TAT2814A1L(2014) View Datasheet(PDF) - TriQuint Semiconductor
Part Name
Description
Manufacturer
TAT2814A1L Datasheet PDF : 12 Pages
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TAT2814A1L
DOCSIS 3.0 / Edge QAM Variable Gain Amplifier
Detailed Device Description
Balance
The TAT2814A1L is designed for excellent differential-mode performance throughout the chain. Unlike many
commercially available push-pull amplifiers built with 2 discrete die, both stages of the TAT2814A1L are single-chip
designs utilizing a differential pair topology for best common-mode performance. Provision is made for using external
bias inductors to increase tail impedances in the input differential pairs, improving further the signal balance and 2nd
order performance through the chain. The RF output of the first stage is connected internally to the differential
attenuator and brought out to external pins for applying stage bias and enabling RF feedback to the input. The
attenuator outputs are brought out to a single side of the TAT2814A1L for customers desiring to perform inter-stage
filtering or signal processing. The differential inputs to the output stage are located on an adjacent side of the die,
spaced to minimize package coupling so as to not limit the performance of off-stage filtering.
Input Matching
The input stage uses external feedback to achieve 75 Ω differential input impedance. The bias current of the input
stage may be adjusted with an external resistor to ground.
Pre-Amp Powerdown
The preamp stage of the TAT2814A1L can be powered down by setting PD pin to Logic LOW. VDD pins should be set
to 5 V in both power-down and operating modes.
Gain Adjustment
A fully differential gain control function is implemented with a low distortion analog diode-based attenuator. The
attenuator provides for monotonic gain adjustment over a full 18 dB attenuation range. The excellent RF match
characteristics ensure excellent gain flatness and return loss over the full attenuation range. Control is provided by a
single current controlled line. Attenuation is monotonic and linear with control current.
Output Stage
A differential output stage has excellent output linearity performance at very low power. The differential outputs of the
second stage may be combined with a commercially available balun to provide for single-ended drive signals. The
bias current of the output stage may be placed in active bias control. This is implemented by sensing the voltage at pin
19 and providing a feedback voltage bias to pin 27. Please contact TriQuint for further details.
Thermal Management
Total maximum power consumption of the TAT2814A1L is 5.25 Watts. Care must be taken in the layout to provide
adequate thermal path with multiple vias under the TAT2814A1L. A heat sink should also be used to carry heat away
from the backside PCB. See section on Mechanical Information for recommended mounting pattern for the part.
Technology
The TAT2814A1L utilizes proven pHEMT device technology that has yielded over 200 million RFICs to date. For
detailed qualification and reliability reports on other products fabricated in this process, please consult TriQuint. Key
RFICs that will be used in the TAT2814A1L have already exceeded industry qualification requirements in other
packages.
Bias Current Set
Bias current to each amplification stage is set by external circuitry to allow trade-off of power consumption and
distortion performance.
Separate Bias Voltage for each stage
Preamplifier, interstage attenuator, and driver amplifier have independent voltage supply pins.
Datasheet: Rev. H 11-12-14
© 2014 TriQuint
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Disclaimer: Subject to change without notice
www.triquint.com
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