Data Sheet 10 Rev. 1.1, 2007-09-21
TLE 4276-2
Application Information for Variable Output Regulator TLE 4276-2 DV, GV
The output voltage of the TLE 4276-2 DV, GV can be adjusted between 2.5 V and 20 V
by an external output voltage divider, closing the control loop to the voltage adjust pin
VA.
The voltage at pin VA is compared to the internal reference of typical 2.5 V in an error
amplifier. It controls the output voltage.
Figure 5 Application Detail External Components at Output for Variable
Voltage Regulator
The output voltage is calculated according to Equation (1):
V
Q
= (R
1
+ R
2
)/R
2
× V
ref
, neglecting I
VA
(1)
V
ref
is typically 2.5 V.
To avoid errors caused by leakage current
I
VA
, we recommend to choose the resistor
value R
2
according to Equation (2):
R
2
< 50 kΩ (2)
For a 2.5 V output voltage the output pin Q is directly connected to the adjust pin VA.
The accuracy of the resistors
R
1
and R
2
add an additional error to the output voltage
tolerance.
The operation range of the variable TLE 4276-2 DV, GV is V
Q
+ 0.5 V to 40 V. For
internal biasing a minimum input voltage of 4.3 V is required. For output voltages below
4 V the voltage drop is 4.3 V - V
Q
AEB02804
Current
and
Saturation
Control
Internal
Reference
2.5 V Typical
5
V
ref
R
2
R
1
C
Q
22 µF
Q
VA
4
