LM5116

100V 宽输入电压同步降压控制器

The is a synchronous buck controller intended for step-down regulator applications from a high-voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting, and ease-of-loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high-input voltage applications.

The operating frequency is programmable from 50 kHz to 1 MHz. The LM5116 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation, for improved efficiency at light load conditions. A low quiescent current shutdown disables the controller and consumes less than 10 µA of total input current.

Additional features include a high-voltage bias regulator, automatic switch-over to external bias for improved efficiency, thermal shutdown, frequency synchronization, cycle-by-cycle current limit, and adjustable line undervoltage lockout. The device is available in a power enhanced HTSSOP-20 package featuring an exposed die attach pad to aid thermal dissipation.

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Emulated Peak Current Mode

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Wide Operating Range Up to 100 V

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Low IQ Shutdown < 10 µA

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Drives Standard or Logic Level _MOSFETs_

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Robust 3.5-A Peak Gate Drive

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Free-run or Synchronous Operation to 1 MHz

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Optional Diode Emulation Mode

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Programmable Output from 1.215 V to 80 V

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Precision 1.5% Voltage Reference

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Programmable Current Limit

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Programmable Soft-Start

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Programmable Line Undervoltage Lockout

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Automatic Switch to External Bias Supply

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HTSSOP-20 Exposed Pad

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Thermal Shutdown