BFQ790 Datasheet, PDF (7/30 Pages) Infineon Technologies AG – High Linearity High Gain 1/2 Watt RF Driver Amplifier

BFQ790
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Product Brief
Product Brief
The BFQ790 is a single stage high linearity high gain driver amplifier. The device is not internally matched and
hence provides flexibility to be used for any application where high linearity is key. There are several application
notes available, most of them for LTE frequencies, a summary can be found in chapter 6. The device is based on
Infineon's reliable and cost effective NPN silicon germanium technology running in very high volume. The
technology comprises lowohmic substrate contacts so that emitter bond wires can be omitted. Thereby the emitter
inductance is minimized and the power gain optimized. For example one of the circuits provides an OIP3 of
41 dBm at 2650 MHz, with a power gain of 14 dB.
The datasheet describes the device mainly at 250 mA collector current IC, operated in Class A mode. Under these
conditions the BFQ790 provides ½ Watt RF power and highest linearity. If energy efficiency is in the focus it is
recommended to operate the device in class AB mode. That means to adjust a quiescent current ICq lower than
250 mA and use the self biasing effect to get high linearity and efficiency when the input RF power is high. Please
refer to figure 7-19, where as an example an ICq of 155 mA is adjusted. OIP3 vs. IC is shown in figure 7-22.
For the BFQ790 an advanced large signal compact model is available. Further information please find in chapter 8.
The BFQ790 is very rugged. A special collector design prevents from thermal runaway respectively 2nd
breakdown. This leads to a high ruggedness against mismatch at the output. The collector design allows safe
operation with a single 5 V supply. The special design of the emitter-base diode makes the input robust and yields
a high maximum RF input power.
The chip is housed in a halogen free industry standard package SOT89. The high thermal conductivity of the
silicon substrate and the low thermal resistance of the package add up to a thermal resistance of only 35 K/W,
what leads to moderate junction temperatures even at high dissipated DC power values. Recommended operating
conditions can be found in chapter 4. The proper die attach with good thermal contact is tested 100%, so that there
is a minimum variation of thermal properties. The devices are 100% DC and RF tested.
Preliminary Data Sheet
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Revision 2.0, 2014-08-26