AUIPS7142G
Over-current protection
The threshold of the over-current protection is set in order to guaranteed that the device is able to turn on a load with an
inrush current lower than the minimum of Isd. Nevertheless for high current and high temperature the device may switch
off for a lower current due to the over-temperature protection. This behavior is shown in Figure 11.
Current sensing accuracy
Iout
Ifb
Ifb leakage
Ifb2
Ifb1
Iout2 Iout1 I offset
The current sensing is specified by measuring 3 points :
- Ifb1 for Iout1
- Ifb2 for Iout2
- Ifb leakage for Iout=0
The parameters in the datasheet are computed with the following formula :
Ratio = ( Iout2 – Iout1 )/( Ifb2 – Ifb1)
I offset = Ifb1 x Ratio – Iout1
This allows the designer to evaluate the Ifb for any Iout value using :
Ifb = ( Iout + I offset ) / Ratio if Ifb > Ifb leakage
For some applications, a calibration is required. In that case, the accuracy of the system will depends on the variation of
the I offset and the ratio over the temperature range. The ratio variation is given by Ratio_TC specified in page 4.
The Ioffset variation depends directly on the Rdson :
I offset@-40°C= I offset@25°C / 0.8
I offset@150°C= I offset@25°C / 1.9
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