HMPP-389x Series
MiniPak Surface Mount RF PIN Switch Diodes
Data Sheet
Description/Applications
These ultra-miniature products represent the blending of
Broadcom’s proven semiconductor and the latest in leadless
packaging technology.
The HMPP-389x series is optimized for switching applications
where low resistance at low current and low capacitance are
required. The MiniPak package offers reduced parasitics when
compared to conventional leaded diodes, and lower thermal
resistance.
Low junction capacitance of the PIN diode chip, combined with
ultra low package parasitics, means that these products can be
used at frequencies that are higher than the upper limit for
conventional PIN diodes.
Note that Broadcom’s manufacturing techniques assure that
dice packaged in pairs are taken from adjacent sites on the
wafer, ensuring the highest degree of match.
The HMPP-389T low inductance wide band shunt switch is well
suited for applications up to 6 GHz.
Minipak 1412 is a ceramic based package, while Minipak QFN is
a lead frame based package.
Features
Surface mount MiniPak package
Better thermal conductivity for higher power dissipation
Single and dual versions
Matched diodes for consistent performance
Low capacitance
Low resistance at low current
Low FIT (Failure in Time) rate
1
Six-sigma quality level
Pin Connections and Package Marking
3
4
AA
2
1
Product code
Date code
Package Lead Code Identification
(Top View)
Single
3
4
3
Anti-parallel
4
3
Parallel
4
Note: Package marking provides orientation and identification.
See Electrical Specifications for appropriate package marking.
2
#0
(Minipak 1412)
1
2
#2
(Minipak 1412)
1
2
#5
(Minipak 1412)
1
Shunt Switch
Cathode
Anode
3
4
2
Anode
T
Cathode
1
1.
For more information, see the Surface Mount Schottky
Reliability Data Sheet.
Broadcom
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HMPP-389x Series
Data Sheet
HMPP-389x Series Absolute Maximum Ratings, T
C
= 25°C
Operation in excess of any one of these conditions may result in permanent damage to the device.
Parameter
Forward Current (1-μs pulse)
Peak Inverse Voltage
Junction Temperature
Storage Temperature
Thermal Resistance
a
a.
Symbol
I
f
P
IV
T
j
T
stg
θ
jc
MiniPak 1412/
MiniPak QFN
1
100
150
–65 to +150
150
Unit
A
V
°C
°C
°C/W
T
C
= +25°C, where T
C
is defined to be the temperature at the package pins where contact is made to the circuit board.
CAUTION
Handling precautions should be taken to avoid static discharge.
MiniPak1412 Electrical Specifications, T
C
= +25°C, Each Diode
Part Number
HMPP-
3890
3892
3895
389T
Test Conditions
Package
Marking Code
D
C
B
T
Lead Code
0
2
5
T
Configuration
Single
Anti-parallel
Parallel
Shunt Switch
V
R
= V
BR
Measure I
R
≤ 10 μA
I
F
= 10 mA
f = 100 MHz
V
R
= 5V
f = 1 MHz
Minimum
Breakdown Voltage
(V)
100
Maximum Series
Resistance
(Ω)
2.5
Maximum Total
Capacitance
(pF)
0.30
MiniPak1412 Typical Parameters, T
C
= +25°C
Part Number
HMPP-
389x
Test Conditions
Series Resistance
R
S
(Ω)
3.8
I
F
= 1 mA
f = 100 MHz
Carrier Lifetime
τ (ns)
200
I
F
= 10 mA
I
R
= 6 mA
Total Capacitance
C
T
(pF)
0.20 at 5V
Broadcom
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HMPP-389x Series
Data Sheet
MiniPak 1412 HMPP-389x Series Typical Performance
T
C
= +25 °C (unless otherwise noted), each diode.
Figure 1 Total RF Resistance at 25°C vs. Forward Bias Current
Figure 2 Capacitance vs. Reverse Voltage
0.50
0.45
RF RESISTANCE (OHMS)
10
TOTAL CAPACITANCE (pF)
0.40
0.35
0.30
0.25
0.20
1 GHz
0.15
0.1
1
10
100
I
F
– FORWARD BIAS CURRENT (mA)
0
4
8
12
16
20
1 MHz
1
V
R
– REVERSE VOLTAGE (V)
Figure 3 Second Harmonic Input Intercept Point vs. Forward Bias
Current
120
INPUT INTERCEPT POINT (dBm)
Diode Mounted as a
Series Attenuator in a
115
50 Ohm Microstrip and
Tested at 123 MHz
110
Intercept point
will be higher
at higher
frequencies
Figure 4 Typical Reverse Recovery Time vs. Reverse Voltage
200
T
rr
– REVERSE RECOVERY TIME (nS)
160
V
R
= –2V
120
105
100
95
90
85
1
80
V
R
= –5V
40
V
R
= –10V
0
10
15
20
25
30
10
I
F
– FORWARD BIAS CURRENT (mA)
30
FORWARD CURRENT (mA)
Figure 5 Forward Current vs. Forward Voltage
100
I
F
– FORWARD CURRENT (mA)
10
1
0.1
0.01
125 C
0
0.2
0.4
25 C –50 C
0.6
0.8
1.0
1.2
V
F
– FORWARD VOLTAGE (V)
Broadcom
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HMPP-389x Series
Data Sheet
Typical Applications
Figure 6 Simple SPDT Switch Using Only Positive Bias
RF COMMON
Figure 7 High Isolation SPDT Switch Using Dual Bias
RF COMMON
2
1
RF 1
3
RF 1
3
4
3
4
RF 2
1
4
RF 2
2
1
2
BIAS 1
BIAS 2
BIAS
Figure 8 Very High Isolation SPDT Switch, Dual Bias
RF COMMON
Figure 9 PIN Diode Construction
N+ Diffusion
Metal Contact
Bulk
I-Layer
Bulk Attenuator Diode
4
3
RF 1
4
1
3
1
2
3
4
1
RF 2
P+ Diffusion
Epi
I-Layer
Contact Over
P+ Diffusion
2
2
Epi Switching Diode
N+ Substrate
BIAS
Broadcom
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HMPP-389x Series
Data Sheet
Application Information
PIN Diodes
In RF and microwave networks, mechanical switches and
attenuators are bulky, often unreliable, and difficult to
manufacture. Switch ICs, while convenient to use and low in
cost in small quantities, suffer from poor distortion
performance and are not as cost effective as PIN diode
switches and attenuators in very large quantities. For over 30
years, designers have looked to the PIN diode for high
performance/low cost solutions to their switching and level
control needs.
