2 - 26
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
A
TTENU
A
T
ORS
2
SMT
General Description
SINGLE POSITIVE VOLTAGE CONTROL: 0 to +3V
HIGH ATTENUATION RANGE: >50 dB @ 0.9 GHz
HIGH P1dB COMPRESSION POINT: +16 dBm
ULTRA SMALL PACKAGE: MSOP
The HMC173MS8 is a miniature absorp-
tive voltage variable attenuator in an 8-
lead MSOP package. The device oper-
ates with a positive supply voltage, and a
positive control voltage. Unique features
include a high dynamic attenuation range,
and excellent power handling performance
through all attenuation states. The
HMC173MS8 is ideal for operation in wire-
less applications between 800 MHz and
1600 MHz. 1.7 to 2.0 GHz operation is
possible, with a reduced maximum attenu-
ation of 30 dB and increased VSWR. The
HMC173MS8 can be used with an exter-
nal driver circuit for improved linearity of
attenuation.
Features
Guaranteed Performance
V
dd
= +4.0 Vdc, 50 Ohm System, -40 to +85C
Parameter
Min
Typical
Max
Units
Insertion Loss (Min. Atten.)
(V
CTL
= 0.0 Vdc)
800-1000 MHz
1000-1600 MHz
1600-2000 MHz
1.8
2.6
3.2
2.3
3.1
3.7
dB
dB
dB
Attenuation Range
(V
CTL
= 0 to +3 V)
800-1000 MHz
1000-1600 MHz
1600-2000 MHz
45
27
25
52
32
30
dB
dB
dB
Flatness
(Peak to Peak)
800-1000 MHz
1000-1600 MHz
0.15
0.25
dB
dB
Return Loss
(V
CTL
= 0 to +3 V)
800-1000 MHz
1000-1600 MHz
1600-2000 MHz
6
5
5
12
8
7
dB
dB
dB
Input Power for 0.1 dB Compression
(825 MHz)
Min Atten.
Atten.>2.0
19
9
dBm
dBm
Input Power for 1.0 dB Compression
(825 MHz)
Min Atten.
Atten.>2.0
21
10
25
16
dBm
dBm
Input Third Order Intercept
825 MHz, two tones @ +5.0 dBm
Min Atten.
Atten.>2.0
30
15
37
21
dBm
dBm
Switching Characteristics
t
RISE
, t
FALL
(10/90% RF)
t
ON
, t
OFF
(50% CTL to 10/90% RF)
800-2000 MHz
1.0
1.2
S
S
GaAs MMIC VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
HMC173MS8
2 - 27
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
2
A
TTENU
A
T
ORS
SMT
Broadband Attenuation and
Insertion Loss
Broadband Return Loss vs.
Control Voltage
-60
-50
-40
-30
-20
-10
0
ATTENUATION (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
825 MHz
1900 MHz
10
15
20
25
30
35
40
825 MHz INPUT IP3 (dBm)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
+85C
+25C
-40C
-7
-6
-5
-4
-3
-2
-1
0
INSERTION LOSS (dB)
0.6
0.8
1
1.2
1.4
1.6
1.8
2
FREQUENCY (GHz)
-70
-60
-50
-40
-30
-20
-10
0
ATTENUATION (dB)
-20
-15
-10
-5
0
RETURN LOSS (dB)
0.6
0.8
1
1.2
1.4
1.6
1.8
2
FREQUENCY (GHz)
2V
0V
2.25V
3V
Attenuation vs. Control Voltage
@900 and 1900 MHz
HMC173MS8 VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
Input IP3 vs. Control Voltage
@825 MHz
-10
-8
-6
-4
-2
0
2
4
6
8
10
NORMALIZED ATTENUATION (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
-40C
+85C
Attenuation vs. Temperature
Normalized to +25C @825 MHz
Input Power For 1 dB Compression Point
Test Condition
(825MHz)
V
CTL
(Vdc)
Vdd
(Vdc)
+25C
+85C
-40C
Units
Min. Attenuation
0.0
+4.0
26
24
25
dBm
Max. Attenuation
+3.0
+4.0
16.5
15
23
dBm
Worst Case
P1dB @
Typical V
CTL
+1.8
+4.0
16.5
15.5
14
dBm
S - Parameter data is available On-Line at www.hittite.com
Input P1dB Compression
@825 MHz
HMC173MS8
2 - 28
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
A
TTENU
A
T
ORS
2
SMT
Attenuation vs. Control Voltage
825 MHz
Attenuation vs. Control Voltage
1900 MHz
Return Loss vs. Control Voltage
825 MHz
Return Loss vs. Control Voltage
1900 MHz
-60
-50
-40
-30
-20
-10
0
ATTENUATION (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
+25C
+85C
-40C
-35
-30
-25
-20
-15
-10
-5
0
ATTENUATION (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
+25C
+85C
-40C
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
RETURN LOSS (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
+25C
-40C
+85C
Typical Performance for 800-1000 MHz Applications
Typical Performance for 1800-1900 MHz Applications
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
RETURN LOSS (dB)
0
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (V)
+25C
-40C and +85C
HMC173MS8 VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
HMC173MS8
2 - 29
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
2
A
TTENU
A
T
ORS
SMT
V
CTL
-0.2 Vdc to Vdd
Vdd
+8 Vdc
Maximum Input Power
Vdd = +4.0 Vdc
+29 dBm
+21 dBm
Min Attenuation
Att. > 2 dB
Storage Temperature
-65 to +150 deg. C
Operating Temperature
-40 to +85 deg. C
Outline Drawing
Absolute Maximum Ratings
Control and Bias Voltages
V
L
T
C
0
0
1
-
@
c
d
V
0
.
