04/2012
FEATURES
• LowCostIntegratedMonolothicGaAsAmplier
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 toNoise Ratio at All Gain Levels
• Frequency Range: 5-100 MHz
• 5 Volt Operation
• RoHS-Compliant Package Option
APPLICATIONS
• MCNS/DOCSIS Compliant Cable Modems
• CATV Interactive Set-Top Box
• OpenCable Set-Top Box
• Fiber Nodes
• Cable Modem Termination Systems (CMTS)
PRODUCT DESCRIPTION
The ARA05050 is a GaAs IC designed to provide the
reverse path amplication 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
amplierstage,andfollowedbyanultra-linearoutput
driver amplier. This device is capable of meeting
the MCNS/DOCSIS requirements for harmonic
Figure 1. Cable Modem or Set Top Box Application Diagram
S12 Package
28 Pin SSOP with Heat Slug
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 that features a heat
slug on the bottom of the package, and is available in
a RoHS-compliant option.
LPF
Diplexer
ARA05050
SAW
Filter
Double-
Conversion
Tuner
MAC
Upstream
QPSK/16QAM
Modulator
QAM Receiver
with FEC
Balun
Transmit Enable/Disable
Attenuation Control
Microcontroller
with Ethernet
MAC
RAM ROM
10Base-T
Transceiver
RJ45
Connecto
r
Clock
Clock
Data
Data
54-860 MHz
44 MHz
5-42 MHz
4
LPF
Switch
ARA05050
ReverseAmplierwithStepAttenuator
Data Sheet - Rev 2.7
2Data Sheet - Rev 2.7
04/2012
ARA05050
Figure 2: Functional Block Diagram
Figure 3: Pinout
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
N/C
ISET1
N/C
ATT
ACG1
ATTOUT
VREF1
RFOUT1
ATTIN
16 dB
VATT
8 dB
RFIN
N/C
VREF2
ISET2
GND
Bypass
RFOUT2
ATTACG2
RFIN2
ATTACG1
ATTACG1
ATTACG1 ATTACG2
ATTACG2
ATT
ACG2
2 dB
4 dB
RF
IN RF OUT
2
I
SET2
I
SET1
16 dB 2 dB4 dB8 dB
RF IN2
RF OUT1 ATTOUT
ATTIN
A1 A2
30 dB, 2dB step digital attenuator section
3Data Sheet - Rev 2.7
04/2012
ARA05050
Table 1: Pin Description
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.
PIN NAME DESCRIPTION PIN NAME DESCRIPTION
1N/C No Connection
(1)
28 N/C No Connection
(1)
2Bypass Internal Bypass 27 N/C No Connection
(1)
3ATT
IN
Attenuator Input
(2)
26 ATT
OUT
Attenuator Output
(2)
4RF
OUT1
Amplifier A1 Output and Supply 25 I
SET2
Amplifier A2 Current Adjust
(4)
5 V
REF1
Reference Voltage for Amplifier
A1 24 RF
IN2
Amplifier A2 Input
(4)
6ATT
ACG1
Attenuator AC Ground 1
(3)
23 ATT
ACG2
Attenuator AC Ground 2
(3)
7ATT
ACG1
Attenuator AC Ground 1
(3)
22 ATT
ACG2
Attenuator AC Ground 2
(3)
8ATT
ACG1
Attenuator AC Ground 1
(3)
21 ATT
ACG2
Attenuator AC Ground 2
(3)
9ATT
ACG1
Attenuator AC Ground 1
(3)
20 ATT
ACG2
Attenuator AC Ground 2
(3)
10 RF
IN
Amplifier A1 Input
(4)
19 V
REF2
Reference Voltage for Amplifier A2
11 I
SET1
Amplifier A1 Current Adjust
(4)
18 RF
OUT2
Amplifier A2 Output and Supply
12 V
ATT
Attenuator Supply 17 GND Ground
13 16 dB 16 dB Attenution Control Bit 16 2 dB 2 dB Attenuition Control Bit
14 8 dB 8 dB Attenution Control Bit 15 4 dB 4 dB Attenuition Control Bit
4Data Sheet - Rev 2.7
04/2012
ARA05050
ELECTRICAL CHARACTERISTICS
Table 2: Absolute Minimum and Maximum Ratings
Table 3: Operating Ranges
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.
