5 of 8DS091020
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SDA-1000
Pin Function Description Interface Schematic
1RFIN
RF Input. This pad is DC coupled and matched to 50 from DC to 20GHz. 50
microstrip transmission line on 0.127mm (5mil) thick alumina thin film sub-
strate is recommended for RF input and output.
2VG2
VG2 is an optional pad. It may be used to bias the cascode gate of the amplifier.
If this port is used, a 1000pF bypass capacitor with the shortest wirebond length
possible is recommended to prevent low frequency gain ripple.
3VTO
The output drain termination pad. This pad requires a suggested 1000pF bypass
capacitor with the shortest wirebond length to prevent low frequency gain ripple.
The value of the external capacitance limits the low frequency response of the
amplifier.
4RFOUT and
VDD
RF Output. 50 microstrip transmission line on 0.127mm (5mil) thick alumina
thin film substrate is recommended for RF input and output. Connect the DC bias
(V
DD
) network to provide drain current (I
DD
).
5VCAS
Provides VG2 gate voltage to the cascode amplifier. The value is ~ (V
CC
/2 - abso-
lute value of VTI).
6VG21
Not connected.
7VTI
Input gate voltage, used to bias the amplifier. The value is between -1.5V
DC
(device is pinched OFF) to +0.2V
DC
(fully ON). This pad requires a bypass capaci-
tor to ground with the shortest possible wirebond length to prevent low frequency
gain ripple. The value of the external capacitance limits the low frequency
response of the amplifier.
Die GND Ground connection. Connect die bottom directly to ground plane for best perfor-
mance. NOTE: The die should be connected directly to the ground plane with con-
ductive epoxy.
RFOUT
VDD
Note: Drain Bias (VDD) must be applied
through a broadband bias tee or
external bias network