TSM1011

Compensation

6/9

6

COMPENSATION

The voltage-control transconductance operational

amplifier can be fully compensated. Both its

output and negative input are directly accessible

for external compensation components.

An example of a suitable compensation network is

shown in

The current-control transconductance operational

amplifier can be fully compensated. Both of its

output and negative input are directly accessible

for external compensation components.

An example of a suitable compensation network is

shown in

Fig. 4: Schematic of compensation network

7

START UP AND SHORT CIRCUIT CONDITIONS

Under start-up or short-circuit conditions the

TSM1011 is not provided with a high enough

supply voltage. This is due to the fact that the chip

has its power supply line in common with the

power supply line of the system.

Therefore, the current limitation can only be

ensured by the primary PWM module, which

should be chosen accordingly.

If the primary current limitation is not considered

to be precise enough for the application, then a

sufficient supply for the TSM1011 has to be

ensured under all conditions. This means that it is

necessary to add some circuitry to supply the chip

with a separate power line. This can be achieved

in numerous ways, including an additional winding

on the transformer.

+

CS

DS

D

R2

R1

Rsense

Rvc1

22K

Cvc1

2.2nF

Ric1

22K

OUT+

OUT-

+

Cic1

2.2nF

IL

Ric2

1K

R5

1K

R4

10K

R3

100

IL

Vsense

+

Rlimit

Vcc

28V

Vcc

Cv-

Out

Gnd

Cc-

Cc+

Cv+

Vref

1

4

5

3

7

CV

CC

TSM1011