In the RF and microwave ranges, the switch serves the simple
purpose that is implied by its name; it operates between one of
two modes, ON or OFF. In the ON state, the switch is designed
to have the least possible loss. In the OFF state, the switch must
exhibit a very high loss (isolation) to the input signal, typically
from 20 dB to 60 dB. The attenuator, however, serves a more
complex function. It provides for the
soft
or controlled variation
in the power level of a RF or microwave signal. At the same
time as it attenuates the input signal to some predetermined
value, it must also present a matched input impedance (low
VSWR) to the source. Every microwave network that uses PIN
diodes (phase shifter, modulator, etc.) is a variation on one of
these two basic circuits.
You can see that the switch and the attenuator are quite
different in their function, and therefore often require different
characteristics in their PIN diodes. These properties are easily
controlled through the way in which a PIN diode is fabricated.
See
Figure 14.
Table 1 Bulk and EPI Diode Characteristics
Characteristic
Lifetime
Distortion
Current Required
I Region Thickness
EPI Diode
Short
High
Low
Very Thin
Bulk Diode
Long
Low
High
Thick
As discussed in the following paragraphs, the bulk diode is
almost always used for attenuator applications and sometimes
as a switch, while the epi diode (such as the HMPP-3890) is
generally used as a switching element.
Diode Lifetime and Its Implications
The resistance of a PIN diode is controlled by the conductivity
(or resistivity) of the I layer. This conductivity is controlled by
the density of the cloud of carriers (charges) in the I layer
(which is, in turn, controlled by the DC bias). Minority carrier
lifetime, indicated by the Greek symbol τ, is a measure of the
time it takes for the charge stored in the I layer to decay, when
forward bias is replaced with reverse bias, to some
predetermined value. This lifetime can be short (35 ns to 200 ns
for epitaxial diodes) or it can be relatively long (400 ns to
3000 ns for bulk diodes). Lifetime has a strong influence over a
number of PIN diode parameters, among which are distortion
and basic diode behavior.
To study the effect of lifetime on diode behavior, we first define
a cutoff frequency f
C
= 1/τ. For short lifetime diodes, this cutoff
frequency can be as high as 30 MHz while, for our longer
lifetime diodes, f
C
≅
400 kHz. At frequencies that are ten times
f
C
(or more), a PIN diode does indeed act like a current
controlled variable resistor. At frequencies that are one tenth
(or less) of f
C
, a PIN diode acts like an ordinary PN junction
diode. Finally, at 0.1 f
C
≤ f ≤ 10 f
C
, the behavior of the diode is
very complex. Suffice it to mention that in this frequency
range, the diode can exhibit very strong capacitive or inductive
reactance—it will not behave at all like a resistor. However, at
zero bias or under heavy forward bias, all PIN diodes
demonstrate very high or very low impedance (respectively) no
matter what their lifetime is.
Diode Construction
At Broadcom, two basic methods of diode fabrication are used.
In the case of bulk diodes, a wafer of very pure (intrinsic) silicon
is heavily doped on the top and bottom faces to form P and N
regions. The result is a diode with a very thick, very pure I
region. The epitaxial layer (or EPI) diode starts as a wafer of
heavily doped silicon (the P or N layer), onto which a thin I layer
is grown. After the epitaxial growth, diffusion is used to add a
heavily doped (N or P) layer on the top of the epi, creating a
diode with a very thin I layer populated by a relatively large
number of imperfections.
These two different methods of design result in two classes of
diode with distinctly different characteristics, as shown in
Table 1.
Diode Resistance vs. Forward Bias
In
Figure 15,
note that the typical curves for resistance vs.
forward current for bulk and epi diodes are very different. Of
course, these curves apply only at frequencies >10 f
C
. You can
see that the curve of resistance vs. bias current for the bulk
diode is much higher than that for the epi (switching) diode.
Thus, for a given current and junction capacitance, the epi
Broadcom
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