描述 Description

The LM1771 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.

特性 Features

? Input Voltage Range of 2.8 V to 5.5 V
? 0.8-V Reference Voltage
? Precision Enable
? No Compensation Required
? Constant Frequency Across Input Range
? Low Quiescent Current of 400 μA
? Internal Soft-Start
? Short Circuit Protection
? 6-Pin WSON Package and 8-Pin VSSOP Package