LTC2052 LINER [Linear Technology], LTC2052 Datasheet - Page 15

• Manufacturer Part Number: LTC2052
• Description: High Voltage, High-Side Current Sense
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
Reverse Supply Protection
Some applications may be tested with reverse-polarity
supplies due to an expectation of this type of fault during
operation. The LTC6101 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
reverse current through the LTC6101. Note that this diode
will limit the low voltage performance of the LTC6101 by
effectively reducing the supply voltage to the part by V
In addition, if the output of the LTC6101 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 LTC6101’s output should be connected through
a resistor or Schottky diode (Figure 8).
Response Time
The LTC6101 is designed to exhibit fast response to inputs
for the purpose of circuit protection or signal transmission.
This response time will be affected by the external circuit
in two ways, delay and speed.
Figure 7. Schottky Prevents Damage During Supply Reversal
O
D
L
A
+IN
V
D1
–
LTC6101
+
R
SENSE
–
–
(Figure 7). This will limit the
–IN
OUT
V
+
R1
100
R2
4.99k
6101 F07
V
BATT
D
.
If the output current is very low and an input transient
occurs, there may be an increased delay before the output
voltage begins changing. This can be improved by increas-
ing the minimum output current, either by increasing
R
current is illustrated in the step response curves in the
Typical Performance Characteristics section of this data
sheet. Note that the curves are labeled with respect to the
initial output currents.
The speed is also affected by the external circuit. In this
case, if the input changes very quickly, the internal ampli-
fi er will slew the gate of the internal output FET (Figure
1) in order to maintain the internal loop. This results in
current fl owing through R
current slew rate will be determined by the amplifi er and
FET characteristics as well as the input resistor, R
ing a smaller R
more quickly, decreasing the response time at the output.
This will also have the effect of increasing the maximum
output current. Using a larger R
sponse time, since V
increasing R
voltage gain of the circuit.
SENSE
O
D
L
A
+IN
or decreasing R
V
–
Figure 8. Additional Resistor R3 Protects
Output During Supply Reversal
D1
LTC6101
OUT
IN
+
LTC6101/LTC6101HV
will both have the effect of increasing the
R
will allow the output current to increase
SENSE
–
OUT
IN
= I
. The effect of increased output
–IN
V
OUT
IN
OUT
+
and the internal FET. This
• R
R1
100
OUT
R2
4.99k
R3
OUT
1k
will decrease the re-
. Reducing R
V
BATT
ADC
15
6101 F08
IN
IN
. Us-
6101fh
and