3
dc2033af
DEMO MANUAL DC2033A
Quick start setup
Figure 4. DC2033A Quick Setup Circuit and Equations
Setting Up the DC2033A for Wire Compensation
Testing
The DC2033A default circuit uses the LT6110 internal
20mΩ sense resistor (R
SENSE
) and is configured with
0Ω RJ1, RJ2 and RJ3 are installed with 0Ω jumpers.
The RJ1 and RJ2 are standard 0Ω jumpers and con-
nect the LT6110 amplifier across the internal R
SENSE
.
The RJ1 and RJ2 resistance is not a concern as the
current flowing through them is very small (the resis-
tance variation of standard 0Ω resistors is 20mΩ to
100mΩ). However, a standard 0Ω jumper must not be
used in the path of the load current because the jumper's
I
•
R drop adds an error term to a wire drop compensation
design (for example the I
•
R drop of a 50mΩ jumper for
2A is 100mV). The RJ3 jumper is ultra-0Ω, with less than
1mΩ and rated for 30A at 70°C. The RJ3 jumper can be
removed and re-installed as RJ6 or RJ9, to configure the
DC2033A with an LT6110 and an external R
SENSE
(for an
alternative to an ultra-0Ω jumper install two 0.25 inch
length of 18AWG solid copper wires in parallel for up to
20A I
LOAD
).
The R
IN1
resistor and the V
SENSE
voltage set the LT6110
output current (I
IOUT
) for regulator output voltage control.
The I
IOUT
current connects to the regulator feedback resis-
tors and boosts the regulator's output voltage (V
REG
). The
V
REG
voltage increases directly with the load current and
cancels the wire's I
•
R drop (V
DROP
) to the remote load.
A DC2033A has 0805 size pads for installing a switching
regulator's feedback resistors (R
FA
, R
FB
and R
G
). A low
quiescent current switching regulator has 10µA or less
current flowing through the feedback divider and requires
I
OUT
+IN
–IN
R
IN1
402Ω
RJ10
0Ω
R
OUT
100Ω
R1
1k
RJ1
0Ω
RJ2
0Ω
E4
GND
E2
5Ω LOAD
C2
0.1µF
LT6110
V
+
V
–
RS
I
MON
+
–
GND
E3
E1 TO E5
WIRE JUMPER
REGULATOR
E1
I
LOAD
1A
I
LOAD
1A
RJ3
0Ω
DC2033 F04
R
SENSE
5V POWER
SUPPLY
I
IOUT
E6
V
OUT2
E7
IMON
E5
V
OUT1
RMON
100Ω
EB
3× I
IOUT
I
IOUT
=
V
OUT1
−
V
OUT2
R
OUT
I
IOUT
=
I
LOAD
•
R
SENSE
+
V
OS
R
IN1
R
OUT
=
100
R
IN1
=
402
TYPICAL V
OS
=
100µV
R
SENSE
=
20mΩ,
±
15%
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