Monolithic PIN SP4T Diode Switch
MASW-004100-1193
Rev. 2
Features
•
•
•
•
Ultra Broad Bandwidth: 50MHz to 26GHz
0.9 Insertion Loss , 34dB Isolation at 20GHz
50nS Switching Speed
Reliable, Fully Monolithic, Glass Encapsulated
Construction
Description
The MASW-004100-1193 is a SP4T series-shunt
broad band switch made with M/A-COM’s unique
HMIC
TM
(Heterolithic Microwave Integrated Circuit)
process, US Patent 5,268,310. This process allows the
incorporation of silicon pedestals that form series and
shunt diodes or vias by imbedding them in a low loss,
low dispersion glass. This hybrid combination of silicon
and glass gives HMIC switches exceptional low loss
and remarkable high isolation through low millimeter-
wave frequencies.
Applications
These high performance switches are suitable for use
in multi-band ECM, radar, and instrumentation control
circuits where high isolation to insertion loss ratios are
required. With a standard +5V/-5V, TTL controlled PIN
diode driver, 50nS switching speeds are achieved.
J3
J4
Absolute Maximum Ratings
T
AMB
=
+25°C ( Unless Otherwise Specified )
Parameter
Operating Temperature
Storage Temperature
RF C.W. Incident Power (± 20mA)
Bias Current ( Forward )
Applied Voltage ( Reverse )
Value
-65°C to +125°C
-65°C to +150°C
+33dBm
± 20mA
-25 Volts
J2
J5
J1
Notes:
Exceeding these limits may cause permanent
damage.
1
Monolithic Pin Diode Series-Shunt Switch
MASW-004100-1193
Rev 2
Electrical Specifications @ T
AMB
= +25
o
C, ± 20mA Bias Current
(On-Wafer Measurements)
Parameter
Insertion Loss
Isolation
Input Return Loss
Output Return Loss
Switching Speed
1
Frequency
20 GHz
20 GHz
20 GHz
20 GHz
10 GHz
Minimum
28
Nominal
0.9
34
15
15
50
Maximum
1.3
Units
dB
dB
dB
dB
nS
Notes:
1.) Typical switching speed is measured from 10% to 90% of detected RF voltage driven by a TTL compatible driver. Driver output
parallel RC network uses a capacitor between 390pF – 560pF and a resistor between 150Ω – 220Ω to achieve 50nS
rise and fall times.
Typical Driver Connections
Control Level ( DC Current ) at Port
J2
-20mA
+20mA
+20mA
+20mA
J3
+20mA
-20mA
+20mA
+20mA
J4
+20mA
+20mA
-20mA
+20mA
J5
+20mA
+20mA
+20mA
-20mA
Condition of
RF Output
J1-J2
Low Loss
Isolation
Isolation
Isolation
Condition of
RF Output
J1-J3
Isolation
Low Loss
Isolation
Isolation
Condition of
RF Output
J1-J4
Isolation
Isolation
Low Loss
Isolation
Condition of
RF Output
J1-J5
Isolation
Isolation
Isolation
Low Loss
Assembly Considerations
Cleanliness
Chips should be handled in a clean environment free of organic contamination.
Electro-Static Sensitivity
The MASW-004100-1193 PIN switch is ESD, Class 1A
procedures should be used.
sensitive (HBM). Proper ESD handling equipment and
Die Wire Bonding
Thermosonic wedge wire bonding using ¼ x 3 mil sq. ribbon or Ball Bonding using 1 mil diameter gold wire is
recommended. A stage temperature of 150°C and a force of 18 to 22 grams should be used. Ultrasonic energy should
be adjusted to the minimum required. RF bonds should be as short as possible.
Die Mounting
These chips have a Ti-Pt-Au back metal stack that can be die mounted using a gold-tin eutectic solder preform or
conductive Ag epoxy. Mounting surface must be clean and flat.
Eutectic Die Attachment
An 80/20 Gold-Tin eutectic solder preform is recommended with a work surface temperature of 255°C and a tool tip
temperature of 265°C. When hot gas is applied, the tool tip temperature should be ~290°C. The chip should not be
exposed to temperatures greater than 320°C for more than 20 seconds. No more than three seconds should be
required for the attachment.
Electrical Epoxy Die Attachment
Assembly should be preheated to 125-150°C. A controlled thickness of 2 mils is recommended for best electrical and
thermal conductivity. A thin epoxy fillet should be visible around the outer perimeter of the chip after placement to
ensure complete coverage. Cure epoxy per manufacturer’s schedule.
2
Typical Microwave
Performance
MASW-004100-1193 INSERTION LOSS
0.0
Loss (dB)
-0.5
-1.0
-1.5
-2.0
0.0
5.0
10.0
15.0
Frequency (GHz)
20.0
25.0
30.0
J1-J2
J1-J3
J1-J4
J1-J5
MASW-004100-1193 INPUT RETURN LOSS
0
-10
R. Loss (dB)
-20
J1-J2
-30
-40
-50
-60
0
5
10
15
20
25
30
J1-J3
J1-J4
J1-J5
Frequency (GHz)
3
Typical Microwave
Performance
MASW-004100-1193 OUTPUT RETURN LOSS
0
-5
R. Loss(dB)
-10
-15
-20
-25
-30
-35
0
5
10
15
Frequency (GHz)
20
25
30
J2
J3
J4
J5
MASW-004100-1193 ISOLATION
0
-10
-20
Isolation (dB)
-30
-40
-50
-60
-70
-80
-90
0
5
10
15
Frequency (GHz)
J1-J2
J1-J3
J1-J4
J1-J5
20
25
30
4
Operation of the MASW-004100-1193 PIN Switch
Operation of the MASW-004100-1193 PIN switch is achieved by the simultaneous application of negative DC current
to the low loss port and positive DC current to the remaining isolated switching ports as shown in Figure 1. The
backside area of the die is the RF and DC return ground plane. The DC return is achieved on the common port, J1.
The DC control currents should be supplied by constant current source. The voltages at these points will not exceed
±1.5 volts (1.2 volts typical) for supply currents up to ±20 mA. In the low loss state, the series diode must be forward
biased and the shunt diode reverse biased. For all the isolated ports, the shunt diode is forward biased and the series
diode is reverse biased. The bias network design should yield > 30 dB RF to DC isolation.
Best insertion loss, P1dB, IP3, and switching speed are achieved by using a voltage pull-up resistor in the DC return
path, (J1 ). A minimum value of |-2V| is recommended at this return node, which is achievable with a standard,
±5V TTL controlled PIN diode driver. A typical DC bias schematic for 2-18 GHz Operation is shown in Figure 1.
2 – 18 GHz Bias Network
J1
39 pF
22 pF
DC Bias
22nH
39 pF
100
Ω
22nH
HMIC Switch Die
J5
22 pF
J2
J4
Fig. 1
J3
5
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