tDELAY

VS

OUT

IN+

IN-

Power Supply

0 V to 36 V

2.7 V to 5.5 V

+

Load

ALERT2

LIMIT2

GND

ALERT1

LIMIT1

Supply

CDELAY

DELAY

Supply

LATCH1

LATCH2

REF

INA303

RLIMIT1

RLIMIT2

RPULL-UP1

Undercurrent

Threshold

Overcurrent

Threshold

RPULL-UP2

Input Signal

VOUT

ALERT1

ALERT2

RSENSE

VLIMIT1

VLIMIT2

17

INA302, INA303

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SBOS775C – SEPTEMBER 2016 – REVISED MARCH 2019

Product Folder Links: INA302 INA303

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Copyright © 2016–2019, Texas Instruments Incorporated

Feature Description (continued)

Figure 43 shows the alert output response of the internal comparators for the INA303. Both ALERTx outputs are

in the default high state when the output voltage of the current-sense amplifier is less than the voltage developed

at the LIMIT1 pin and is greater than the voltage developed at the LIMIT2 pin. The ALERT1 output becomes

active and pulls low when the current-sense amplifier output voltage exceeds the threshold voltage set at the

LIMIT1 pin. The low voltage on ALERT1 indicates that the measured signal at the amplifier input has exceeded

the programmed threshold level, indicating an overcurrent or out-of-range condition has occurred. When the

current-sense amplifier output is less than the threshold voltage set by the LIMIT2 pin, the ALERT2 output pulls

low after the delay time set by the external delay capacitor expires. The delay time for the ALERT2 output is

proportional to the value of the external CDELAY capacitor, and is calculated by Equation 2.

Figure 43. Out-of-Range Alert Responses for the INA303