Diodes Incorporated has introduced a high-efficiency synchronous boost converter. The AP72250 DIODES is targeted at progressive conversion in consumer and industrial applications where small form factors are a priority. This includes battery-powered devices, USB power supply units, power banks, supercapacitor charging equipment and measurement systems.
The AP72250 supports a switching frequency of 900kHz with a quiescent current of 20µA (I P ). It covers a wide input voltage range between 0.6 and 5.5 V, with a minimum input startup of 1 V, and has an output voltage range of 1.7 to 5.5 V. Integrated into this boost converter are a 20mΩ high-side power MOSFET and a 26mΩ low-side power MOSFET.
Several different operating modes can be selected for the AP72250, and these can be programmed according to the user's needs. They include pulse frequency modulation (PFM), ultrasonic mode (USM), and forced pulse width modulation (FPWM) mode.
This choice of modes allows engineers to adjust operation under heavy or light load conditions in order to maximize efficiency. As a result, even in light load situations, an efficiency of up to 89% can be achieved. Through USM mode, switching in the audible frequency range is avoided.
The AP72250 has excellent line and load transient responses and offers a seamless transition between boost and pass-through operation (in applications where this is required). The AP72250's peak current mode control scheme allows it to handle a wide range of input-to-output ratios.
Consequently, the number of external components required to support it is significantly lower than for competing solutions, and this keeps bill of materials (BOM) costs low. Undervoltage lockout, thermal shutdown, peak current limit, negative current limit and output short circuit protection functions are also included.