基于NXP公司TEA1836XT + TEA1792T 65W笔记本适配器解决方案
原标题：NXP TEA1836XT + TEA1792T 65W笔记本适配器解决方案
nxp公司的TEA1836XT是高性能低成本DCM反激转换器控制器,所有功率水平都提供高效率和很低的功耗,输出功率高达75W,主要用在笔记本适配器,打印机,TV和计算机监视器.本文介绍了TEA1836XT通用特性,绿色特性和保护特性,应用框图,典型应用电路,以及采用TEA1836XT + TEA1792T的65 W笔记本适配器TEA1836DB1094输入和输出指标,电路图,材料清单,PCB布局图和变压器数据图.
The TEA1836XT is a high-featured low-cost DCM flyback converter controller. It provides a high efficiency at all power levels and very low no-load power consumption at nominal output voltage using burst mode operation.Burst mode is enhanced to minimize the risk of audible noise.
The TEA1836XT is intended for power supplies up to 75 W that require extended high peak power capabilities in order to supply high power without requiring a PFC.Typical applications are notebook adapters, printers, TVs or computer monitors.
The TEA1836XT is a controller IC for low-cost Switched Mode Power Supplies (SMPS) intended for flyback topologies. The built-in green functions provide high efficiency at all power levels.
At high power levels the flyback operates in QR mode. When lowering the power levels, the controller switches to DCM or frequency Reduction (FR) mode. The peak current is reduced to 25 % of the maximum peak current.
At low power levels, when the flyback switching frequency reaches 25 kHz, the flyback converter switches to burst mode. To ensure high efficiency at low power and excellent no-load power performance, a burst mode has been integrated that reduces the optocurrent to a minimum level. As the switching frequency in this mode has a minimum value of 25 kHz while the burst frequency is always below 800 Hz, the frequencies are outside the audible range.
During the non-switching phase of the burst mode, the internal IC supply current is reduced to further optimize efficiency.Valley switching is used in all operating modes.
The TEA1836XT includes an OverPower Protection (OPP). The OPP enables the controller to deliver 150 % peak power for a limited amount of time (200 ms) in case of overpower situations. If the output is shorted, the output power is limited to 100 % to keep the average power consumption lower than 5 W.
The TEA1836XT is realized in a high-voltage SOI (Silicon-On-Insulator) process. This process combines the advantages of a low-voltage process, like accuracy, high-speed protection functions, and control, while maintaining the high-voltage capabilities like high-voltage start-up and integrated X-cap discharge.
The TEA1836XT 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.
• DCM flyback controller IC for low-cost applications
• Wide supply voltage range (up to 30 V; 35 V peak allowed for 100 ms)
• Integrated high-voltage start-up current source
• Continuous minimum VCC regulation during start-up and protection via the HV pin, allowing a small VCC capacitor to be used
• Reduced optocoupler current (100uA) in burst mode, enabling low power consumption in no-load while keeping the output voltage in regulation
• Converter switching frequencies and burst mode operation outside the audible area
• Integrated active X-capacitor discharge
• Adjustable soft start
• Power-down mode activated by the PROTECT pin
• 150 % peak power capability
• Low supply current during normal operation (0.6 mA without driver load)
• Low supply current during non-switching state in burst mode (0.2 mA)
• Valley switching for minimum switching losses
• Quasi resonant controller can be used in combination with NXP Semiconductors SR controllers for optimal efficiency performance
• Burst mode and frequency reduction mode with fixed minimum peak current to maintain high efficiency at low output power levels
• Mains voltage independent OverPower Protection (OPP)
• Internal OverTemperature Protection (OTP)
• Integrated overpower time-out
• Integrated restart timer for system fault conditions
• Continuous mode protection using demagnetization detection
• Accurate OverVoltage Protection (OVP)
• General-purpose input for latched protection; can be used for external OverTemperature Protection (OTP)
• Driver maximum on-time protection
Typical applications are notebook adapters, printers, TVs or computer monitors.
TEA1836XT + TEA1792T 65 W笔记本适配器TEA1836DB1094
The board is designed for universal mains (90 V (AC) to 264 V (AC)). When a DC input voltage is applied, the power consumption is higher due to continuous activation of the X-capacitor discharge function.
The demo board incorporates two subcircuits:
• A DCM/QR type flyback converter
• A Synchronous Rectifier (SR)
The purpose of the demo board is to show the operation of the TEA1836XT and TEA1792TS in a single output supply. The performance is according today’s general standards including the DoE + CoC efficiency requirements. It can be used as a starting point for further product development.
图4. 65 W笔记本适配器TEA1836DB1094外形图
图5. 65 W笔记本适配器TEA1836DB1094电路图(TEA1836XT +TEA1792TS)
图6.65 W笔记本适配器TEA1836DB1094 PCB布局图(顶层)
图7.65 W笔记本适配器TEA1836DB1094 PCB布局图(底层)