DATA SHEET
Silicon Schottky Barrier Diodes: Packaged, Bondable Chips
and Beam Leads
Applications
x Detectors
Features
x Available in both P-type and N-type low barrier silicon
x Low 1/f noise
x Bonded junctions for reliability
x Planar passivated beam-lead and chip construction
The choice of N- and P-type silicon allows the designer to
x Packages rated MSL1, 260 qC per JEDEC J-STD-020)
optimize the silicon material for the intended application:
x Doppler mixers and high-sensitivity detectors benefit from using
the low noise characteristics of the P-type silicon.
Skyworks offers lead (Pb)-free, RoHS (Restriction of
Hazardous Substances) compliant packaging.
x Low conversion loss mixers and biased detectors can be
designed using standard N-type material.
Description
Applications
Skyworks packaged, beam-lead and chip Schottky barrier
detector diodes are designed for applications through 40 GHz in
the Ka band. They are made by the deposition of a suitable barrier
metal on an epitaxial silicon substrate to form the junction. The
process and choice of materials result in low series resistance
along with a narrow spread of capacitance values for close
impedance control. P-type silicon is used to obtain superior 1/f
noise characteristics. N-type silicon is also available.
These diodes are categorized by Tangential Signal Sensitivity
(TSS) for detector applications in four frequency ranges: S, X, Ku,
and Ka bands. However, they can also be used as modulators,
high-speed switches, and low-power limiters.
TSS is a parameter that describes a diode’s detector sensitivity. It
is defined as the amount of signal power, below a one-milliwatt
reference level, required to produce an output pulse with an
amplitude sufficient to raise the noise fluctuations by an amount
equal to the average noise level. TSS is approximately 4 dB above
the minimum detectable signal.
Packaged diodes are suitable for use in waveguide, coaxial, and
stripline applications. Beam-lead and chip diodes can also be
mounted in a variety of packages or on special customer
substrates.
The P-type Schottky diodes in this Data Sheet are optimized for
low noise in the 1/f region. They require a small forward bias (to
reduce video resistance) if efficient operation is required. The bias
not only increases sensitivity but also reduces parameter variation
due to temperature change. Video impedance is a direct function
of bias and follows the 26/l (mA) relationship. This is important to
pulse fidelity, since the video impedance together with the
detector output capacitance affects the effective amplifier
bandwidth.
Unmounted beam-lead diodes are especially well suited for use in
Microwave Integrated Circuit (MIC) applications. Mounted beam-
lead diodes can be easily used in MIC, stripline, or other such
circuitry.
These “universal chips” are designed for a high degree of device
reliability in both commercial and industrial uses. The offset bond
pad assures that no mechanical damage occurs at the junction
during the wire bonding. Additionally, the 4 mil bond pad
eliminates performance variation due to bonding, improves
efficiency during manual operations, and is ideal for automated
assembly.
Bias does, however, increase typical noise, particularly in the 1/f
region. Therefore, it should be kept as low as possible (typically 5
to 50 μA).
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
200847B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • October 2, 2009
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