TNY276P View Datasheet(PDF) - Power Integrations, Inc
Part Name
Description
MFG CO.
TNY276P
Power Integrations, Inc
'TNY276P' PDF : 24 Pages View PDF
TOP VIEW
HV DC
INPUT
Input Filter
Capacitor
CBP
S SSS
TinySwitch-III
EN/UV BP/M D
Y1-
Capacitor
T
r
a
n
s
f
o
r
m
e
r
Opto-
coupler
TNY274-280
Output Filter
Capacitor
DC
Maximize hatched copper
OUT
areas (
) for optimum
heatsinking
Figure 15. Recommended Circuit Board Layout for TinySwitch-III with Under-Voltage Lock Out Resistor.
PI-4278-013006
Thermal Considerations
The four SOURCE pins are internally connected to the IC lead
frame and provide the main path to remove heat from the device.
Therefore all the SOURCE pins should be connected to a copper
area underneath the TinySwitch-III to act not only as a single
point ground, but also as a heatsink. As this area is connected
to the quiet source node, this area should be maximized for
good heatsinking. Similarly for axial output diodes, maximize
the PCB area connected to the cathode.
Y-Capacitor
The placement of the Y-capacitor should be directly from the
primary input ï¬lter capacitor positive terminal to the common/
return terminal of the transformer secondary. Such a placement
will route high magnitude common mode surge currents away
from the TinySwitch-III device. Note – if an input π (C, L, C)
EMI ï¬lter is used then the inductor in the ï¬lter should be placed
between the negative terminals of the input ï¬lter capacitors.
Optocoupler
Place the optocoupler physically close to the TinySwitch-III
to minimizing the primary-side trace lengths. Keep the high
current, high voltage drain and clamp traces away from the
optocoupler to prevent noise pick up.
Output Diode
For best performance, the area of the loop connecting the
secondary winding, the output diode and the output ï¬lter
capacitor, should be minimized. In addition, sufï¬cient copper
area should be provided at the anode and cathode terminals
of the diode for heatsinking. A larger area is preferred at the
quiet cathode terminal. A large anode area can increase high
frequency radiated EMI.
11 E
2/06
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