2.4MHz 5.5A Step-Down Converter with I²C Interface

The RT5736 is a step-down converter that delivers a digitally programmable output from an input voltage supply of 2.5V to 5.5V. The output voltage is programmed through an I²C interface that can operate up to 3.4MHz.Using a proprietary architecture with synchronous rectification, the RT5736 is capable of delivering a continuous 5.5A and maintains high efficiency at load currents as low as 10mA. The regulator operates at a nominal fixed frequency of 2.4MHz, which reduces the external component counts. Additional output capacitance can be added to improve regulation during load transients without affecting stability.At moderate and light loads, Pulse Frequency Modulation (PFM) is used to operate in power-saving mode, with a typical quiescent current of 45μA at room temperature. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed frequency control, operating at 2.4MHz. In shutdown mode, the supply current is typically 0.1μA, which is excellent for reducing power consumption. The PFM mode can be disabled if the fixed frequency is preferred. The RT5736 is available in a small WQFN-20L 3.5x3.5 package. The recommended junction temperature range is -40°C to 125°C.