The RAA211651 is an integrated 60V, 5A synchronous buck regulator with the Constant On-Time (COT) control scheme. It supports a wide range of input voltage from 4.5V to 60V and adjustable output voltage (0.8V to maximum duty cycle * VIN). It also features a very low quiescent current, typically 10μA at 24V input. The modulation scheme used allows for high efficiency at all output load levels, especially at light-load conditions.
The RAA211651 is based on the COT modulator, where the on-time is determined by the input voltage level and the resistor connected to the SET pin. The switching frequency varies with the load. At light load, switching frequency drops reducing the switching losses. Also, with internal compensation, the regulator works in Diode Emulation mode reducing the losses at light-load conditions.
To limit inrush current during startup the RAA211651 has 2ms fixed internal soft-start time. It can also be programed by an external capacitor. The RAA211651 also provides programmable startup delay time for sequencing purposes.
The RAA211651 provides comprehensive protections including undervoltage lockout, overcurrent (positive and negative), overvoltage, and over-temperature protections.
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