ATTENUATORS - DIGITAL - CHIP
1
1 - 1
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
HMC941
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
v00.0910
Electrical Specications, TA = +25° C, With Vdd = +5V, Vss = -5V & VCTL = 0/ +5V
The HMC941 is ideal for:
• Fiber Optics & Broadband Telecom
• Microwave Radio & VSAT
• Military Radios, Radar & ECM
• Space Applications
0.5 dB LSB Steps to 15.5 dB
Single Positive Control Line Per Bit
±0.5 dB Typical Bit Error
High Input IP3: +45 dBm
Die Size: 2.29 x 0.95 x 0.1 mm
The HMC941 die is a broadband 5-bit GaAs IC digi-
tal attenuator MMIC chip. Covering 0.1 to 30 GHz, the
insertion loss is less than 4 dB typical. The attenuator
bit values are 0.5 (LSB), 1, 2, 4, 8, for a total attenu-
ation of 15.5 dB. Attenuation accuracy is excellent
at less than ± 0.5 dB typical step error with an IIP3 of
+45 dBm. Five control voltage inputs, toggled between
+5V and 0V, are used to select each attenuation state.
Parameter Frequency (GHz) Min. Typ. Max. Units
Insertion Loss 0.1 - 18.0 GHz
18.0 - 30.0 GHz
2.5
4.0
3.5
4.8
dB
dB
Attenuation Range 0.1 - 30.0 GHz 15.5 dB
Return Loss (RF1 & RF2, All Atten. States) 0.1 - 30.0 GHz 15 dB
Attenuation Accuracy: (Referenced to Insertion Loss)
0.5 - 7.5 dB States
8 - 15.5 dB States
0.1 - 30.0 GHz
0.1 - 30.0 GHz
± 0.3 + 4% of Atten. Setting Max
± 0.3 + 5% of Atten. Setting Max
dB
dB
Input Power for 0.1 dB Compression 0.1 - 0.5 GHz
0.5 - 30.0 GHz
22
27
dBm
dBm
Input Third Order Intercept Point
(Two-Tone Input Power= 0 dBm Each Tone)
0.1 - 0.5 GHz
0.5 - 30.0 GHz
42
45
dBm
dBm
Switching Characteristics
tRISE, tFALL (10/90% RF)
tON/tOFF (50% CTL to 10/90% RF)
0.1 - 30.0 GHz
60
90
ns
ns
Idd 0.1 - 30.0 GHz 3 5 7 mA
Iss 0.1 - 30.0 GHz -4 -6 -8 mA
General Description
Features
Functional Diagram
Typical Applications
ATTENUATORS - DIGITAL - CHIP
1
1 - 2
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
Input Return Loss
(Only Major States are Shown)
Output Return Loss
(Only Major States are Shown)
Insertion Loss vs. Temperature
Normalized Attenuation
(Only Major States are Shown)
Bit Error vs. Frequency
(Only Major States are Shown)
Bit Error vs. Attenuation State
-6
-5
-4
-3
-2
-1
0
0 5 10 15 20 25 30 35 40
+25 C
+85 C
-55 C
INSERTION LOSS (dB)
FREQUENCY (GHz)
-50
-40
-30
-20
-10
0
0 5 10 15 20 25 30 35 40
RETURN LOSS (dB)
FREQUENCY (GHz)
-50
-40
-30
-20
-10
0
0 5 10 15 20 25 30 35 40
RETURN LOSS (dB)
FREQUENCY (GHz)
-20
-15
-10
-5
0
0 5 10 15 20 25 30 35 40
NORMALIZED ATTENUATION (dB)
FREQUENCY (GHz)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0 4 8 12 16
10 GHz
20 GHz
30 GHz
BIT ERROR (dB)
ATTENUATION STATE (dB)
-1.5
-1
-0.5
0
0.5
1
1.5
0 5 10 15 20 25 30 35 40
BIT ERROR (dB)
FREQUENCY (GHz)
15.5 dB
HMC941
v00.0910
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
ATTENUATORS - DIGITAL - CHIP
1
1 - 3
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
Truth Table
Control Voltage Input Attenuation
State
RF1 - RF2
P4
8 dB
P3
4 dB
P2
2 dB
P1
1 dB
P0
0.5 dB
High High High High High Reference I.L.
High High High High Low 0.5 dB
High High High Low High 1 dB
High High Low High High 2 dB
High Low High High High 4 dB
Low High High High High 8 dB
Low Low Low Low Low 15.5 dB
Any Combination of the above states will provide an attenuation
approximately equal to the sum of the bits selected.
20
30
40
50
60
0 5 10 15 20 25 30 35 40
IP3 (dBm)
FREQUENCY (GHz)
15.5 dB8 dB
HMC941
v00.0910
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
Relative Phase vs. Frequency
(Only Major States are Shown) Step Attenuation vs. Attenuation State
Input IP3 vs. Temperature
(Minimum Attenuation State)
Input IP3 Over Major Attenuation States
Input Power for 0.1 dB Compression
-10
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40
RELATIVE PHASE (deg)
FREQUENCY (GHz)
15.5 dB
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0 4 8 12 16
10 GHz
20 GHz
30 GHz
STEP ATTENUATION (dB)
ATTENUATION STATE (dB)
20
30
40
50
60
0.1 1 10 100
+25 C
+85 C
-40 C
IP3 (dBm)
FREQUENCY (GHz)
6
10
14
18
22
26
30
0.01 0.1 1 10 100
P0.1dB (dBm)
FREQUENCY (GHz)
ATTENUATORS - DIGITAL - CHIP
1
1 - 4
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
Control Voltage
Bias Voltages & Currents
Absolute Maximum Ratings
State Bias Condition
Low 0 to 0.8V @ 1 µA
High 2 to 5V @ 1 µA
Vdd +5V @ 5 mA
Vss -5V @ 6 mA
RF Input Power (0.5 to 30 GHz) +27 dBm
Control Voltage (P0 to P4) Vdd + 0.5V
Vdd +7 Vdc
Vss -7 Vdc
Channel Temperature 150 °C
Thermal Resistance
(channel to die bottom) 146 °C/W
Storage Temperature -65 to + 150 °C
Operating Temperature -55 to +85 °C
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
HMC941
v00.0910
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
Die Packaging Information [1]
Standard Alternate
WP-9 (Waffle Pack) [2]
[1] Refer to the “Packaging Information” section for die
packaging dimensions.
