ARD00797

参考设计, MCP16251单电池升压转换器, 外部UVLO, 自动PFM/PWM运行

The from is a MCP16251 single cell boost converter with external UVLO reference design. The MCP16251 device is a compact, high efficiency, fixed frequency, synchronous step-up DC to DC converter. The very low quiescent current makes it ideal for battery-powered applications. This reference design provides an example of how to optimize applications powered from a single AA cell battery by incorporating a ultra low power external undervoltage lockout circuit with hysteresis. The converter will not restart if the battery voltage is lower than 1.14V and will stop working if the battery voltage drops below 0.83V. The external ULVO circuit drains approximately 0.1 to 0.4µA before start-up and 1 to 2µA after start-up.

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Input voltage: one AA primary or rechargeable battery

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Output voltage is 3.3V, output current is less than 125mA

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Typical efficiency up to 96%

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Start-up voltage is 1.15V

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Shutdown voltage is 0.83V

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Automatic PFM/PWM operation

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PWM switching frequency is 500KHz