Automotive boost controller regulates Class D audio and saves PCB space
Class-D audio amplifiers in automotive infotainment systems can be regulated by the MAX25203. The multi-phase synchronous boost controller features both programmable gate drive voltage and current limit blanking time, as well as accurate current balancing, says Analog Devices, and operates at a high switching frequency to reduce the bill of materials cost and shrink PCB space by 36 per cent.
The MAX25203 joins the existing MAX25201 and MAX25202 single/dual boost controllers, both designed for lower power applications. It can be used to generate backlight and Class-D audio amplifier voltages
The MAX25203 controller battery input voltage ranges from 4.5 to 42V and operates down to 1.8V after start-up. It sustains an absolute maximum output voltage of up to 70V and features a low shutdown supply current of 5microA. The MAX25203 offers I²C bus diagnostics including die temperature, phase current monitoring and optional true shutdown to improve system reliability. Output voltage is scalable via the PWM input or I²C interface and a sync-out feature supports additional phases for higher power systems.
A factory programmable gate drive voltage from 5.5 to 10V increases power density by reducing MOSFET RDS(on) loss. This increases efficiency and lowers cost, says Analog Devices.
Also included is a programmable current limit blanking time which supports short peak current events without power supply overdesign, to further reduce cost.
The controller has a ± five per cent current share accuracy from phase-to-phase which serves to reduce the inductor size, explains the company.
In addition, resistor programmable switching frequency up to 2.1MHz improves EMI and reduces external components’ size and count.
The MAX25203 is available as of now in a 32-Lead TQFN-CU packaging. There is also an evaluation board available, the MAX25203EVKIT.
