Energy Efficient, Offline Switcher with Enhanced
Flexibility and Extended Power Range
Lowest System Cost with Enhanced Flexibility
• 650 V rating optimized for non-active PFC applications
• Simple ON/OFF control, no loop compensation needed
• Selectable current limit through BP/M capacitor value
• Higher current limit extends peak power or, in open frame
applications, maximum continuous power
• Lower current limit improves efficiency in enclosed adapters/
• Allows optimum TinySwitch-LT choice by swapping
devices with no other circuit redesign
• Tight I2f parameter tolerance reduces system cost
• Maximizes MOSFET and magnetics power delivery
• Minimizes max overload power, reducing cost of
transformer, primary clamp & secondary components
• ON-time extension – extends low-line regulation range/hold-up time
to reduce input bulk capacitance
• Self-biased: no bias winding or bias components
• Frequency jittering reduces EMI filter costs
• Pin-out simplifies heat sinking to the PCB
• SOURCE pins are electrically quiet for low EMI
Enhanced Safety and Reliability Features
• Accurate hysteretic thermal shutdown protection with
automatic recovery eliminates need for manual reset
• Auto-restart delivers <3% of maximum power in short-circuit and
open loop fault conditions
• Output overvoltage shutdown with optional Zener
• Very low component count enhances reliability and enables
single-sided printed circuit board layout
• High bandwidth provides fast turn on with no overshoot and
excellent transient load response
• Extended creepage between DRAIN and all other pins improves field
EcoSmart™– Extremely Energy Efficient
• Easily meets all global energy efficiency regulations
• No-load <150 mW at 265 VAC without bias winding,
<50 mW with bias winding
• ON/OFF control provides constant efficiency down to very light loads
– ideal for mandatory CEC regulations
• Chargers/adapters for cell/cordless phones, PDAs, digital cameras,
MP3/portable audio, shavers, etc.
• DVD/PVR and other low power set top decoders
• Supplies for appliances, industrial systems, metering, etc.
TinySwitch™-LT incorporates a 650 V power MOSFET, oscillator,
high-voltage switched current source, current limit (user selectable) and
thermal shutdown circuitry. The IC family uses an ON/OFF control
scheme and offers a design flexible solution with a low system cost and
extended power capability.
Figure 1. Typical Application.
Output Power Table
230 VAC ± 15%
6 W 11 W
5 W 8.5 W
6 W 11.5 W
7 W 15 W
8 W 18 W
Table 1. Output Power Table.
1. Minimum continuous power in a typical non-ventilated enclosed adapter
measured at +50 °C ambient. Use of an external heat sink will increase
2. Minimum peak power capability in any design or minimum continuous power
in an open frame design (see Key Applications Considerations).
3. Packages: P: DIP-8C, D: SO-8C. See Part Ordering Information.
4. See Key Application Considerations.