TNY263-268
Key Application Considerations
TinySwitch-II
vs.
TinySwitch
Table 2 compares the features and performance differences
between the TNY254 device of the
TinySwitch
family with the
TinySwitch-II
family of devices. Many of the new features
eliminate the need for or reduce the cost of circuit components.
Other features simplify the design and enhance performance.
Design
Output Power
Table 1 (front page) shows the practical maximum continuous
output power levels that can be obtained under the following
conditions:
1. The minimum DC input voltage is 90 V or higher for
85 VAC input, or 240 V or higher for 230 VAC input or
115 VAC input with a voltage doubler. This corresponds to
a filter capacitor of 3
µF/W
for universal input and 1
µF/W
for 230 VAC or 115 VAC with doubler input.
Function
Switching Frequency
and Tolerance
Temperature Variation
(0 - 100
°C)**
Active Frequency Jitter
Transformer
Audible Noise
Reduction
Line UV Detect
Current Limit Tolerance
Temperature Variation
(0 - 100
°C)**
Auto-Restart
TinySwitch
TNY254
44 kHz
±10%
(@25
°C)
+8%
N/A*
N/A*
TinySwitch-II
TNY263-268
TinySwitch-II
Advantages
132 kHz
±6%
(@25
°C)
• Smaller transformer for low cost
• Ease of design
+2%
• Manufacturability
• Optimum design for lower cost
±4
kHz
Yes - built into
controller
• Lower EMI minimizing filter
component costs
• Practically eliminates audible noise
with ordinary dip varnished
transformer – no special construction
or gluing required
• Prevents power on/off glitches
• Increases power capability and
simplifies design for high volume
manufacturing
• Limits output short-circuit current to
less than full load current
- No output diode size penalty.
• Protects load in open loop fault
conditions
- No additional components
required
• Allows
TinySwitch-II
to be powered
from a low voltage bias winding to
improve efficiency and to reduce
on-chip power dissipation
• Greater immunity to arcing as a
result of dust, debris or other
contaminants build-up
N/A*
±
11% (@25
°C)
-8%
N/A*
Single resistor
programmable
±
7% (@25
°C)
0%
6% effective on-time
BYPASS Pin
Zener Clamp
N/A*
Internally clamped to
6.3 V
DRAIN Creepage at
Package
0.037” / 0.94 mm
0.137” / 3.48 mm
*Not available.
** See typical performance curves.
Table 2. Comparison Between TinySwitch and TinySwitch-II.
10
E
4/04
POWERINT [ POWER INTEGRATIONS, INC. ]
