Datasheet

LTC6430-15
10
643015f
operaTion
The LTC6430-15 is a highly linear, fixed-gain amplifier
for differential signals. It can be considered a pair of 50Ω
single-ended devices operating 180 degrees apart. Its core
signal path consists of a single amplifier stage minimiz-
ing stability issues. The input is a Darlington pair for high
input impedance and high current gain. Additional circuit
enhancements increase the output impedance commen-
surate with the input impedance and minimize the effects
of internal Miller capacitance.
The LTC6430-15 uses a classic RF gain block topology,
with enhancements to achieve excellent linearity. Shunt
and series feedback elements are added to lower the input/
output impedance and match them simultaneously to the
source and load. An internal bias controller optimizes the
bias point for peak linearity over environmental changes.
This circuit architecture provides low noise, good RF power
handling capability and wide bandwidth; characteristics
that are desirable for IF signal-chain applications.
Figure 1. Test Circuit A
TesT circuiT a
643015 F01
V
CC
= 5V
T1
1:2
PORT
INPUT
RF
OUT
50Ω, SMA
RF
IN
50Ω, SMA
PORT
OUTPUT
BALUN_A
BALUN_A
BALUN_A = ADT2-IT FOR 50MHz TO 300MHz
BALUN_A = ADT2-1P FOR 300MHz TO 400MHz
BALUN_A = ADTL2-18 FOR 400MHz TO 1000MHz
ALL ARE MINI-CIRCUITS CD542 FOOTPRINT
C1
1000pF
L1
560nH
LTC6430-15
DNC
DNC
DNC
DNC
DNC
DNC
+OUT
GND
T_DIODE
DNC
GND
–OUT
+IN
GND
V
CC
DNC DNC DNC
–IN GND V
CC
DNC DNC DNC
••
C2
1000pF
C4
1000pF
C3
1000pF
C7
60pF
C5
1nF
R1
350Ω
C6
0.1µF
C8
60pF
R2
350Ω
L2
560nH
T2
2:1
Differential Application Test Circuit A (Balanced Amp)