FSDM311A Fairchild Semiconductor, FSDM311A Datasheet - Page 3

• Manufacturer Part Number: FSDM311A
• Description: IC SWIT PWM GREEN OVP HV 8DIP
• Manufacturer: Fairchild Semiconductor

Specifications of FSDM311A

• Output Isolation: Isolated
• Frequency Range: 61 ~ 73kHz
• Voltage - Input: 7 ~ 20 V
• Voltage - Output: 650V
• Power (watts): 13W
• Operating Temperature: 25°C ~ 150°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• On Resistance (max): 14 Ohms
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Maximum Power Dissipation: 1400 mW
• Mounting Style: Through Hole
• Supply Current: 1.5 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

© 2007 Fairchild Semiconductor Corporation
FSDM311A • Rev.1.0.2
Pin Configuration
Pin Definitions
Pin #
6,7,8
1
2
3
4
5
Name
Drain
GND
Vstr
Vcc
Vfb
NC
Description
Ground. SenseFET source terminal on primary side and internal control ground.
Positive supply voltage input. Although connected to an auxiliary transformer winding,
current is supplied from pin 5 (Vstr) via an internal switch during start-up (see the Internal Block
Diagram in Figure 2). It is not until V
start-up switch opens and device power is supplied via the auxiliary transformer winding.
Feedback. Inverting input to the PWM comparator with its normal input level lies between 0.5V
and 2.5V. It has a 0.4mA current source connected internally, while a capacitor and opto-
coupler are typically connected externally. A feedback voltage of 4.5V triggers overload
protection (OLP). There is a time delay while charging external capacitor C
using an internal 5µA current source. This time delay prevents false triggering under transient
conditions, but allows the protection mechanism to operate under true overload conditions.
No Connection.
Start-up. This pin connects directly to the rectified AC line voltage source. At start-up, the
internal switch supplies internal bias and charges an external storage capacitor placed
between the Vcc pin and ground. Once the V
the capacitor.
SenseFET Drain. The drain pins are designed to connect directly to the primary lead of the
transformer and are capable of switching a maximum of 650V. Minimize the length of the trace
connecting these pins to the transformer to decrease leakage inductance.
Figure 3.
8-Lead DIP Pin Assignments (Top View)
CC
reaches the UVLO upper threshold (9V) that the internal
3
CC
reaches 9V, the internal switch stops charging
FB
from 3V to 4.5V
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