SDA-2000 Datasheet, PDF (6/8 Pages) RF Micro Devices – GaAs Distributed Amplifier

SDA-2000
Pin Names and Descriptions
Pin
Name
Description
RF Input. This pad is DC coupled and matched to 50Ω from DC to
22GHz. 50Ω microstrip transmission line on 0.127mm (5mil) thick
1
RFIN
alumina thin film substrate is recommended for RF input and
output. A DC blocking capacitor is required for this connection. The
calue of this capacitor will be based on the desired frequency range
of application.
Each amplifier stage in the SDA-2000 is a cascade configuration.
The gate of each upper FET in the cascade amplifiers is biased
with the 3.5VDC (for VDD = 8V). The DC connection for the upper
2
VG2
device gates runs across the length of the die. Pads 2 and 5 are
both on this DC connection but are on opposite ends of the die.
The VG2 connection can therefore be placed on either pad. A
bypass capacitor is recommended on both ends, pads 2 and 5.
The output drain termination pad. This pad requires a 1000pF
3
VTO
bypass capacitor with the shortest wirebond length to prevent low
frequency gain ripple.
Interface Schematic
RF Output. 50Ω microstrip transmission line on 0.127mm (5mil)
RFOUT and
thick alumina thin film substrate is recommended for RF input and
4
VDD
output. Connect the DC bias (VDD) network to provide drain current
(IDD). Note: Drain Bias (VDD) must be applied through a broadband
bias tee or external bias network.
Each amplifier stage in the SDA-2000 is a cascade configuration.
The gate of each upper FET in the cascade amplifiers is biased
with the 3.5VDC (for VDD = 8V). The DC connection for the upper
5
VCAS
device gates runs across the length of the die. Pads 2 and 5 are
both on this DC connection but are on opposite ends of the die.
The VG2 connection can therefore be placed on either pad. A
bypass capacitor is recommended on both ends, pads 2 and 5.
6
VG21
Not connected.
Input gate voltage for the lower devices in the cascade amplifier.
This pad also serves as the RF ground for the input termination
7
VTI
resistor. The DC voltage applied to this pad will be between -2.0VDC
(device is pinched OFF) to 0VDC (fully ON). The value of this
capacitor will effect the low frequency response of the amplifier.
Ground connection. Connect die bottom directly to ground plane for
Die
GND
best performance. NOTE: The die should be connected directly to
the ground plane with conductive epoxy.
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421
DS140204
For sales or technical support, contact RFMD at +1.336.678.5570 or [e-mail].
The information in this publication is believed to be accurate. However, no responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any infringement of patents or other rights of
third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent rights of RFMD. RFMD reserves the right to change component circuitry, recommended
application circuitry and specifications at any time without prior notice.
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