ISL70100SEH, ISL73100SEH

5. Applications Information

R34DS0009EU0101 Rev.1.01

Page 22 of 27

Jul.10.20

5.5

Response Time

The ISL7x100SEH is designed to provide fast response time for circuit protection or signal transmission. The

delay and speed of the response depend on the starting point of the step. If the sensed current is very low (near

zero) before the transient, there may be an increased delay time to see the output react. If fast reaction times are

required, increase the sense resistance such that there are a few millivolts (1-5mV) of differential across the

inputs under the lowest current condition. The higher the differential is for the lowest current condition, the faster

the response time is, but that results in increased DC power losses.

Figures 43 and 44 show the step response difference from starting with a 0mV differential versus starting with a

25mV differential. For most applications the 40-50ns faster reaction time may not warrant the resulting power

loss.

Figure 43. 0mV to 150mV Step Response

Figure 44. 25mV to 150mV Step Response

0

200

400

600

800

1000

1200

1400

1600

-500

-400

-300

-200

-100

0

100

200

300

25

30

35

40

Time (µs)

0.1V/div

0.2mA/div

0.2mA/div

0.2mA/div

VSEN

IOUT (125°C)

IOUT (25°C)

IOUT (-55°C)

t

RES = 295.6 ns

t

RES = 254.4ns

t

RES = 254.9ns

V+ = 12V

0

200

400

600

800

1000

1200

1400

1600

-500

-400

-300

-200

-100

0

100

200

300

25

30

35

40

Time (µs)

0.1V/div

t

RES = 217.8ns

t

RES = 206.0ns

t

RES = 258.4ns

VSEN

IOUT (125°C)

IOUT (25°C)

IOUT (-55°C)

0.2mA/div

0.2mA/div

0.2mA/div

V+ = 12V