LTC6102CDD(RevB) View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC6102CDD Datasheet PDF : 20 Pages
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LTC6102/LTC6102HV
APPLICATIONS INFORMATION
VBAT
RSENSE
RIN
+IN
+–
LOAD
V–
–INS
–INF
V+
VREG
0.1μF
LTC6102
OUT
VOUT
ROUT
6102 F06
Figure 6. LTC6102 Supply Current Monitored with Load
Because the voltage across RSENSE is not restricted to
the sense range of the LTC6102 in this circuit, VSENSE
can be large compared to the allowed sense voltage. This
facilitates the sensing of very large voltages, provided
that RIN is chosen so that VSENSE/RIN does not exceed
the allowed output current. The gain is still controlled by
ROUT/RIN, so either gain or attenuation may be applied to
the input signal as it is translated to the output. Finally,
the input may be a voltage source rather than a sense
resistor, as shown in Figure 7. This circuit allows the
translation of a wide variety of input signals across the
entire supply range of the LTC6102 with only a tiny offset
error while retaining simple gain control set by ROUT/RIN.
V+
VIN
RIN
+IN
VCM
+–
V–
–INS
–INF
V+
VREG
0.1μF
LTC6102
OUT
VOUT
ROUT
VOUT
=
VIN
•
ROUT
RIN
6102 F07
Figure 7. Voltage Level-Shift Circuit
14
Again, very large voltages may be sensed as long as RIN
is chosen so that IOUT does not exceed the allowed output
current. For example, VIN may be as large as 1V with RIN =
1k, or as large as 10V with RIN = 10k. For a 10V maximum
input and a 5V maximum output, RIN = 10k and ROUT = 5k
will allow the LTC6102HV to translate VIN to VOUT with a
common mode voltage of up to 100V. For the case where
a large input resistor is used, a similar resistor in series
with +IN will reduce error due to input bias current.
Reverse Supply Current
Some applications may be tested with reverse-polarity
supplies due to an expectation of this type of fault during
operation. The LTC6102 is not protected internally from
external reversal of supply polarity. To prevent damage
that may occur during this condition, a Schottky diode
should be added in series with V– (Figure 8). This will
limit the reverse current through the LTC6102. Note that
this diode will limit the low voltage performance of the
LTC6102 by effectively reducing the supply voltage to the
part by VD.
RSENSE
R1
+IN
–INS 100
L
O
V–
A
D
–INF
V+
VREG 0.1μF
VBATT
LTC6102
D1
OUT
R2
4.99k
6102 F08
Figure 8. Schottky Prevents Damage During Supply Reversal
In addition, if the output of the LTC6102 is wired to a device
that will effectively short it to high voltage (such as through
an ESD protection clamp) during a reverse supply condi-
tion, the LTC6102’s output should be connected through
a resistor or Schottky diode (Figure 9).
6102fb
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