TLE4254
Application Information
Data Sheet 16 Rev. 1.2, 2009-11-18
Figure 6 Application circuit: Output voltage
V
Q
lower than reference voltage V
REF
Status Output feedbacked to microcontroller (version GS / EJ S)
In order to obtain a lower output voltage
V
Q
at the tracker output than the reference voltage V
REF
, a voltage divider
according to Application circuit: Output voltage VQ lower than reference voltage VREF Status Output
feedbacked to microcontroller (version GS / EJ S) has to be used. The output voltage
V
Q
then calculates:
With a given reference voltage
V
REF
, the desired output voltage V
Q
and the resistor value R1
ADJ
, the resistor value
for
R2
ADJ
is given by:
Taking into consideration also the effect of the internal EN/ADJ pull-down resistor, the external resistor divider’s
R2
ADJ
has to be selected to:
EN/
ADJ
IQ
GND
TLE4254GS
TLE4254EJ S
8
5
1
micro controller
e.g.
C167,
XC16X
TC17xx
VDD
I/O
Main µC supply
e.g.
TLE4271-2
TLE4471
TLE6368...
IQ
GND
VBAT
VQ < VREF
R1
ADJ
R2
ADJ
VREF
ST
4
2, 3, 6, 7
I/O
V
Q
V
REF
R2
ADJ
R1
ADJ
R2
ADJ
+
--------------------------------------- -
⋅=
R2
ADJ
R1
ADJ
V
Q
V
REF
V
Q
–
---------------------------
⋅=
R2
ADJ select,
R2
ADJ
R
PullDown min,
⋅
R
PullDown min,
R2
ADJ
–
--------------------------------------------------------- -
=
