diodes are surrounded by a glass frame for superior
strength and electrical performance that surpasses
the standard beam lead PINs. They are designed for
low resistance, low capacitance and fast switching
time. The oxide–nitride passivation layers provide
reliable operation and stable junction parameters that
provide complete sealing of the junction permitting
use in assemblies with some degree of moisture
sealing. A layer of glass provides increased
mechanical strength.
Alpha’s beam lead PIN diodes are ideal for microstrip
or stripline circuits and for circuits requiring high
isolation from a series mounted diode such as broad
band multi–throw switches, phase shifters, limiters,
attenuators and modulators.
Electrical Specifications at 25°C
Low Capacitance Planar Beam Lead Diodes
Breakdown
Voltage
@ 10
µA
(V)
Min.
DSG6405–000
100
Typ.
125
Capacitance
Total
@ 50 Volts,
1 MHz
(pF)
Typ.
0.017
Max.
0.02
Series
Resistance
@ 20 mA
100 MHz
(Ohms)
Typ.
4.5
Max.
6.0
Minority Carrier
Lifetime
I
F
= 10mA, I
R
= 6mA
(ns)
Typ.
200
Reverse Recovery
Time
I
F
= 20 mA,
V
R
= 10V,
90% Recovery
(ns)
Typ.
20
Max.
35
389–004
Part
Number
Outline
Drawing
Number
4–16
Alpha Industries
•
[617] 935 5150
•
Fax
[617] 824 4579
•
E-mail
sales@alphaind.com
•
Visit our web site:
www.alphaind.com
Planar and Mesa Beam Lead PIN Diodes
DSG6405–000, DSG6474–000, DSM6300 Series
Performance Data for DSG6405–000
100
10K
Forward Current (mA)
10
RF Resistance (Ohms)
0.25
0.50
0.75
1.00
Forward Voltage (V)
1.25
1K
1
100
0.1
10
0.01
1
0.1
1
10
Forward Bias Current (mA)
100
Figure 1. Typical Forward Characteristics
Figure 3. Typical RF Resistance vs. Forward
Bias Current
4
0.08
0.06
Capacitance (pF)
Isolation Loss (dB)
0.04
45
40
35
30
25
20
15
10
5
0
Insertion Loss (dB)
(10 Volts)
0.02
1 MHz
Above 1 GHz
(20 mA)
0.75
0.60
0.45
0.30
0.15
30
0
0
10
20
Reverse Voltage (Volts)
30
0
5
15 18 20
10
Frequency (GHz)
25
Figure 2. Typical Capacitance vs. Reverse
Bias Voltage
Figure 4. Typical Insertion Loss and Isolation
Characteristics
Electrical Specifications at 25°C
Planar Beam Lead Diodes
Voltage
Breakdown
@ 10 mA
Min.
"DSG6474–000
200
Series Resistance
(Ohms) (From
Insertion Loss @
3 GHz, 50 mA)
1
Max.
4.0
Junction
Capacitance
C
J
(pF)
Max.
0.02
RF
Switching
Time
T
S
(ns)
2
25
Minority
Carrier
Lifetime
(ns)
Typ.
250
169–001
Part
Number
Outline
Drawing
Number
"
Available through distribution.
1. Total capacitance calculated from isolation at 9 GHz zero bias. Series resistance and capacitance are measured at microwave frequencies on a sample basis from each lot.
All diodes are characterized for capacitance at –50 Volts, 1 MHz, and series resistance at 1 KHz, 50 mA, measurements which correlate well with microwave measurements.
2. T
S
measured from RF transition, 90% to 10%, in series configuration.
Alpha Industries
•
[617] 935 5150
•
Fax
[617] 824 4579
•
E-mail
sales@alphaind.com
•
Visit our web site:
www.alphaind.com
4–17
Planar and Mesa Beam Lead PIN Diodes
DSG6405–000, DSG6474–000, DSM6300 Series
Performance Data for DSG6474–000
Figures 5 and 6 show a single pole double–throw
1–18 GHz switch these diodes are mounted an
Alumina, Duriod, or Teflon fiberglass 50 ohm
microstrip circuits. Typical bonding methods include
thermal compression bonding, parallel gap welding,
and soldering.
SPDT isolation curves are shown in Figure 6 and
insertion loss in Figures 7 and 8. With proper
transitions and bias circuits, VSWR is better than 2.0
to 1 through 18 GHz.
38
36
32
Isolation Loss (dB)
28
24
20
16
12
8
0
0
2
4
6
8
10 12 14 16 18
Frequency (GHz)
DSG6474–000
Switching Considerations
The typical minority carrier lifetime of the DSG6474
diodes is 100 ns. With suitable drivers, the individual
diodes can be switched from high impedance (off) to
low R
S
(on) in about 10 ns.
