TAT8857 View Datasheet(PDF) - TriQuint Semiconductor
Part Name
Description
MFG CO.
'TAT8857' PDF : 8 Pages View PDF
TAT8857
CATV Doubler – Hybrid RFIC
Detailed Device Description
The TAT8857 is similar to other parts offered on the market; it contains two separate amplifiers. A major difference is the
TAT8857 allows much flexibility to set gain and bias to cover multiple applications without an additional stage. This makes it
ideal for green designs. It uses a cost effective high voltage MESFET technology (designed for CATV) and a pHEMT process
(developed for high-volume applications). On-chip linearization is also utilized.
Bias Current Adjustment
R7 180 L9 82nH C9 82pF
+24v
GND
Bias current is determined by 2 settings:
C3
MABACT0051 .01uF
1. Size of DC feedback resistors - decreasing
3
R1 & R2 will increase IDD
2
4
2
2. Tail resistors - decreasing R21 will
1
1
3
increase IDD, but lead to wider variationsRF T1
IN
C4
Active biasing schemes are possible but not
.01uF
necessary for most applications.
Best performance is with IDD = 350mA
R3
C7 .01uF
390
R1 27k
R9 100 C11 0.01u
L5
15nH
C27 0.7pF
1
R5 8.09k2
C5
1.8pF
C6
1.8pF
R21 5.1
5.1
3
L7 600
4
1
2
5
1
2
L8 600 6
R6 8.09k 7
L6
15nH
8
C28 0.7pF
LIN ADJ A
16
BIAS 2A
UPPER A
15
14
LOWER A
U1
BIAS 1A
13
GATE A
TAT888587D 57F3
12
BIAS 1B
GATE B
LOWER B
11
LIN ADJ B
10
UPPER B
9
BIAS 2B
R2 27k
R4
390
C8 .01uF
R10 100 C12 0.01u
C13 0.01uF
C15
L11
470nH
R20
33
L13
R13
27nH
1.3k
R11 18
R12 18
L19 600
1
2
Vga
L14
R14
27nH
1.3k
L12
R21
470nH
33
C14 0.01uF
2.2pF
C16
R8 180 L10 82nH C10 82pF
Voltage Biasing: 24V and 12V
The TAT8857 has two amplifiers which can be configured to split a 24 V supply (and share the same current) or both
amplifiers can be biased from a 12V supply and draw current independently.
Data Sheet: Rev C 06-05-12
© 2012 TriQuint Semiconductor, Inc.
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Disclaimer: Subject to change without notice
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