TLE4253 Datasheet, PDF (18/22 Pages) Infineon Technologies AG – Low Dropout Voltage Tracking Regulator

TLE4253
Application Information
VBAT
Main µC supply, e.g.
I TLE4271-2 Q
TLE4278
TLE4470
etc.
GND
VREF
µC, e.g. C167
VDD
I/O
EN/
5 ADJ
1
Q
TLE 4253 G
I
8
GND
2, 3, 6, 7
4
FB
R1_FB
R2_FB
VQ > VREF
Figure 5 Application circuit: Output voltage V_Q higher than reference voltage V_REF
For output voltages higher than the reference voltage, the voltage divider has to be applied between the feedback
and the output according to Figure 5. The equation for the output voltage with respect to the reference voltage is
given by:
V_Q
=
V_R
EF
⋅


R-----1---_F---RB----2-+_{--F---RB----2---F---B--}
Keep in mind that the input voltage has to be at minimum equal to the output voltage plus the dropout voltage of
the regulator.
With a given reference voltage V_REF, the desired output voltage V_Q and the resistor value R1_FB, the resistor value
for R2_FB is given by:
R2_FB
=
R1_FB
⋅


V-----_Q^--V---–^{--R--V--E---FR---}_E^----_F^{-}
Data Sheet
18
Rev. 1.2, 2009-11-09