HSMS-286C-TR1 Avago Technologies US Inc., HSMS-286C-TR1 Datasheet - Page 12

• Manufacturer Part Number: HSMS-286C-TR1
• Description: DETECTOR DIODE,SOT-323
• Manufacturer: Avago Technologies US Inc.

Specifications of HSMS-286C-TR1

• Rohs Compliant: NO
• Diode Type: Schottky - 1 Pair Series Connection
• Voltage - Peak Reverse (max): 4V
• Capacitance @ Vr, F: 0.25pF @ 0V, 1MHz
• Package / Case: SC-70-3, SOT-323-3
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Max: -
• Power Dissipation (max): -
• Resistance @ If, F: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Other configurations of six lead
Schottky products can be used to
solve circuit design problems
while saving space and cost.
Thermal Considerations
The obvious advantage of the
SOT-363 over the SOT-143 is
combination of smaller size and
two extra leads. However, the
copper leadframe in the SOT-323
and SOT-363 has a thermal
conductivity four times higher
than the Alloy 42 leadframe of the
SOT-23 and SOT-143, which
enables it to dissipate more
power.
The maximum junction tempera-
ture for these three families of
Schottky diodes is 150°C under
all operating conditions. The
following equation, equation 1,
applies to the thermal analysis of
diodes:
Equation (1).
where
Note that θ
tance from diode junction to the
foot of the leads, is the sum of
two component resistances,
Equation (2).
T
T
T
θ
V
P
θ
jc
j
a
jc
f
RF
j
I
= (V
= junction temperature
= diode case temperature
f
= θ
= thermal resistance
= RF power dissipated
= DC power dissipated
pkg
f
I
jc
f
+ θ
+ P
, the thermal resis-
chip
RF
) θ
jc
+ T
a
Package thermal resistance for
the SOT-323 and SOT-363 pack-
age is approximately 100°C/W,
and the chip thermal resistance
for these three families of diodes
is approximately 40°C/W. The
designer will have to add in the
thermal resistance from diode
case to ambient — a poor choice
of circuit board material or heat
sink design can make this number
very high.
Equation (1) would be straightfor-
ward to solve but for the fact that
diode forward voltage is a func-
tion of temperature as well as
forward current. The equation,
equation 3, for V
I
Equation (3).
where
and I
is given by
I
Equation (4).
Equations (1) and (3) are solved
simultaneously to obtain the
value of junction temperature for
given values of diode case
temperature, DC power dissipa-
tion and RF power dissipation.
[6]
f
s
= I
= I
Agilent Application Note 1050, Low Cost, Surface Mount Power Limiters.
n = ideality factor
T = temperature in °K
R
s
S
0
S
= diode series resistance
(
(diode saturation current)
e
298
11600 (V
T
)
2
n – 4060
e
nT
f
f
is:
– I
f
R
(
s
1
)
T
– 1
–
298
1
)
Diode Burnout
Any Schottky junction, be it an RF
diode or the gate of a MESFET, is
relatively delicate and can be
burned out with excessive RF
power. Many crystal video
receivers used in RFID (tag)
applications find themselves in
poorly controlled environments
where high power sources may be
present. Examples are the areas
around airport and FAA radars,
nearby ham radio operators, the
vicinity of a broadcast band
transmitter, etc. In such
environments, the Schottky
diodes of the receiver can be
protected by a device known as a
limiter diode.
available only in radar warning
receivers and other high cost
electronic warfare applications,
these diodes have been adapted to
commercial and consumer
circuits.
Agilent offers a complete line of
surface mountable PIN limiter
diodes. Most notably, our HSMP-
4820 (SOT-23) or HSMP-482B
(SOT-323) can act as a very fast
(nanosecond) power-sensitive
switch when placed between the
antenna and the Schottky diode,
shorting out the RF circuit
temporarily and reflecting the
excessive RF energy back out the
antenna.
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[6]
Formerly