TLF51801ELV Datasheet, PDF (13/29 Pages) Infineon Technologies AG – 10 A synchronous DC/DC Step-Down Controller

TLF51801ELV
Regulator
5.5.2 Shunt-configuration
The regulator is offering a second possibility to do a more accurate current measurement by shunt resistor located
in series with the drain of the high-side MOSFET. The shunt resistor will be placed in the input current path and
be connected to the overcurrent comparator with pin senselow and through a sense resistor to pin sensehigh. By
varying the sense resistor the current limit can be adjusted.
P ow er current
flo w
E xternal high side M O S
VS
BUO
R_SHUNT
R_SENSE
SEN S EH IG H
SENSELOW
OVERCURRENT
COMPARATOR
(O VC )
BLANK
OVERCURRENT
LO G IC SIG N A L
Figure 9 Shunt-configuration for current limitation
The Shunt-configuration works similar to the Rdson-configuration, it uses also pins Sensehigh and Senselow. The
current limitation might be calculated with the following equation:
I _limit
= I _{OC _ lim, ref}
⋅ ^{R _ SENSE}
R _ SHUNT
Data sheet
13
Rev. 1.0.1, 2013-04-15