The device may be operated safely over these conditions; however, parametric performance is
guaranteed only over the conditions dened in the electrical specications.
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.
PARAMETER MIN MAX UNIT
Analog Supply: V
SUP
(pins 4, 12, 18) 0 9 VDC
Amplifier Reference Voltages (pins 5, 19) -2.5 V
SUP
2VDC
RF Power at Amplifier Inputs (pins 10, 24)-+60 dBmV
Attenuator Controls (pins 13, 14, 15, 16) 0 6 V
Storage Temperature -55 +200 °C
Soldering Temperature -260 °C
Soldering Time - 5 Sec
PARAMETER MIN TYP MAX UNIT
Amplifier Supply: VDD (pins 4, 18) 4.5 5 7 VDC
Attenuator Supply: VATTN (pin 12) - 5 7 VDC
Attenuator Controls (pins 13, 14, 15, 16) 0 - 5.5 V
Amplifier Reference Voltages (pins 5, 19) -1.75 -VDC
Output Switch Control (pin 25) 0 - 5.5 V
Case Temperature -40 25 85 °C
5Data Sheet - Rev 2.7
04/2012
ARA05050
Notes:
(1) See Figures 5 and 6 for performance at higher frequencies.
All specications as measured in ANADIGICS test xture.
Table 4: DC Electrical Specications
TA=25°C; VDD, VATTn = +5.0 VDC
Table 5: AC Electrical Specications
TA=25°C; VDD, VATTn = +5.0 VDC
PARAMETER MIN TYP MAX UNIT COMMENTS
Amplifier A1 Current (pin 4) -75 95 mA
Amplifier A2 Current (pin 18) -100 130 mA
Attenuator Current (pin 12) - 8 - mA
Total Power Consumption -0.92 1.2 W
Thermal Resistance (
JC
) - 36 -C/W
PARAMETERMINTYPMAXUNITCOMMENTS
Gain (10 MHz) 31 32 33 dB 0 dB attenuation setting
Gain Flatness -0.751.5 dB 5 to 100 MHz
Gain Variation over Te mperature--0.006 -dB/°C
Attenuation Steps
2 dB
4 dB
8 dB
16 dB
1.6
3.8
8.0
16.0
1.85
4.0
8.3
16.6
2.2
4.2
8.5
17.0
dB 5 to 42 MHz (1),
Monotonic
2nd Harmonic Distortion Level
5 MHz
25 MHz
-
-
-60
-63
-55
-55dBc+58 dBmV into 75 Ohms
3rd Harmonic Distortion Level
5 MHz
25 MHz
-
-
-63
-63
-60
-60dBc+58 dBmV into 75 Ohms
3rd Order Output Intercept78- -dBmV
1 dB Gain Compression Point-70 -dBmV
Noise Figure -1.7 2.5dB
6Data Sheet - Rev 2.7
04/2012
ARA05050
Note: As measured in ANADIGICS test xture
continued: AC Electrical Specications
TA=25°C; VDD, VATTn = +5.0 VDC
Table 6: Logic Interface Specications
TA=25°C; VDD, VATTn = +5.0 VDC
Note: “L” = logic low, “H” = logic high
Table 7: Attenuator Logic
Note:
(1) Specication applies when 470 Ohm resistor is connected from pin 2 to ground (see test circuit in Figure 4).
