TPS5403DR

TPS5403是一款具有宽运行输入电压范围（4.5V至28V）的单片非同步降压稳压器。此器件执行内部斜坡补偿的电流模式控制来减少组件数量。 TPS5403还特有一个轻负载脉冲跳跃模式，此特性可在轻负载时减少为系统供电的输入电源的功率损失。 可使用一个外部电阻器将此转换器的开关频率设定在50kHz至1.1MHz之间。引入了频率展频操作以减少EMI。 添加了LX抗振铃来解决高频EMI问题。 具有频率折返功能的逐周期电流限制在过载情况下保护集成电路(IC)。

The TPS5403 is a 28-V, 1.7-A, step-down (buck) converter with an integrated high-side N-channel MOSFET. To improve performance during line and load transients, the device implements a constant frequency, current mode control which reduces output capacitance and simplifies external frequency compensation design. The TPS5403’s switching frequency is adjustable with an external resistor or fixed by connecting the frequency program pin to GND or leaving it unconnected. The TPS5403 starts switching at V_IN equal to 3.5 V. The operating current is 100 μA typically when not switching and under no load. When the device is disabled, the supply current is 1 μA typically. The integrated 120 mΩ high-side MOSFET allows for high efficiency power supply designs with continuous output currents up to 1.7 A. The TPS5403 reduces the external component count by integrating the boot recharge diode. The bias voltage for the integrated high-side MOSFET is supplied by an external capacitor on the BOOT to PH pins. The boot capacitor voltage is monitored by an UVLO circuit and will turn the high-side MOSFET off when the voltage falls below a preset threshold of 2.1 V typically. By adding an external capacitor, the slow start time of the TPS5403 can be adjustable which enables flexible output filter selection. To improve the efficiency at light load conditions, the TPS5403 enters a special pulse skipping mode when the peak inductor current drops below 300 mA typically. The frequency foldback reduces the switching frequency during startup and over current conditions to help control the inductor current. The thermal shut down gives the additional protection under fault conditions.

• 固定3.3V输出
• 4.5V至28V的宽输入电压范围
• 高达1.7A的最大持续输出负载电流
• 脉冲跳跃模式可在轻负载时实现高效率
• 10mA负载时效率超过80%
• 由一个外部电阻器设定的可调50kHz至1.1MHz的开关频率
• 峰值电流模式控制
• 逐周期过流保护
• 频率展频和抗振铃开关节点以减轻电磁干扰(EMI)问题
• 外部软启动
• 采用小外形集成电路(SOIC)8封装

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