TNY253/254/255
TinySwitch™ Family
Energy Efficient, Low Power Off-line Switchers
Product Highlights
Lowest Cost, Low Power Switcher Solution
• Lower cost than RCC, discrete PWM and other integrat-
ed/hybrid solutions
• Cost effective replacement for bulky linear adapters
• Lowest component count
• Simple ON/OFF control – no loop compensation devices
• No bias winding – simpler, lower cost transformer
• Allows simple RC type EMI filter for up to 2 W from
universal input or 4 W from 115 VAC input
Extremely Energy Efficient
• Consumes only 30/60 mW at 115/230 VAC with no load
• Meets Blue Angel, Energy Star, Energy 2000 and 200 mW
European cell phone requirements for standby
• Saves $1 to $4 per year in energy costs (at $0.12/kWHr)
compared to bulky linear adapters
• Ideal for cellular phone chargers, standby power supplies for
PC, TV and VCR, utility meters, and cordless phones.
High Performance at Low Cost
• High-voltage powered – ideal for charger applications
• Very high loop bandwidth provides excellent transient
response and fast turn on with practically no overshoot
• Current limit operation rejects line frequency ripple
• Glitch free output when input is removed
• Built-in current limit and thermal protection
• 44 kHz operation (TNY253/4) with snubber clamp
reduces EMI and video noise in TVs and VCRs
• Operates with optocoupler or bias winding feedback
Description
The TinySwitch family uses a breakthrough design to provide
the lowest cost, high efficiency, off-line switcher solution in
the 0 to 10 W range. These devices integrate a 700 V power
MOSFET, oscillator, high-voltage switched current source,
current limit and thermal shutdown circuitry. They start-up
and run on power derived from the DRAIN voltage, eliminat-
ing the need for a transformer bias winding and the associated
circuitry. And yet, they consume only about 80 mW at no load,
from 265 VAC input. A simple ON/OFF control scheme also
eliminates the need for loop compensation.
+
Wide-Range
High-Voltage
DC Input
–
TinySwitch
D
EN
BP
S
Figure 1. Typical Standby Application.
+
DC
Output
–
PI-2178-022699
TinySwitch Selection Guide
ORDER
PART
NUMBER
TNY253P
TNY253G
TNY254P
TNY254G
TNY255P
TNY255G
PACKAGE
DIP-8
SMD-8
DIP-8
SMD-8
DIP-8
SMD-8
Recommended Range
for Lowest System Cost*
230 VAC or
115 VAC
w/Doubler
85-265
VAC
0-4 W
0-2 W
2-5 W
1-4 W
4-10 W 3.5-6.5 W
Table 1. *Please refer to the Key Application Considerations section
for details.
The TNY253 and TNY254 switch at 44 kHz to minimize EMI
and to allow a simple snubber clamp to limit DRAIN spike
voltage. At the same time, they allow use of low cost EE16 core
transformers to deliver up to 5 W. The TNY253 is identical to
TNY254 except for its lower current limit, which reduces output
short-circuit current for applications under 2.5 W. TNY255
uses higher switching rate of 130 kHz to deliver up to 10 W
from the same low cost EE16 core for applications such as PC
standby supply. An EE13 or EF13 core with safety spaced
bobbin can be used for applications under 2.5 W. Absence of
a bias winding eliminates the need for taping/margins in most
applications, when triple insulated wire is used for the secondary.
This simplifies the transformer construction and reduces cost.
February 2012
