The wide dynamic input range of the INA300 INA300 necessitates an adjustable hysteresis to ensure that the

device can be appropriately configured based on the specific operating conditions and application requirements.

Figure 7-7 illustrates the transition locations for the ALERT terminal based on where the input signal, VIN, is

measured relative the limit threshold, VLIMIT. The corresponding hysteresis levels and physical terminal settings

for the device are shown in Table 7-5.

VLIMIT

VLIMIT - Hysteresis

Alert

Output

VOUT

VIN

Figure 7-7. Typical Comparator Hysteresis

Table 7-5. Hysteresis Settings

HYSTERESIS

HYSTERESIS SETTING

Float

2 mV

GND

4 mV

VS

8 mV

7.3.6 Alert Output

The device ALERT terminal is an active-low, open-drain output. This output is designed to be pulled low when

the input conditions are detected as out-of-range. This open-drain output pin is recommended to include a

10-kΩ, pull-up resistor to the supply voltage. This open-drain terminal can be pulled up to a voltage beyond the

supply voltage, VS, but must not exceed 5.5 V.

7.3.7 Noise Adjustment Factor (NAF)

The device is a high-speed, low-noise comparator that is designed to alert when the measured input signal

exceeds the programmed limit level. Internal noise in the device couples into the measurement and can result

in alerts being issued prior to the input signal exceeding the voltage level present at the LIMIT terminal. This

known internal noise component effects the input signal measurement by causing a consistent shift in the device

internal offset, resulting in a shifted trip threshold. NAF adjusts the VLIMIT setting to account for this internal shift,

thus allowing for a more precise level detection of the measured current.

The NAF value is based on the noise contribution on the measurement at the 10-µs delay setting. This value is

equal to 500 µV and is applied in the calculation to adjust the VLIMIT threshold level to allow for a more accurate

alert trip point. The NAF term is only applied in the VLIMIT calculation at the 10-µs delay setting. The averaging

effect included with the 50-µs and 100-µs delay settings inherently eliminates the effect internal noise has on the

threshold voltage. The NAF term can be omitted from the RLIMIT calculation at the 10-µs delay setting with the

effect of a lower trigger point of the alert output. Lowering the trigger point results in an overcurrent alert prior to

reaching the corresponding VTRIP threshold.

www.ti.com

INA300

SBOS613C – FEBRUARY 2014 – REVISED JUNE 2021

Copyright © 2021 Texas Instruments Incorporated

Submit Document Feedback

17

Product Folder Links: INA300