Functional Description

TSM007

7/12

COMP input

This pin is connected to the current comparator

for current mode control. The pin should be

connected to the collector (primary side) of an

optocoupler which anode (secondary side) is

driven by the output of error amplifier.

The COMP input is used to set the reference level

for the current sense comparator. The current

sense threshold is set to (Vcomp - 2 * Vbe ) / 3.

Standby consumption

The low current value supply in stand by mode

reduces the consumption ..

When Brnout is below 2.5V, Vflitered below 200V

the PWM is off.

==> Icc = Istby.

RP = (Vfiltered-Vz)/Istby

In normal mode, the Vfiltered voltage can go up to

400V.

==> Rpmax dissipation = (Vfiltered-Vin)²/Rp

The Iin current is provided by the auxiliary

winding.

Let’s assume Vfiltered = 200V

Rp = 620K

Ω

Rpmax dissipation = 220mW

Output driver

The OUT totem pole output is capable to sink and

source more than 1.0A (peak) in order to direct

drive a power MOSFET..

Rp

R1

R2

VFiltered

D1

Raux

+

Cd

Brnout

2.5V

Out

Istby

Iin

Istby

1

2

3

4

5

6

8

Brnout

Vin

Out

CS

Comp

Ss

CT

Gnd

TSM007

Gnd

Vin

Out

Rb

28V