PARAMETER MIN TYP MAX UNIT COMMENTS
Attenuator Control Logic
V
IN
,
LOW
V
IN
,
HIGH
0
2.8
-
-
0.5
5.5 VBypasses atten. stage
Enables atten. stage
Attenuator Control Impedance -5 K -Ohms
ATTENUATION (dB) 0246810 12 14 16 18 20 22 24 26 28 30
2 dB Logic Input (pin 16) L H L H L H L H L H L H L H L H
4 dB Logic Input (pin 15) L L H H L L H H L L H H L L H H
8 dB Logic Input (pin 14) L L L L H H H H L L L L H H H H
16 dB Logic Input (pin 13) L L L L L L L L H H H H H H H H
7Data Sheet - Rev 2.7
04/2012
ARA05050
Figure 4: Test Circuit
227
16
15
1
14
22
24
25
23
21
20
19
18
17
28
26
9
8
7
10
6
11
5
12
4
13
3
GND
ISET1
ATTACG1
RF OUT1
ATTIN
VATTN
16 dB
8 dB 4 dB
ISET2
RF IN2
2 dB
RF IN
N/C
ATTOUT
VREF1
RF OUT2
ATTACG1
ATTACG1
ATTACG1
VREF2
ATTACG2
ATTACG2
ATTACG2
ATTACG2
Bypass
N/C
N/C
(75 Ohms)
0.1uF
RF
Output
(75 Ohms)
3.9 Ohms
8 dB
16 dB
+5 V
RF Input
+5 V
620 Ohms
0.1uF
0.01uF
1uF
0.01uF
ARA05050
10uH
0.01uF
1uF
620 Ohms
2 dB
4 dB
20 Ohms
1uF
0.1uF
0.1uF
0.8pF ±0.1pF
3.3K Ohms
1.8K Ohms
1000pF
5K Ohms
0.01uF
1uF
0.1uF
5K Ohms
+5 V 1uF
0.01uF
10uH
20 Ohms
3.3K Ohms
1.8K Ohms
1uF
0.1uF
470 Ohms
(see note)
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.
0.1 uF
0.01 uF
5K Ohms
5K Ohms
0.01uF
VG2
(Not Used)
VG1
(Not Used)
8Data Sheet - Rev 2.7
04/2012
ARA05050
PERFORMANCE DATA
Figure 5: S21 (0 - 16 dB Attenuation)
Figure 7: S11 - Log Scale Figure 8: S22 - Log Scale
Figure 9: S11 - Smith Chart Figure 10: S22 - Smith Chart
Figure 6: S21 (16 - 30 dB Attenuation)
9Data Sheet - Rev 2.7
04/2012
ARA05050
Figure 12: Harmonic Performance
Figure 11: Attenuator Switching Speed - 16 dB Step
10 Data Sheet - Rev 2.7
04/2012
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.
Amplier Enable / Disable
TheARA05050 includes two amplication 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ampliersareenabled.Inordertofullydisable
anamplier,itscontrolpinrequiresanegativebias
of -1.5 to -2.0 Volts.
Amplier Bias Current
The Iset pins (11 and 25) set the bias current for the
amplication 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
conguration shown in the test circuit schematic in
Figure 4.
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.)
APCboardlayoutthatoptimizesthebenets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
sufcient thermal conductivity. The recommended
solder mask outline is shown in Figure 14.
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
0.025BSC 0.089 0.014TYP
0.025MIN.
0.099
0.197
0.163
0.386REF.
0.152
REF.
BODY OUTLINE
(NOMINAL)
0.070 0.150
0.060TYP.
0.400
(12X)0.020TO 0.060DIA.
P
PLATED THRU HOLES.
11 Data Sheet - Rev 2.7
04/2012
ARA05050
Figure 14: Solder Mask Outline
DIMENSIONSARE IN INCHES
0.145
0.085
0.025TYP.
0.016TYP.
0.025BSC
0.053
0.242
0.163
0.098
0.091
12 Data Sheet - Rev 2.7
04/2012
ARA05050
Figure 15: S12 Package Outline - 28 Pin SSOP with Heat Slug
PACKAGE OUTLINE
13 Data Sheet - Rev 2.7
04/2012
ARA05050
COMPONENT PACKAGING
Figure 17: Tape Dimensions
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
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.
IMPORTANT NOTICE
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
ANADIGICS, Inc. reserves the right to make changes to its products or to discontinue any product at any time without notice.
The product specications 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.
Data Sheet - Rev 2.7
04/2012
14
ARA05050
ORDERING INFORMATION
ORDER NUMBER TEMPERATURE
RANGE
PACKAGE
DESCRIPTION COMPONENT PACKAGING
ARA05050S12CTR -40 to 85 0C28 Pin SSOP
with Heat Slug 3,500 piece tape and reel
ARA05050S12C -40 to 85 0C28 Pin SSOP
with Heat Slug Plastic tubes (50 pieces per tube)
ARA05050RS12P1 -40 to 85 0C
RoHS-compliant
28 Pin SSOP
with Heat Slug
3,500 piece tape and reel