7.1 Overview

The TPS61230A is a high efficiency synchronous boost converter with integrating the 21-mΩ low side FET and 18-mΩ high side FET. The device could deliver up to 12-W output power with 5.5-V maximum output voltage from single cell Li-Iron battery. TPS61230A uses a quasi constant on-time valley current mode which provides an excellent transient response. The TPS61230xA typically operates at a quasi-constant 1.15-MHz frequency pulse width modulation (PWM) at the moderate to heavy load currents, allows the use of small inductor and capacitors to achieve a compact solution size.

During the PWM operation, a simple circuit predicts the required on time (with the VIN / VOUT ratio) of the ow-side FET. At the beginning of each switching cycle, the low-side FET turns on and the inductor current ramps up to the peak current determined by the on-time and the inductance. Once the on-timer expires, the high-side FET turns on and the inductor current decays to a preset valley current threshold determined by the Error Amplifier’s output. The switching cycle repeats again by calculating the on time and activating the low-side FET.

At the light load currents, TPS61230A operates in Power Save Mode with pulse frequency modulation (PFM) and improves the efficiency under the light load.

Internal soft-start and loop compensation simplifies the design process and minimizes the number of external components.