Beam Lead Pin
Duriod Substrate
50 Ohm
Glass Bead
Figure 7. Isolation vs. Frequency, SPDT
DSG6474–000
Figure 5. Typical SPDT Circuit Arrangement
2.0
Insertion Loss (dB)
1.5
1.0
DSG6474–000
0.5
Metal Conductor
Figure 6. Typical Beam Lead Mounting
4–18
Alpha Industries
•
[617] 935 5150
•
Fax
[617] 824 4579
•
E-mail
sales@alphaind.com
•
Visit our web site:
www.alphaind.com
ÇÇÇÇÇÇÇÇÇÇ
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ÉÉ
É
ÇÇÇÇÇÇÇ
ÉÉ
É
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É
ÇÇÇÇÇÇÇÇ
É
ÇÇ
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Ç
Beam Lead Pin
0.005”
50 Ohm
Transmission
Line
Connecting
Lead
2.5
Preferred Beam
Lead Orientation
0
0
10
50
Bias Current (mA)
100
Duroid
Figure 8. Diode Insertion Loss vs. Bias SPST,
18 GHz DSG6474–000
Planar and Mesa Beam Lead PIN Diodes
DSG6405–000, DSG6474–000, DSM6300 Series
Power Handling for DSG6474–000
Beam lead diodes are not suitable for high power
operation because of high internal thermal
impedance of about 600°C/Watt.
1.4
1.2
1.0
Isolation Loss (dB)
0.8
0.6
0.4
0.2
0
0
2
4
6 8 10 12 14 16 18
Frequency (GHz)
For pulsed operation, the total RF plus bias voltage
must not exceed the rated breakdown. Alpha has
made high power tests at 1 GHz with 1µs pulses,
0.001 duty, with 200V diodes. With 50 mA forward
bias, there is no increase in insertion loss over the 0
dBm level with a peak power input of 50 watts. In the
open state, reverse bias voltage is required to keep
the diode from “rectifying,” with resultant decrease in
isolation and possible failure. Figure 11 shows
allowed peak power versus reverse bias at 1 GHz.
At this frequency, the required reverse voltage is
almost equal to the peak RF voltage; at high
frequency, the bias can be reduced somewhat.
Experimentation is necessary.
100
80
Peak Power Watts
60
40
20
0
0
10
50
Reverse Bias (Volts)
100
4
Figure 9. Diode Insertion Loss vs. Frequency
SPST, 50 mA Bias DSG6474–000
With maximum CW power dissipation of 250 mW, the
DSG6474–000 diodes are normally rated at 2 Watt
CW with linear derating between 25°C and 150°C.
Figure 10 presents data on CW power handling as a
function of bias and frequency.
5000
0.4V
0.1V
2000
Figure 11. Peak Power Handling, SPST, 1 GHz
DSG6474–000
CW Power (Milliwatts)
1000
500
200
100
50
20
0.1 0.2 0.5 1.0 2.0 5.0
Frequency (GHz)
10
20
10% increase in
small signal
insertion loss
when biased at
50 mA.
10% decrease in
small signal insertion
loss when biased at
–1V/–4V.
Figure 10. Typical Series Switch Behavior at
Room Temperature and Biased at 50ma/1V/4V
DSG6474–000
Alpha Industries
•
[617] 935 5150
•
Fax
[617] 824 4579
•
E-mail
sales@alphaind.com
•
Visit our web site:
www.alphaind.com
4–19
Planar and Mesa Beam Lead PIN Diodes
DSG6405–000, DSG6474–000, DSM6300 Series
Mesa Beam Lead Diode Specifications
Voltage
Breakdown
@ I
R
< 10 mA
(V)
Max.
Fast Beam Lead Pin Diodes
"
DSM6380–000
DSM6381–000
100
150
0.025
0.025
3.5
4.0
4.5
5.0
40
50
389–003
389–003
Capacitance
Total
50V, 1MHz
(pF)
Max.
Series Resistance (Ohms)
50 mA,
100 MHz
Max.
10 mA,
100 MHz
Typ.
C
LT
I
F
= 10 mA,
mA
I
R
= 6 mA
(ns)
Typ.
O tli
Outline
Drawing
Number
Part
Number
Low–Loss Ultra–Fast Beam Lead PIN Diodes
DSM6361–000
60
0.025
1
3.5
2
––
25
389–003
"
Available through distribution.
1. Capacitance Total @ 10 Volts, 1 MHz, pF, Max.
2. Series Resistance @ 10 mA, Ohms, Max., 100 MHz.
Part
Number
Voltage
Breakdown @ 10
µA,
Reverse Current
Min.
Typ.
Series Resistance
@ 50 MHz, 50 mA
Typ.
Max.
Capacitance Total
@ –10V, 1 MHz
Typ.
Max.
Lifetime
(ns)
Typ.
1
Switching
Time
(ns)
Typ.
2
Video
Recovery
Time
(ns)
2
Outline
Drawing
Number
Ultra Low Resistance High–Speed Beam Lead PIN Diodes
DSM6356–000
30
50
1.2
1.5
0.12
0.15
30
5
2
389–003
1. I
F
= 10mA, I = 6mA, recovery to 3 mA.
2. Video recovery time at 2 GHz from I
F
= 10mA to V
R
= 10V, from 100% to 10% in series configuration. Video reverse recovery time from I
