LM5157中文资料采用双随机展频技术的 6A/4A、50V、2.2MHz 宽输入电压升压、反激式和 SEPIC 转换器数据手册TI规格书

描述 Description

The LM5157 device is a wide input range, non-synchronous boost converter with integrated 50-V power switch.

The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a single-cell battery with a minimum of 2.9 V. It can operate with an input supply voltage as low as 1.5 V if the BIAS pin is greater than 2.9 V.

The BIAS pin operates up to 45 V (50-V absolute maximum). The switching frequency is dynamically programmable with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response. To reduce the EMI of the power supply, the device provides a selectable Dual Random Spread Spectrum, which reduces the EMI over a wide frequency range.

The device features an accurate peak current limit over the input voltage, which avoids overdesigning power inductor. Low operating current and pulse-skipping operation improve efficiency at light loads.

The device has built-in protection features such as overvoltage protection, line UVLO, thermal shutdown, and selectable Hiccup mode overload protection. Additional features include low shutdown IQ, programmable soft start, precision reference, a power-good indicator, and external clock synchronization.

特性 Features

• Suited for wide operating range for battery applications
• 48-V maximum output (50-V abs max)
• Input transient protection up to 50 V
• Low shutdown current (IQ ≤ 2.6 µA)
• Small solution size and low cost
• 16-pin QFN package (3 mm × 3 mm)
• Accurate current limit (see the Device Comparison Table)
• EMI mitigation
• Lead-less package
• Higher efficiency with low-power dissipation
• Fast switching, small switching loss
• Avoid AM band interference and crosstalk
• Dynamically programmable wide switching frequency from 100 kHz to 2.2 MHz
• Integrated protection features
• Selectable hiccup mode overload protection
• OVP protection
• Accurate ±1% accuracy feedback reference
• PGOOD indicator
• Create a custom design using the LM5157x with the WEBENCH Power Designer