原标题：NXP TEA1733 GreenChip III 75瓦开关电源控制方案

　　NXP 公司的TEA1733T, TEA1733P, TEA1733LT和TEA1733LP是低成本 GreenChip III 75瓦开关电源(SMPS)控制器，适用于反激拓扑。采用固定频率模式和频率抖动，以降低EMI。输入电压12V到30V，保护包括过功率保护(OPP)，输入欠压保护(UVP)和过压保护(OVP)，输出OVP和超温保护(OTP)。控制功率达75W。本文介绍了TEA1733x主要特性，方框图以及典型配置图和典型应用电路图。

　　TEA1733(L)T; TEA1733(L)P GreenChip III SMPS control IC

　　The TEA1733T, TEA1733P, TEA1733LT and TEA1733LP are low cost Switched Mode Power Supply (SMPS) controller ICs intended for flyback topologies. They operate in fixed frequency mode. To reduce ElectroMagnetic Interference (EMI), frequency jitter has been implemented. Slope compensation is integrated for Continuous Conduction Mode (CCM) operation.

　　The TEA1733(L) includes OverPower Protection (OPP). This enables the controller to operate under overpower situations for a limited amount of time.

　　Two pins, VINSENSE and PROTECT, are reserved for protection purposes. Input UnderVoltage Protection (UVP) and OverVoltage Protection (OVP), output OVP and OverTemperature Protection (OTP) can be implemented using a minimal number of external components.

　　At low power levels the primary peak current is set to 25 % of the maximum peak current and the switching frequency is reduced to limit switching losses. The combination of fixed frequency operation at high output power and frequency reduction at low output power provides high-efficiency over the total load range.

　　The TEA1733 series enables low cost, highly efficient and reliable supplies for power requirements up to 75 W to be designed easily and with a minimum number of external components.

　　TEA1733x主要特性：

　　SMPS controller IC enabling low-cost applications

　　Large input voltage range (12 V to 30 V)

　　Very low supply current during start-up and restart (typically 10 μA)

　　Low supply current during normal operation (typically 0.5 mA without load)

　　Overpower or high/low line compensation

　　Adjustable overpower time-out

　　Adjustable overpower restart timer

　　Fixed switching frequency with frequency jitter to reduce EMI

　　Frequency reduction with fixed minimum peak current to maintain high-efficiency at low output power levels

　　Slope compensation for CCM operation

　　Low and adjustable OverCurrent Protection (OCP) trip level

　　Adjustable soft start operation

　　Two protection inputs (e.g. for input UVP and OVP, OTP and output OVP)

　　IC overtemperature protection

　　TEA1733应用：

　　All applications requiring efficient and cost-effective power supply solutions to 75 W.

　　图1。TEA1733x方框图

　　图2。TEA1733x典型配置图

　　图3。TEA1733x典型应用电路图