1. Product profile
1.1 General description
The TEA1721 is a small and low cost module Switched Mode Power Supply (SMPS)
controller IC for low power applications (up to 5 W) and operates directly from the rectified
universal mains input. The device includes a high voltage power switch (700 V) and has
been optimized for flyback converter topologies to provide high-efficiency over the entire
load range with ultra-low power consumption in the no-load condition. It provides a circuit
for start-up directly from the rectified mains voltage without any external bleeder circuits.
The converter operates as a regulated voltage source from no-load up to the maximum
output current and operates as current source that delivers the maximum current over a
broad output voltage range. Using the TEA1721, a low power converter can be built at
minimum cost and with the minimum number of external components.
The controller regulates the output voltage with primary-side sensing which eliminates the
need for an additional secondary feedback circuitry and simplifies the design. At higher
power levels, a frequency and current control mode is used. It operates with Burst mode
control at low power levels and no-load condition. The burst mode minimizes audible
noise and provides an energy saver state which reduces the power consumption in
no-load condition. The Burst mode frequency of 1750 Hz enables no-load power
consumption below < 30 mW at high mains input.
1.2 Features and benefits
Power features:
Low power SMPS controller with integrated power switch designed for applications up
to 5 W
700 V high voltage power switch for global mains operation
Primary sensing for control of the output voltage without optocoupler and secondary
feedback circuitry
Minimizes audible noise in all operation modes
USB battery charging and Energy Star 2.0 compliant
Jitter function for reduced EMI
TEA1721FT
HV start-up flyback controller with integrated MOSFET for 5 W
applications, 1750 Hz burst frequency
Rev. 1.1 — 7 June 2012 Product data sheet
