FSD200B Просмотр технического описания (PDF) - Fairchild Semiconductor

Номер в каталоге

Компоненты Описание

производитель

FSD200B

Green Mode Fairchild Power Switch (FPS™)

Fairchild Semiconductor 

Pin Definitions

FSD210B, FSD200B

Pin Number

1, 2, 3

4

5

7

8

Pin Name

GND

Vfb

Vcc

Drain

Vstr

Pin Function Description

Sense FET source terminal on primary side and internal control ground.

The feedback voltage pin is the inverting input to the PWM comparator and

it has a normal input level between 0.5V and 2.5V. It has a 0.25mA current

source connected internally while a capacitor and optocoupler are typically

connected externally. A feedback voltage of 4.5V triggers over load protec-

tion (OLP). There is a time delay while charging external capacitor Cfb from

3V to 4.5V using an internal 5uA current source. This time delay prevents

false triggering under transient conditions, but still allows the protection

mechanism to operate under true overload conditions.

<FSD210B>

Positive supply voltage input. Although connected to an auxiliary transform-

er winding, current is supplied from pin 8 (Vstr) via an internal switch during

startup (see Internal Block Diagram section). It is not until Vcc reaches the

UVLO upper threshold (8.7V) that the internal start-up switch opens and de-

vice power is supplied via the auxiliary transformer winding.

<FSD200B>

This pin is connected to a storage capacitor. A high voltage regulator laid be-

tween pin 8 (Vstr) and this pin, provides supply voltage to the device during

startup and normal operation. The FSD200B eliminates the need for an aux-

iliary bias winding and associated external components.

The drain pins are designed to connect directly to the primary lead of the

transformer and are capable of switching a maximum of 700V for 7DIP and

670V for 7LSOP. Minimizing the length of the trace connecting these pins to

the transformer will decrease leakage inductance.

This pin connects directly to the rectified AC line voltage source for both the

FSD200B and FSD210B.

For the FSD210B, at start up the internal switch supplies internal bias and

charges an external storage capacitor placed between the Vcc pin and

ground. Once the Vcc reaches 8.7V, the internal switch is opened.

For the FSD200B, an internal high voltage regulator provides constant sup-

ply voltage.

Pin Configuration

7DIP

7LSOP

GND 1

GND 2

GND 3

Vfb 4

8 Vstr

7 Drain

5 Vcc

Figure 5. Pin Configuration (Top View)

3

Share Link: