DEMO CIRCUIT 1 1 1 3
LTC6102
Q UICK S TA RT G UIDE
L TC6 1 0 2
P re c is io n Z e ro Drift Cu rre n t S e n s e A m p lifie r
DESCRIPTION
Demonstration circuit 1113 is a General Purpose High-
Side Current-Sense Ampl ier f
if eaturing the LTC6102.
This demo board ampl ies an on-board current-sense
if
resistor vol
tage-drop, providing a precision uni-pol
ar
output vol
tage proportional to l
oad current. The demo
circuit incl
udes scal resistors that program the gain of
ing
the circuit to 33. V. The LTC6102 is pow ered f
3V/
rom the
y
same suppl that the sense resistor is connected to and
provides a ground ref
erenced output. The LTC6102 can
perf
orm current measurements on suppl ranging f
ies
rom
tage is devel
oped as a
4V to 60V. Since the output vol
controled current through a l
l
oad resistance, ground-
l errors can be el
oop
iminated by simpl l
y ocating the l
oad
resistor at the destination point (subsequent signal proc-
essing such as A/ conversion). Remote l
D
oading can be
eval
uated by simpl removing the on board l resistor
y
oad
(R3).
The key perf
ormance characteristics of the LTC6102 and
DC1113 are show n in the Perf
ormance Summary bel .
ow
Design files for this circuit board are available. Call
the LTC factory.
L
, LT are registered trademarks ofLinear Technol Corporation.Other product names
ogy
may be trademarks ofthe companies that manuf
acture the products.
PERF ORM ANCE SU M M ARY
SYM BOL
V
IN
V
M ON
I
M ON
I
OUT
I
INQ
t
R
PARAM ETER
M onitored Suppl Input Range
y
M easurement Output Signal
M easurement Output Signal(current mode)
Output Load Current Range
V
IN
Quiescent Current
V
M ON
step-response time
Specifications are at T
A
= 25°C
CONDI ONS
TI
I
OUT
= 10A
I
OUT
=10A, R3 removed
Thermall ofR
SENSE
imit
V
IN
=12V, I
OUT
= 0A
I
OUT
step f
rom 0A to 10A
MI
N
4
TYP
5… 48
2.
0
400
230
4
M AX
60
UNI
TS
V
V
µA
A
µA
µs
12
OPERATING PRINCIPL ES
The LTC6102 operates by ampl ying the vol
if
tage drop on
a sense resistor pl
aced in series w ith the pow er source of
a l to be monitored. The sense inputs of the ampl ier
oad
if
dif erentialy measure the sense-resistor drop to control
f
l
an internal variabl current source that alow s transl
e
l
ation
of the input inf
ormation to a l
evel ref
erenced to V–
(ground in this demo circuit). The circuit gain is estab-
l
ished by the ratio of the output resistor to the input re-
sistor and is essentialy as accurate as the resistors used.
l
In DC1113 as shipped, the sense resistor instaled is
l
6mΩ and the resistor ratio sets the gain to 33. V, so
3V/
the nominal output scal is 200mV per Ampere of l
ing
oad
current. Other scal can be produced by resistor re-
ing
pl
acement on the demo circuit.
The DC1113 Schematic diagram is show n in Figure 2.
1
LTC6102
Q U ICK START PROCEDU RE
Demonstration circuit 1113 is easy to set up to eval
uate
the perf
ormance of the LTC6102. Ref to Figure 1 f
er
or
proper measurement equipment setup and f l the
olow
procedure bel :
ow
1.
W ith pow er of , connect the pow er suppl positive to
f
y
IN and the common to GND. This suppl shoul be in
y
d
the range of 4V to 60V. If this suppl is not equipped
y
w ith an accurate current readout, a DM M (set to
measure Amperes) may be connected in series w ith
the suppl as show n in Figure 1.
y
NOTE.
Be sure that the current capacity ofthe DM M is adequate to
handl the intended l current.
e
oad
2.
Connect a vol
tmeter or osciloscope probe to the M ON
l
terminal w ith the common connection or ground cl
,
ip
tied to GND.
3.
Connect a l to the OUT terminal (positive) and re-
oad
turn (negative) to the common of the pow er suppl
y.
The l may be a pow er resistor, active l instru-
oad
oad
ment, or other circuit ofinterest.
4.
Turn on the pow er suppl
y.
5.
M easure an output vol
tage that corresponds to the
l current. V
M ON
= 0.
OUT
f the f
oad
2×I
or
actory instaled
l
resistors.
POWER
SUPPLY
1.0
00
+ COM
100
.0
DMM
A COM V
020
.0
DMM
A COM V
LOAD
(10Ω)
Figure 1. Proper M easurem ent Equipm ent Setup
2
Analogue and Mixed Signal
京公网安备 11010802033920号
EEWORLD
