LTC6101HV Linear Technology, LTC6101HV Datasheet - Page 14

• Manufacturer Part Number: LTC6101HV
• Description: High-Side Current Sense Amplifier
• Manufacturer: Linear Technology

LTC6101/LTC6101HV
APPLICATIONS INFORMATION
Reverse Supply Protection
Some applications may be tested with reverse-polarity
supplies due to an expectation of the 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
limit the 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.
14
Figure 7. Schottky Prevents Damage During Supply Reversal
O
D
L
A
D
.
+IN
V
D1
–
LTC6101
+
R
SENSE
–
–IN
OUT
V
+
–
(Figure 7). This will
R1
100
R2
4.99k
6101 F07
V
BATT
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 increasing the minimum output current, either by in-
creasing R
output current is illustrated in the step response curves
in the Typical Performance Characteristics section of this
datasheet. 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.
O
D
L
A
+IN
V
–
Figure 8. Additional Resistor R3 Protects
Output During Supply Reversal
D1
SENSE
LTC6101
OUT
IN
+
or decreasing R
will both have the effect of increasing the
R
will allow the output current to increase
SENSE
–
OUT
= I
–IN
V
OUT
IN
OUT
+
and the internal FET. This
R1
100
• R
IN
OUT
R2
4.99k
. The effect of increased
R3
1k
OUT
will decrease the re-
. Reducing R
V
BATT
ADC
6101 F08
IN
IN
. Us-
6101fg
and