ATTENUATORS - SMT
5
5 - 102
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
HMC346MS8G / 346MS8GE
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz
v07.1008
General Description
Features
Functional Diagram
Wide Bandwidth: DC - 8 GHz
Low Phase Shift vs. Attenuation
32 dB Attenuation Range
Electrical Speci cations, TA = +25° C, 50 ohm system
Typical Applications
This attenuator is ideal for use as a VVA
for DC - 8 GHz applications:
• Point-to-Point Radio
• VSAT Radio
The HMC346MS8G & HMC346MS8GE are absorp-
tive Voltage Variable Attenuators (VVA) in 8 lead sur-
face-mount packages operating from DC - 8 GHz. It
features an on-chip reference attenuator for use with
an external op-amp to provide simple single voltage
attenuation control, 0 to -3V. The device is ideal in
designs where an analog DC control signal must con-
trol RF signal levels over a 30 dB amplitude range.
Applications include AGC circuits and temperature
compensation of multiple gain stages in microwave
point-to-point and VSAT radios.
Parameter Min Typical Max Units
Insertion Loss DC - 8 GHz 1.5 2.5 dB
Attenuation Range DC - 8 GHz 27 32 dB
Return Loss DC - 8 GHz 5 10 dB
Switching Characteristics tRISE, tFALL (10/90% RF)
tON, tOFF (50% CTL to 10/90% RF)
2
8
ns
ns
Input Power for 0.25 dB Compression (0.5 - 8 GHz) Min. Atten.
Atten. >2 dB
+8
-2
dBm
dBm
Input Third Order Intercept (0.5 - 8 GHz)
(Two-tone Input Power = -8 dBm Each Tone)
Min. Atten.
Atten. >2 dB
+25
+10
dBm
dBm
ATTENUATORS - SMT
5
5 - 103
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Relative Attenuation
Relative Attenuation vs.
Control Voltage @ 4 GHz
Insertion Loss vs. Temperature
Return Loss vs. Attenuation
Relative Phase
Relative Attenuation vs.
Control Voltage @ 8 GHz
-4
-3
-2
-1
0
012345678910
T+25C
T -40C
T+85C
INSERTION LOSS (dB)
FREQUENCY (GHz)
-3
-2.5
-2
-1.5
-1
-0.5
0
0 5 10 15 20 25 30
CONTROL VOLTAGE (Vdc)
RELATIVE ATTENUATION (dB)
V2 +85C
V2 +25C
V2 -40C
V1 +85C V1 +25C V1 -40C
-30
-25
-20
-15
-10
-5
0
012345678910
MIN
15 dB
MAX
RETURN LOSS (dB)
FREQUENCY (GHz)
0
20
40
60
80
100
120
140
012345678910
RELATIVE PHASE (DEG)
FREQUENCY (GHz)
5 dB
10 dB
15 dB
20 dB
25 dB 30 dB
max
-3
-2.5
-2
-1.5
-1
-0.5
0
0 5 10 15 20 25 30
CONTROL VOLTAGE (Vdc)
RELATIVE ATTENUATION (dB)
V2 +85C
V2 +25C
V2 -40C
V1 +85C V1 +25C V1 -40C
-40
-30
-20
-10
0
012345678910
ATTENUATION (dB)
FREQUENCY (GHz)
HMC346MS8G / 346MS8GE
v07.1008
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 104
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Input Third Order
Intercept vs Attenuation*
*Two-tone input power = -8 dBm each tone, 1 MHz spacing.
Input Second Order
Intercept vs. Attenuation*
0.25 dB Compression vs. Attenuation 1 dB Compression vs. Attenuation
Second Harmonic vs. Attenuation
20
30
40
50
60
70
80
012345678
0 dB
3 dB
6 dB
10 dB
SECOND HARMONIC (dBc)
FREQUENCY (GHz)
-5
0
5
10
15
20
012345678
0 dB (REF)
5 dB
INPUT P1dB (dBm)
FREQUENCY (GHz)
-5
0
5
10
15
20
012345678
0 dB (REF)
5 dB
INPUT.25dB COMPRESSION (dBm)
FREQUENCY (GHz)
10
20
30
40
50
60
70
012345678
0 dB
3 dB
6 dB
10 dB
SECOND ORDER INTERCEPT POINT (dBm)
FREQUENCY (GHz)
5
10
15
20
25
30
012345678
0 dB
3 dB
6 dB
10 dB
THIRD ORDER INTERCEPT POINT (dBm)
FREQUENCY (GHz)
HMC346MS8G / 346MS8GE
v07.1008
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 105
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Outline Drawing
Absolute Maximum Ratings
RF Input Power +18 dBm
Control Voltage Range +1 to -5 V
Storage Temperature -65 to +150 °C
Operating Temperature -40 to +85 °C
ESD Sensitivity (HBM) Class 1A
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
Part Number Package Body Material Lead Finish MSL Rating Package Marking [3]
HMC346MS8G Low Stress Injection Molded Plastic Sn/Pb Solder MSL1 [1] H346
XXXX
HMC346MS8GE RoHS-compliant Low Stress Injection Molded Plastic 100% matte Sn MSL1 [2] H346
XXXX
[1] Max peak re ow temperature of 235 °C
[2] Max peak re ow temperature of 260 °C
[3] 4-Digit lot number XXXX
Package Information
NOTES:
1. LEADFRAME MATERIAL: COPPER ALLOY
2. DIMENSIONS ARE IN INCHES [MILLIMETERS].
3. DIMENSION DOES NOT INCLUDE MOLDFLASH OF 0.15mm PER SIDE.
4. DIMENSION DOES NOT INCLUDE MOLDFLASH OF 0.25mm PER SIDE.
5. ALL GROUND LEADS AND GROUND PADDLE MUST BE SOLDERED TO
PCB RF GROUND.
HMC346MS8G / 346MS8GE
v07.1008
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 106
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Pin Number Function Description Interface Schematic
1, 8 RF1
RF2
This pin is DC coupled and matched to 50 Ohm. Blocking
capacitors are required if RF line potential is not equal to 0V.
2, 7 GND This pin must be DC grounded.
3, 6 V2, V1 Control Input (Master).
4 I Control Input (Slave).
5N/C Not Connected.
Pin Descriptions
External op-amp control circuit maintains impedance match while attenuation is varied. Input control ranges from 0 Volts
(min. attenuation) to -2.5 Volts (max. attenuation.)
Single-Line Control Driver
HMC346MS8G / 346MS8GE
v07.1008
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 107
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Evaluation PCB
The circuit board used in the  nal application
should be generated with proper RF circuit design
techniques. Signal lines at the RF ports should be
50 ohm impedance and the package ground leads
and package bottom should be connected directly
to the PCB RF ground plane, similar to that shown
above. The evaluation circuit board shown above is
available from Hittite Microwave Corporation upon
request.
List of Materials for Evaluation PCB 104091 [1]
Item Description
J1 - J2 PCB Mount SMA RF Connector
J3 - J7 DC PIN
U1 HMC346MS8G / HMC346MS8GE
PCB [2] 104089 Eval Board
[1] Reference this number when ordering complete evaluation PCB
[2] Circuit Board Material: Rogers 4350
HMC346MS8G / 346MS8GE
v07.1008
GaAs MMIC SMT VOLTAGE-VARIABLE
ATTENUATOR, DC - 8 GHz