AMMC-5026_08 Datasheet, PDF (7/8 Pages) AVAGO TECHNOLOGIES LIMITED – 2-35 GHz GaAs MMIC Traveling Wave Amplifier

Biasing and Operation
AMMC-5026 is biased with a single positive drain supply
(V_d) and a negative gate supply (V_g1). The recommended
bias conditions for the AMMC-5026 is V_dd = 7 V and I_dd =
150 mA for best overall performance. Open circuit is the
default setting for the V_g2 biasing.
Figure 17 shows a typical bonding configuration for the 2
to 35 GHz operations. In this case, auxiliary drain and V_g1
capacitors (>0.5 µF) are used for low frequency (below
2 GHz) performance. Input and output RF ports are DC
coupled; therefore, DC decoupling capacitors are required
if there are DC paths.
The auxiliary gate and drain contacts are used for low
frequency performance extension below 1 GHz. When
used, these contacts must be AC coupled only. (Do not
attempt to apply bias to these pads.)
Ground connections are made with plated through-holes
to the backside of the device.
Assembly Techniques
The backside of the MMIC chip is RF ground. For mi­crostrip
applications the chip should be attached directly to
the ground plane (e.g. circuit carrier or heatsink) using
electrically conductive epoxy . ^[1,2] For conductive epoxy,
the amount should be just enough to provide a thin fil-
let around the bottom perimeter of the die. The ground
plane should be free of any residue that may jeopardize
electrical or mechanical attachment. Caution should be
taken to not exceed the Absolute Maximum Rating for
assembly temperature and time.
Thermosonic wedge bonding is the preferred method for
wire attachment to the bond pads. The RF connections
should be kept as short as possible to minimize inductance.
Gold mesh or double-bonding with 0.7 mil gold wire is
recommended.
Mesh can be attached using a 2 mil round tracking tool
and a tool force of approximately 22 grams with an ul-
trasonic power of roughly 55 dB for a duration of 76 ± 8
mS. A guided wedge at an ultrasonic power level of 64
dB can be used for the 0.7 mil wire. The recommended
wire bond stage temperature is 150 ± 2°C.
The chip is 100 mm thick and should be handled with
care.
This MMIC has exposed air bridges on the top surface.
Handle at edges or with a custom collet (do not pick up
die with vacuum on die center.)
This MMIC is also static sensitive and ESD handling precau-
tions should be taken.
Notes:
1. Ablebond 84-1 LM1 silver epoxy is recommended.
2. Eutectic attach is not recommended and may jeopardize reliability
of the device.
Vd
RF Output
Aux Vd
Aux Vg2
RF Input
Figure 15. AMMC-5026 Schematic.

Vg1
Aux Vg1