AD8392ARE Analog Devices Inc, AD8392ARE Datasheet - Page 11

• Manufacturer Part Number: AD8392ARE
• Description: IC LINE DRVR ADSL/ADSL2 28TSSOP
• Manufacturer: Analog Devices Inc
• Type: Driverr

Specifications of AD8392ARE

• Number Of Drivers/receivers: 2/0
• Protocol: xDSL
• Voltage - Supply: 5 V ~ 24 V
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP Exposed Pad, 28-eTSSOP, 28-HTSSOP
• Power Supply Requirement: Single/Dual
• Package Type: TSSOP EP
• Slew Rate: 900V/us
• Pin Count: 28
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

THEORY OF OPERATION
The AD8392 is a current feedback amplifier with high
(400 mA) output current capability. With a current feedback
amplifier, the current into the inverting input is the feedback
signal, and the open-loop behavior is that of a transimpedance,
dV
The open-loop transimpedance is analogous to the open-loop
voltage gain of a voltage feedback amplifier. Figure 33 shows a
simplified model of a current feedback amplifier. Since R
proportional to 1/g
where g
analysis of the follower with gain circuit yields
where:
Since G × R
has relatively constant bandwidth versus gain, the 3 dB point
being set when |T
O
/dI
G
R
V
V
IN
IN
IN
O
= 1
m
or T
=
is the transconductance of the input stage. Basic
=
+
G
g
1
IN
R
R
m
Z
×
G
F
.
<< R
≈
T
Z
50
Z
( )
| = R
m
S
F
Ω
, the equivalent voltage gain is just T
for low gains, a current feedback amplifier
+
T
F
G
.
Z
×
( )
S
R
IN
+
R
F
Z
IN
× g
is
Rev. A | Page 11 of 16
m
,
Of course, for a real amplifier there are additional poles that
contribute excess phase, and there is a value for R
the amplifier is unstable. Tolerance for peaking and desired
flatness determines the optimum R
The AD8392 is capable of delivering 400 mA of output current
while swinging to within 2 V of either power supply rail. The
AD8392 also has a power management system included on-chip.
It features four user-programmable power levels (three active
power modes as well as the provision for complete shutdown).
V
IN
R
R
G
N
Figure 33. Simplified Block Diagram
R
I
IN
IN
R
T
F
Z
F
in each application.
F
V
OUT
below which
AD8392