[2] For alternate packaging information contact Hittite
Microwave Corporation.
Outline Drawing
1. ALL DIMENSIONS ARE IN INCHES (MILLIMETERS).
2. TYPICAL BOND PAD IS .004” SQUARE.
3. TYPICAL BOND PAD SPACING IS .006”
CENTER TO CENTER EXCEPT AS NOTED.
4. BACKSIDE METALIZATION: GOLD
5. BACKSIDE METAL IS GROUND
6. BOND PAD METALIZATION: GOLD
ATTENUATORS - DIGITAL - CHIP
1
1 - 5
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
Assembly Diagram
HMC941
v00.0910
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
Pad Number Function Description Interface Schematic
GND Die bottom must be connected to RF ground.
1, 9 RF1, RF2 This pad is DC coupled and matched to 50 Ohm. Blocking
capacitors are required if RF line potential is not equal to 0V.
2 Vss Negative Bias -5V
3 - 7 P0 - P4 See truth table and control voltage table.
8 Vdd Positive Bias +5V
Pad Descriptions
ATTENUATORS - DIGITAL - CHIP
1
1 - 6
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
HMC941
v00.0910
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
Mounting & Bonding Techniques for Millimeterwave GaAs MMICs
The die should be attached directly to the ground plane eutectically or with
conductive epoxy (see HMC general Handling, Mounting, Bonding Note).
50 Ohm Microstrip transmission lines on 0.127mm (5 mil) thick alumina
thin lm substrates are recommended for bringing RF to and from the chip
(Figure 1). If 0.254mm (10 mil) thick alumina thin lm substrates must be
used, the die should be raised 0.150mm (6 mils) so that the surface of
the die is coplanar with the surface of the substrate. One way to accom-
plish this is to attach the 0.102mm (4 mil) thick die to a 0.150mm (6 mil)
thick molybdenum heat spreader (moly-tab) which is then attached to the
ground plane (Figure 2).
Microstrip substrates should brought as close to the die as possible in
order to minimize bond wire length. Typical die-to-substrate spacing is
0.076mm to 0.152 mm (3 to 6 mils).
Handling Precautions
Follow these precautions to avoid permanent damage.
Storage: All bare die are placed in either Waffle or Gel based ESD protec-
tive containers, and then sealed in an ESD protective bag for shipment.
Once the sealed ESD protective bag has been opened, all die should be
stored in a dry nitrogen environment.
Cleanliness: Handle the chips in a clean environment. DO NOT attempt
to clean the chip using liquid cleaning systems.
Static Sensitivity: Follow ESD precautions to protect against ESD
strikes.
Transients: Suppress instrument and bias supply transients while bias is
applied. Use shielded signal and bias cables to minimize inductive pick-
up.
General Handling: Handle the chip along the edges with a vacuum collet
or with a sharp pair of bent tweezers. The surface of the chip has fragile air bridges and should not be touched with
vacuum collet, tweezers, or ngers.
Mounting
The chip is back-metallized and can be die mounted with AuSn eutectic preforms or with electrically conductive epoxy.
The mounting surface should be clean and at.
Eutectic Die Attach: A 80/20 gold tin preform is recommended with a work surface temperature of 255 °C and a tool
temperature of 265 °C. When hot 90/10 nitrogen/hydrogen gas is applied, tool tip temperature should be 290 °C. DO
NOT expose the chip to a temperature greater than 320 °C for more than 20 seconds. No more than 3 seconds of
scrubbing should be required for attachment.
Epoxy Die Attach: Apply a minimum amount of epoxy to the mounting surface so that a thin epoxy llet is observed
around the perimeter of the chip once it is placed into position. Cure epoxy per the manufacturer’s schedule.
Wire Bonding
Ball or wedge bond with 0.025mm (1 mil) diameter pure gold wire. Thermosonic wirebonding with a nominal stage
temperature of 150 °C and a ball bonding force of 40 to 50 grams or wedge bonding force of 18 to 22 grams is recom-
mended. Use the minimum level of ultrasonic energy to achieve reliable wirebonds. Wirebonds should be started on
the chip and terminated on the package or substrate. All bonds should be as short as possible <0.31mm (12 mils).
0.102mm (0.004”) Thick GaAs MMIC
Wire Bond
RF Ground Plane
0.127mm (0.005”) Thick Alumina
Thin Film Substrate
0.076mm
(0.003”)
Figure 1.
0.102mm (0.004”) Thick GaAs MMIC
Wire Bond
RF Ground Plane
0.254mm (0.010”) Thick Alumina
Thin Film Substrate
0.076mm
(0.003”)
Figure 2.
0.150mm (0.005”) Thick
Moly Tab