx Enable/Disable Gain Control PA Switch ATTN 4/8/16/32 dB PA LPF Balun Upstream QPSK/ 16-QAM Modulator ARA1400 Reverse Amp Coax Connector Clock Data Microcontroller w/Enet MAC RAM ROM MAC Diplex Filter Clock 45 MHz IF 54-860 MHz Double Conversion Tuner SAW QAM Receiver w/FEC Data 10Base-T Tranceiver RJ45 Connector Figure 1: Cable Modem or Interactive Set-Top Box Block Diagram RFOUT1 ATTIN ATTOUT RFIN2 56 dB 4 dB step digital attenuator section RFIN AMP RFOUT AMP ISET1 32 dB 16 dB 8 dB 4 dB ISET2 Tx Figure 2 A 3 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 TEST CIRCUIT GND 1 2 3 Vdd1 28 27 26 25 24 23 22 21 20 19 18 17 16 15 REVERSE AMP GND GND .1uF GND .1uF 10K 5K 5K 0.1uF Output Switch Control 10uH .01uF 1uF 600 Ω 1pF GND .1uF 20 Ω 1uF 1uF .1uF GND 4 5 6 7 8 9 3.3K 1.8K Shutdown #2 GND GND 1uF GND ARA1400 GND 0.1uF 1uF 620 Ω 5K .1uF GND GND GND RFOUT RFIN .1uF 5K 0.1uF 10 11 12 20 Ω 10uH .1uF 1uF 3.3K .01uF 1uF 1.8K Vdd2 Shutdown #1 0.1uF 5K 1uF 3.9 Ω 1uF GND GND 13 14 F 5V DIGITAL +5V 32 dB 16 dB 8 dB 4 dB SW4 SW3 SW2 SW1 DIP SWITCH LOGIC TABLE Attn (dB ) SW 1 SW 2 SW 3 S W4 4 X O O O 8 O X O O 12 X X O O 16 O O X O 20 X O X O 24 O X X O 28 X X X O 32 O O O X 36 X O O X 40 O X O X 44 X X O X 48 O O X X 52 X O X X 56 O X X X 60 X X X X O = Open (0 Vdc) X = Closed (+5 Vdc) A 4 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 PACKAGE DIAGRAM A 5 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 PIN DESCRIPTION P IN 1 2 3 4 5 6,7,8,9 FU N C TION D i g GND NC ATTIN RFOUT1+V DD1 V REF1 A C _GND 1 A ttenuator Input RF Output and +5v S upply for 1st A mpli fi er Stage Reference voltage for 1st A mpli fi er A C Ground for 32 dB attenuator bi t. These pi ns must be externally ac decoupled RF Input to 1st A mpli fi er Stage & S hutdown pi n for 1st A mpli fi er Resi stor S et C urrent for 1st A mpli fi er 5 volts di gi tal supply voltage 32 dB A ttenuator C ontrol P arallel data i nput 16 dB A ttenuator C ontrol P arallel data i nput 8 dB A ttenuator C ontrol P arallel data i nput 4 dB A ttenuator C ontrol P arallel data i nput +5V S upply for 2nd A mpli fi er Stage Reference voltage for 2nd A mpli fi er RF Output From S wi tch A C Ground for 4,8, 16 dB attenuator bi ts. These pi ns must be externally ac decoupled. A C Ground for output swi tch. These pi ns must be externally ac decoupled. Output S wi tch C ontrol RF Input to 2nd A mpli fi er Stage and S hutdown pi n for 2nd A mpli fi er Resi stor set current for 2nd A mpli fi er (ground for max performance) A ttenuator Output D E S C R IP TION D i gi tal Ground 10 11 12 13 14 15 16 17 18 19 20,21,22,23 RFIN ISET1 5V di gi tal 32 dB 16 dB 8 dB 4 dB VDD2 RREF2 RFOUT A C _GND 2 24 25 26 A C _GND 3 Tx RFIN2 ISET2 ATTOUT 27 28 A 6 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 NOTES A 7 ARA1400S12 CATV REVERSE AMPLIFIER WITH STEP ATTENUATOR Advanced Product Information Rev. 2 A ANADIGICS, Inc. 35 Technology Drive Warren, New Jersey 07059 Tel: (908) 668-5000 Fax: (908) 668-5132 http://www.anadigics.com Mktg@anadigics.com IMPORTANT NOTICE ANADIGICS, Inc. reserves the right to make changes to its products or discontinue any product at any time without notice. The Advanced Product data sheets and product specifications contained in this data sheet are subject to change prior to a products formal introduction. The information in this data sheet has been carefully checked and is assumed to be reliable. However, ANADIGICS assumes no responsibility 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. A 8