Low Quiescent, High-Efficiency 3A Buck-Boost Converter with I2C Interface

The RT6166 is a high-efficiency, single-inductor and Advanced Constant On-Time (ACOT^®) monolithic synchronous buck-boost converter that can deliver up to 3A output current from an input voltage range of 2V to 5.5V.It can regulate the digitally programmable output voltage from 1.8V to 4.975V, making it suitable for a wide range of input supply applications, regardless of whether the input voltage is lower, higher than, or equal to the output voltage. The ACOT^® control architecture features outstanding line/load transient response, seamless transition between buck and boost modes, and provides stable operation with small ceramic output capacitors without the need for complicated external compensation.The RT6166 features an I²C interface for programmable output voltage, ultra-sonic mode control, VOUT DVS slew-rate adjustment, and device status monitoring.The target output voltage can also be switched through the external VSEL pin to perform DVS (Dynamic Voltage Scaling), and the ramp-up slew-rate and ramp mode of DVS can be set by configuring the related registers.The RT6166 operates with automatic PFM (Pulse Frequency Modulation) mode, featuring a low quiescent current design of typically 4μA, maintaining high efficiency during light load operation.At higher loads, the device automatically switches to a 2.2MHz fixed frequency control, effectively smoothing out the switching ripple voltage with small package filtering elements. The integrated low R_DS(ON) power MOSFETs exhibit excellent efficiency under heavy load conditions. In shutdown mode, the supply current is typically 0.1μA, contributing to reduce power consumption. The PFM mode can be disabled if a fixed frequency is required. The RT6166 is housed in a compact WL-CSP-15B 1.4x2.3 (BSC) package.The recommended junction temperature range is -40°C to 125°C, and the ambient temperature range is -40°C to 85°C.