3
+
o
t
0
0
0
1
+
o
t
A
A
d
d
V
0
0
1
+
@
c
d
V
1
.
0
-
/
+
c
d
V
0
.
4
+
A
HMC
173
XXXX
YYWW
DATE CODE
LOT NUMBER
YY= YEAR
WW= WEEK
PIN 1 (REF)
PIN 1
RF1
Gnd
0.116/ 0.120
0.116/ 0.120
0.188/ 0.196
0.0256 TYP
0.012 TYP
0.032/ 0.036
0.038/ 0.042
(2.95/ 3.05)
(4.78/ 4.98)
(2.95/ 3.05)
(0.65)
(0.30)
(0.81/ 0.91)
(0.96/ 1.07)
0.005/ 0.007
(0.13/ 0.18)
0 to 5 deg
0.021 MIN TYP
(0.53)
RF2
Vdd
N/C
Gnd
V
CTL
N/C
Functional Diagram
PIN 1
VCTL
RF2
Vdd
GND
N/C
N/C
GND
RF1
* NOTE: DC blocking capacitors are required for each RF port. Capacitor value
determines lowest frequency of operation.
HMC173MS8 VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
1. MATERIAL:
A) PACKAGE BODY - LOW STRESS INJECTION - MOLDED PLASTIC, SILICA & SILICONE IMPREGNATED.
B) LEADFRAME MATERIAL: COPPER ALLOY
2. PLATING: LEAD - TIN SOLDER PLATE
3. DIMENSIONS ARE IN INCHES (MILLIMETERS), UNLESS OTHERWISE SPECIFIED TOL. ARE 0.005(0.13)
4. TAPE AND REEL SHIPMENT PACKAGING AVAILABLE, SEE PAGE 10 - 1
HMC173MS8
2 - 30
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
A
TTENU
A
T
ORS
2
SMT
Part
Description
Manufacturer
AD822
Op-Amp
Analog Devices
R1
10K ohms
Panasonic
R2
200K ohms
Panasonic
R3
7.5K ohms
Panasonic
R4
39K ohms
Panasonic
R5
220K ohms
Panasonic
R6
91K ohms
Panasonic
R7
910 ohms
Panasonic
R8
51 ohms
Panasonic
R9
100 ohms
Panasonic
D1, D2
LL4148 D-35
Digikey
Attenuation Linearizing Control Circuit For The
HMC173MS8 Voltage Variable Attenuator
A driver circuit to improve the attenuation linearity of the HMC173MS8 can be implemented with a simple op-amp
configuration. A breakpoint linearization circuit will scale the voltage supplied to the control line of the HMC173MS8,
so that a more linear attenuation vs. control voltage slope can be achieved. A -5V and +5V supply is required.
Diode and resistor values which define the op-amp gain, and breakpoint were selected to optimize a measured
production lot of attenuators at 825 MHz. R7 may be varied to optimize the performance of any given attenuator. If the
input voltage to the linearizing circuit will not drop below 1.0V, then R9 and D2 may be omitted, and this will greatly reduce
the overall power consumption of the driver circuit.
The linearizing circuit has been optimized for 825 MHz attenuation applications. A similar approach may be used at other
frequencies by adjusting RI - R9 resistor values.
Required Parts List
Schematic
VCTL IN
R5
R8
R6
R1
R7
0
+5
0
3
7
2
D1
-5V
R4
R3
R2
4
AD820/AD
V+
V-
+
_
U3
6
D2
VCTL OUT
R9
+5V
-5V
HMC173MS8 VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
Attenuation vs. Control Voltage
@ 825 MHz
-60
-50
-40
-30
-20
-10
0
ATTENUATION (dB)
0
1
2
3
CONTROL VOLTAGE (Vdc)
Without
Linearizer
With
Linearizer
Return Loss vs. Control Voltage
@ 825 MHz
-19
-18
-17
-16
-15
-14
-13
-12
RETURN LOSS (dB)
0.5
1
1.5
2
2.5
3
CONTROL VOLTAGE (Vdc)
With
Linearizer
Without
Linearizer
HMC173MS8
2 - 31
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343
Fax: 978-250-3373
Web Site: www.hittite.com
MICROWAVE CORPORATION
F
EBRUARY
2001
2
A
TTENU
A
T
ORS
SMT
HMC173MS8 VOLTAGE VARIABLE ATTENUATOR 800-2000 MHz
The circuit board used in the final application should use RF circuit design techniques. Signal lines should have
50 ohm impedance while the package ground leads should be connected directly to the ground plane similar to
that shown below. A sufficient number of VIA holes should be used to connect the top and bottom ground planes.
The evaluation circuit board as shown is available from Hittite upon request.
Evaluation Circuit Board
Evaluation Circuit Board Layout Design Details
Layout Technique
Grounded Co-Planar Waveguide (GCPW)
Material
FR4
Dielectric Thickness
0.028" (0.71 mm)
50 Ohm Line Width
0.037" (0.94 mm)
Gap to Ground Edge
0.010" (0.25 mm)
Ground VIA Hole Diameter
0.014" (0.36 mm)
Connectors
SMA-F ( EF - Johnson P/N 142-0701-806)
HMC173MS8
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