STMicroelectronics L6562A Evaluation Board STEVAL-ILL016V2 STEVAL-ILL016V2 STEVAL-ILL016V2 Data Sheet
Product codes
STEVAL-ILL016V2
Application information
TSM1052
8/15
4 Application
information
4.1
Typical application schematic
Figure 15. Typical adapter or battery charger application using the device
In the above application schematic, the device is used on the secondary side of a flyback
adapter (or battery charger) to provide an accurate control of voltage and current. The
above feedback loop is made with an optocoupler.
adapter (or battery charger) to provide an accurate control of voltage and current. The
above feedback loop is made with an optocoupler.
4.2
Voltage and current control
4.2.1 Voltage
control
The voltage loop is controlled via a first transconductance operational amplifier, the voltage
divider R
divider R
1
, R
2
, and the optocoupler which is directly connected to the output. Its possible to
choose the values of R1 and R2 resistors using Equation 1:
Equation 1
where Vout is the desired output voltage.
As an example, with R1 = 100 k
Ω and R2 = 27 kΩ, V
OUT
= 5.7 V
Rsense
Iout
Vout
Vctrl
GND
Vsense
Ictrl
OUT
Vcc
1.210 V
200 mV
+
-
+
-
+
1
2
3
5
4
6
R1
R2
TSM1052
Ric2
Ric1
Cic1
Cvc1
Rvc1
Rled
Rsense
Iout
Vout
Vctrl
GND
Vsense
Ictrl
OUT
Vcc
1.210 V
200 mV
+
-
+
-
+
1
2
3
5
4
6
R1
R2
TSM1052
Ric2
Ric1
Cic1
Cvc1
Rvc1
Rled
a)
b)
2
2
1
ref
out
R
)
R
R
(
V
V
+
⋅
=
ref
ref
out
2
1
V
)
V
V
(
R
R
−
⋅
=