LM1771

具有精密启用和无需外部补偿组件的低压同步降压控制器

The device is an efficient synchronous buck switching controller with a precision enable requiring no external compensation. The constant ON-time control scheme provides a simple design free of compensation components, allowing minimal component count and board space. The precision enable pin allows flexibility in sequencing multiple rails and setting UVLO. The LM1771 also incorporates a unique input feedforward to maintain a constant frequency independent of the input voltage. The LM1771 is optimized for a low-voltage input range of 2.8 V to 5.5 V and can provide an adjustable output as low as 0.8 V. Driving an external high-side PFET and low-side NFET, it can provide efficiencies as high as 95%.

Three versions of the LM1771 are available depending on the switching frequency desired for the application. Nominal switching frequencies are in the range of 100 kHz to 1000 kHz.

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Input Voltage Range of 2.8 V to 5.5 V

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0.8-V Reference Voltage

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Precision Enable

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No Compensation Required

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Constant Frequency Across Input Range

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Low Quiescent Current of 400 µA

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Internal Soft-Start

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Short Circuit Protection

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6-Pin WSON Package and 8-Pin VSSOP Package