The STEVAL-ISA172V1 evaluation board provides the hardware platform for the 2kW fully digital AC-DC power supply described in the Technical View in this issue, on pages 26-27. It consists of two sections: a two-phase interleaved PFC circuit, and a DC-DC phase-shifted full-bridge converter. Each section is controlled by separate STM32F334 microcontrollers.
The power supply achieves high efficiency and a power factor of very close to unity, and produces low harmonic distortion across a wide range of input voltages and loads.
The STEVAL-ISA098V1 demonstration board is a step-down switching power supply based on the L7985A step-down regulator. The board provides up to 2A current to the load from an input voltage ranging between 4.5V and 38V. The output voltage can be set in a range from 0.6V up to the same value as the input voltage.
The STEVAL-ISA159V1 evaluation board is based on the L6984, a high-efficiency synchronous step-down regulator IC capable of providing an output of up to 400mA. The fixed 3.3V output requires no external resistor divider. The board features a low-consumption mode which maximises efficiency at light loads with controlled output-voltage ripple.
The STEVAL-ISA165V1 demonstrates the performance of the SRK2001 synchronous-rectification controller. The SRK2001 implements a control scheme specific for secondary-side synchronous rectification in LLC resonant converters that use a transformer with centre-tap secondary winding, for full-wave rectification.
The board includes two synchronous-rectification MOSFETs in a TO-220 package, and can be easily implemented in an existing converter as a substitute for rectifier diodes.