UC3844B, UC3845B, UC2844B, UC2845B

http://onsemi.com

12

+

R

2R

1.0mA

EA

2(3)

5(9)

2.5V

1(1)

Error Amp compensation circuit for stabilizing current mode boost

and flyback topologies operating with continuous inductor current.

Figure 27. Isolated MOSFET Drive

Figure 28. Latched Shutdown

Figure 29. Error Amplifier Compensation

+

-

S

R

5.0V Ref

Q

7(11)

6(10)

5(8)

3(5)

Q1

Isolation

Boundary

+

-

0

50% DC

25% DC

NS

Np

Bias

+

Osc

R

R

R

2R

EA

5(9)

1(1)

2(3)

4(7)

8(14)

simple two transistor circuit can be used in place of the SCR as shown. All

resistors are 10 k.

MCR

101

2N

3905

2N

3903

+

R

2R

1.0mA

EA

2(3)

5(9)

2.5V

1(1)

Error Amp compensation circuit for stabilizing any current mode topology except

for boost and flyback converters operating with continuous inductor current.

Comp/Latch

7(12)

R

C

1.0 mA

T

+

-

0

+

-