F0321818M Datasheet, PDF (9/10 Pages) Eudyna Devices Inc – 2 GHz Bandwidth Limiting Amplifier

2 GHz Limiting Amplifier
F0321818M
♦ Noise Performance
The F0321818M based on the GaAs FET fabrication process intrinsically has more ex-
cellent low-noise characteristics compared with IC’s based on the silicon bipolar process.
Many transmission systems often demand superior signal-to-noise ratio; the F0321818M is
the best choice for such applications.
The differential circuit configuration in the input and output enable a complete differential
operation to reduce common mode noise: simple single ended input and output operation is
also available.
♦ LPF+ & LPF-
The F0321818M has two terminals, LPF+ and LPF-, for AC ground. These terminals are
connected to ground by a capacitor. The time constant of the feedback loop in the
F0321818M depends on the capacitor, giving the lower frequency cutoff of the circuit by the
large capacitor. A 0.1 micro farad is employed for conventional applications.
♦ Packaging
The F0321818M is in an 18-lead metal-based flat package (MFP) about 300 mil square
with the lead pitch of 40 mil, achieving miniaturization and low cost. It is originally developed
by SEI to improve RF performance and heat radiation. Comparing with the SOP, the ground
potential steadier at microwave frequency range and the thermal receptivity is smaller due to
the metal based bottom structure made from CuW (an alloy of copper and tungsten) with a
high thermal conductivity. The intrinsic broad band performance of the F0321818M can not
be brought out by the standard SOP and LCC, because it is difficult to overcome impedance
mismatch at high frequency around 2 GHz. Therefore, SEI’s superior package technology
enable to achieve the excellent wide band limiting performance of the F0321818M.
♦ Precautions
Owing to their small dimensions, the GaAs FET’s from which the F0321818M is designed
are easily damaged or destroyed if subjected to large transient voltages. Such transients can
be generated by power supplies when switched on if not properly decoupled. It is also pos-
sible to induce spikes from static-electricity-charged operations or ungrounded equipment.