Micrel MIC2619 1.2MHz PWM升压开关电源稳压方案

Micrel 公司的MIC2619是1.2MHz PWM升压开关电源稳压器，具有低功耗高输出电压的特性，最大输出电压35V，开关电流超过350mA。MIC2619的输入电压为2.8V-6.5V，PWM频率1.2MHz，反馈电压1.265V，可编程的过压保护（OVP），线电压调整小于1%，关断电流小于1uA。主要用在偏压电源如调谐器变容管偏压，高压显示器偏压等，DSL/宽带应用和恒流源电源。本文介绍了MIC2619主要特性，方框图和应用电路以及评估板电路图和材料清单。

The MIC2619 is a 1.2MHz pulse width modulated (PWM) step-up switching regulator that is optimized for low power, high output voltage applications. With a maximum output voltage of 35V, and a switch current of over 350mA, the MIC2619 can easily supply most high voltage bias applications, such as TV tuners.

The MIC2619 implements a constant frequency 1.2MHz PWM current-mode control scheme. The high frequency PWM operation saves board space by reducing external component sizes. The additional benefit of the constant frequency PWM control scheme as opposed to variable frequency control schemes is lower output noise and smaller input ripple injected back to the battery source.

The MIC2619 has programmable overvoltage protection to ensure output protection in case of fault condition. The MIC2619 is available in a low profile Thin SOT-23 6- pin package. The MIC2619 has a junction temperature range of –40℃ to +125℃.
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