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.

4.2

Voltage and current control

4.2.1

Voltage control

The voltage loop is controlled via a first transconductance operational amplifier, the voltage

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

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

−

⋅

=