参数资料
型号: HSMS-270B-TR1
英文描述: High Performance Schottky Diode for Transient Suppression
中文描述: 高性能肖特基二极管瞬态抑制
文件页数: 6/8页
文件大小: 116K
代理商: HSMS-270B-TR1
6
Applications Information
Schottky Diode Fundamentals
The HSMS-270x series of clipping/
clamping diodes are Schottky
devices. A Schottky device is a
rectifying, metal-semiconductor
contact formed between a metal
and an n-doped or a p-doped
semiconductor. When a metal-
semiconductor junction is formed,
free electrons flow across the
junction from the semiconductor
and fill the free-energy states in
the metal. This flow of electrons
creates a depletion or potential
across the junction. The differ-
ence in energy levels between
semiconductor and metal is called
a Schottky barrier.
P-doped, Schottky-barrier diodes
excel at applications requiring
ultra low turn-on voltage (such as
zero-biased RF detectors). But
their very low, breakdown-voltage
and high series-resistance make
them unsuitable for the clipping
and clamping applications involv-
ing high forward currents and high
reverse voltages. Therefore, this
discussion will focus entirely on
n-doped Schottky diodes.
Under a forward bias (metal
connected to positive in an
n-doped Schottky), or forward
voltage, V
F
, there are many
electrons with enough thermal
energy to cross the barrier poten-
tial into the metal. Once the
applied bias exceeds the built-in
potential of the junction, the
forward current, I
F
, will increase
rapidly as V
F
increases.
When the Schottky diode is
reverse biased, the potential
barrier for electrons becomes
large; hence, there is a small
probability that an electron will
have sufficient thermal energy to
cross the junction. The reverse
leakage current will be in the
nanoampere to microampere
range, depending upon the diode
type, the reverse voltage, and the
temperature.
In contrast to a conventional p-n
junction, current in the Schottky
diode is carried only by majority
carriers (electrons). Because no
minority-carrier (hole) charge
storage effects are present,
Schottky diodes have carrier
lifetimes of less than 100 ps. This
extremely fast switching time
makes the Schottky diode an ideal
rectifier at frequencies of 50 GHz
and higher.
Another significant difference
between Schottky and p-n diodes
is the forward voltage drop.
Schottky diodes have a threshold
of typically 0.3 V in comparison to
that of 0.6 V in p-n junction
diodes. See Figure 6.
P
N
CURRENT
0.6V
+
BIAS VOLTAGE
PN JUNCTION
CAPACITANCE
METAL
N
CURRENT
0.3V
+
BIAS VOLTAGE
SCHOTTKY JUNCTION
CAPACITANCE
Figure 6.
Through the careful manipulation
of the diameter of the Schottky
contact and the choice of metal
deposited on the n-doped silicon,
the important characteristics of
the diode (junction capacitance,
C
J
; parasitic series resistance, R
S
;
breakdown voltage, V
BR
; and
forward voltage, V
F
,) can be
optimized for specific applica-
tions. The HSMS-270x series and
HBAT-540x series of diodes are a
case in point.
Both diodes have similar barrier
heights; and this is indicated by
corresponding values of satura-
tion current, I
S
. Yet, different
contact diameters and epitaxial-
layer thickness result in very
different values of C
J
and R
S
. This
is seen by comparing their SPICE
parameters in Table 1.
Table 1. HSMS-270x and
HBAT-540x SPICE Parameters.
HSMS-
270x
25 V
6.7 pF
0.55 eV
10E-4 A
1.4E-7 A
1.04
0.65
0.6 V
2
0.5
HBAT-
540x
40 V
3.0 pF
0.55 eV
10E-4 A
1.0E-7 A
1.0
2.4
0.6 V
2
0.5
Parameter
BV
CJ0
EG
IBV
IS
N
RS
PB
PT
M
At low values of I
F
1 mA, the
forward voltages of the two
diodes are nearly identical.
However, as current rises above
10 mA, the lower series resistance
of the HSMS-270x allows for a
much lower forward voltage. This
gives the HSMS-270x a much
higher current handling capability.
The trade-off is a higher value of
junction capacitance. The forward
voltage and current plots illustrate
the differences in these two
Schottky diodes, as shown in
Figure 7.
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相关代理商/技术参数
参数描述
HSMS-270B-TR1G 功能描述:肖特基二极管与整流器 15 VBR 6.7 pF RoHS:否 制造商:Skyworks Solutions, Inc. 产品:Schottky Diodes 峰值反向电压:2 V 正向连续电流:50 mA 最大浪涌电流: 配置:Crossover Quad 恢复时间: 正向电压下降:370 mV 最大反向漏泄电流: 最大功率耗散:75 mW 工作温度范围:- 65 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:SOT-143 封装:Reel
HSMS-270B-TR2 制造商:AGILENT 制造商全称:AGILENT 功能描述:High Performance Schottky Diode for Transient Suppression
HSMS-270B-TR2G 功能描述:肖特基二极管与整流器 15 VBR 6.7 pF RoHS:否 制造商:Skyworks Solutions, Inc. 产品:Schottky Diodes 峰值反向电压:2 V 正向连续电流:50 mA 最大浪涌电流: 配置:Crossover Quad 恢复时间: 正向电压下降:370 mV 最大反向漏泄电流: 最大功率耗散:75 mW 工作温度范围:- 65 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:SOT-143 封装:Reel
HSMS-270C 制造商:未知厂家 制造商全称:未知厂家 功能描述:High Performance Schottky Diode for Digital Applications (79K in pdf)
HSMS-270C-BLK 制造商:AGILENT 制造商全称:AGILENT 功能描述:High Performance Schottky Diode for Transient Suppression