基于TEA1733的低成本綠色75W開關電源控制設計方案

NXP公司的TEA1733是低成本綠色75W開關電源(SMPS)控制器,用于固定頻率模式和反激拓撲.TEA1733集成了頻率抖動器以降低EMI,并集成了超功率保護(OPP),輸入欠壓保護(UVP),過壓保護(OVP),輸出OVP和超溫保護(OTP),可以用在需要效率和高性價比的75W功率電源解決方案.本文介紹了TEA1733主要特性, 方框圖, 典型配置框圖和典型應用框圖.

The TEA1733(L) is a low cost Switched Mode Power Supply (SMPS) controller IC　intended for flyback topologies. The TEA1733(L) operates in fixed frequency mode. To　reduce ElectroMagnetic Interference (EMI), frequency jitter has been implemented. For　Continuous Conduction Mode (CCM) operation, slope compensation is integrated.　The TEA1733(L) IC features an OverPower Protection (OPP). The controller can be set to　accept an overpower situation for a limited amount of time.

Two pins are reserved for protection purposes. Input UnderVoltage Protection (UVP) and　OverVoltage Protection (OVP), output OVP and OverTemperature Protection (OTP) can　be implemented with 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 the 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(L) 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.

TEA1733(L) 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 A)

? 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 at low power operation 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

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

??IC overtemperature protection

TEA1733(L) 應用:

? The devices can be used in all applications that require an efficient and cost-effective
power supply solution of up to 75 W.


圖1.TEA1733方框圖

圖2.TEA1733典型配置框圖

圖3.TEA1733典型應用框圖