F0321818Q Datasheet, PDF (10/11 Pages) Eudyna Devices Inc – 2 GHz Bandwidth Limiting Amplifier

F0321818Q
♦ Noise Performance
2GHz Limiting Amplifier
The F0321818Q 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 F0321818Q 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 F0321818Q 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
F0321818Q depends on the capacitor, giving the lower frequency cutoff of the circuit by the
large capacitor. A 0.1micro farad is employed for conventional applications.
♦ Packaging
The F0321818Q is in an 20-lead quadruplel flat package (QFP) about 350 mil square
with the lead pitch of 32 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 Cu with a high thermal conductivity. The intrin-
sic broad band performance of the F0321818Q 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 F0321818Q.
♦ Precautions
Owing to their small dimensions, the GaAs FET’s from which the F0321818M is de-
signed are easily damaged or destroyed if subjected to large transient voltages. Such tran-
sients can be generated by power supplies when switched on if not properly decoupled. It is
also possible to induce spikes from static-electricity-charged operations or ungrounded
equipment.