Datasheet

Application information SEA05L
6/12 Doc ID 18462 Rev 1
2 Application information
Figure 3. Typical application schematic
2.1 Voltage and current control
Voltage control
The voltage loop is controlled via a transconductance operational amplifier, the voltage
divider R
1
, R
2
, and the optocoupler which is directly connected to the output. It is possible to
choose the values of R
1
and R
2
resistors using Equation 1 and Equation 2:
Equation 1
Equation 2
where V
O
is the desired output voltage.
As an example, with R
1
= 100 kΩ and R
2
= 15 kΩ V
O
= 19.17 V.
Vo
Io
R1
R2
0.1μF
Rsense
V
R
RR
V
O
5.2*
2
21
+
=
sense
O
R
V
I
05.0
max
=
Out
LD
V
ctrl
Isense
+
-
+
-
1.23 V
2.5 V
1
2
5
3
4
6
V
cc
50mV
OSC
GND
LED
AM04986v1
2
21
)(
R
RR
VctrlV
O
+
∗=
Vctrl
VctrlV
RR
O
)(
21
+
∗=