AUIPS7141R Datasheet, PDF (7/13 Pages) International Rectifier – CURRENT SENSE HIGH SIDE SWITCH

Current sensing accuracy
Ifb
Ifb2
AUIPS7141R
Ifb1
Ifb leakage
I offset
Iout1
Iout2
Iout
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
Maximum Vcc voltage with short circuit protection
The maximum Vcc voltage with short circuit is the maximum voltage for which the part is able to protect itself under test
conditions representative of the application. 2 kind of short circuits are considered : terminal and load short circuit.
L supply R supply
5µH 10mohm
Vcc
IPS ^Out
L SC
R SC
Terminal SC
Load SC
L SC
0.1 µH
10 µH
R SC
10 mohm
100 mohm
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