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.
TEA1721主要特性和优势:
电源特性:
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
绿色特性:
Enables no-load power consumption < 30 mW
Very low supply current in no-load condition with energy saver mode
Incorporates a high voltage start-up circuit with zero current consumption under normal switching operation
Available in halogen-free and Restriction of Hazardous Substances (RoHS) SO7 Package
保护功能:
OverVoltage Protection (OVP) on Feedback control (FB) pin with auto-restart
UnderVoltage LockOut (UVLO) protection on IC supply pin
OverTemperature Protection (OTP)
Soft-start by reduced peak current for zero and low output voltage
Demagnetization protection for guaranteed discontinuous conduction mode operation
Open and short-circuit protection of the Feedback control (FB) pin
Short-circuit protection of the charger output
TEA1721应用:
Battery chargers for cellular phones and other low power adapters up to 5 W
Standby supply for TV and desktop PC
Power supply for White Goods applications
图1.TEA1721方框图
TEA1721FT 5 W GreenChip SP小型演示板
This user manual describes a 5 W Constant Voltage (CV) or Constant Current (CC) universal input power supply for mobile phone adapters and chargers. This demo board is based on the GreenChip SP TEA1721FT.
GreenChip SP TEA1721FT enables only 5 % output voltage tolerance at dynamic load behavior with low no-load power dissipation <40 mW. The TEA1721FT design ensures a low external component count for cost-effective applications. In addition, the TEA1721FT provides advanced control modes for optimal performance. The TEA1721FT integrates the 700 V power MOSFET switch and SMPS controller.
5 W GreenChip演示板特性:
• Has only 5 % output voltage tolerance at dynamic load behavior
• Enables low no-load power dissipation <40 mW
• Low component count for a cost-effective design
• Advanced control modes for optimal performance
• SMPS controller with integrated power MOSFET switch
• 700 V high-voltage power switch for global mains operation
• Primary sensing at end-of-conduction for accurate output voltage control
