TC105

DS21349B-page 6

© 2002 Microchip Technology Inc.

4.0

APPLICATIONS

4.1

Circuit Examples

Figure 4-3 shows a TC105 using a PNP switching

of the FZT749.

The circuit of Figure 4-4 utilizes a P-channel MOSFET

switching transistor (Silconix Si9430). This transistor is

a member of the Littlefoot™ family of small outline

MOSFETs.

FIGURE 4-1:

SOFT START CIRCUIT

FIGURE 4-2:

EXTERNAL TRANSISTOR CONNECTION

TC105

4

SHDN

SHDN/SS

TC105

4

0.033

µF

SHDN/SS

Shutdown Not Used

470K

Shutdown Used

ON

OFF

(From System

Control Logic)

+

+

–

–

470K

0.033

µF

TC105

1

Q

L

D

EXT

TC105

1

P

L

D

EXT

P-Channel MOSFET

PNP Bipolar Transistor

–

+

–

+

–

+