TLE9263QX
External Voltage Regulator 3
8.4
Calculation of RSHUNT
As a independent regulator, the maximum current ICC3max where the limit starts and the bit ICC3 > ICC3max is set is
determined by the shunt resistor RSHUNT and the Output Current Shunt Voltage Threshold Vshunt_threshold
.
The resistor can be calculated as following:
Ushunt _ threshold
RSHUNT
=
(1)
ICC3 max
If VCC3 is configured for load sharing, then the shunt resistor determines the load sharing ratio between VCC1
and VCC3. The ratio can be calculated as following:
I CC
I CC
110 Ω 105 − 15 mV
I CC
1
3
1
=
( a )
(2)
R
SHUNT
I CC ⋅ 110 Ω 105 − 15 mV
1
I CC
=
( b )
3
R
SHUNT
Example: A shunt resistor with 470mꢀ and a load current of 100mA out of VCC1 would result in ICC3 = 191mA.
8.5
Unused Pins
In case the VCC3 is not used in the application, it is recommended to connect the unused pins of VCC3 as
followed:
•
•
•
•
Connect VCC3SH to VS or leave open;
Leave VCC3B open;
Leave VCC3REF open
Do not enable the VCC3 via SPI as this leads to increased current consumption
Data Sheet
53
Rev. 1.1, 2014-09-26
INFINEON [ Infineon ]
