TLE4254 Datasheet, PDF (17/21 Pages) Infineon Technologies AG – High Accuracy Low Dropout Voltage Tracking Regulator

TLE4254
Application Information
VBAT
Main µC supply
I
e.g.
Q
TLE4271-2
TLE4471
TLE6368...
GND
VREF
micro controller
e.g.
VDD
C167,
XC16X
TC17xx
I/O
EN/
5 ADJ
1
Q
TLE4254GA
TLE4254EJ A
I
8
4
FB
GND
2, 3, 6, 7
R1_FB
R2_FB
VQ > VREF
Figure 7 Application circuit: Output voltage V_Q higher than reference voltage V_REF (version GA / EJ A
only)
For output voltages higher than the reference voltage, the voltage divider has to be applied between the feedback
and the output according to Application circuit: Output voltage VQ higher than reference voltage VREF
(version GA / EJ A only). 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
17
Rev. 1.2, 2009-11-18