MAXREFDES1213: Smart electronic load using the MAX32630FTHR and MAX11311

The MAXREFDES1213 is a reference design showcasing the MAX32630FTHR and MAX11311, as well as several other Maxim products, that demonstrates a small size, low-cost, portable electronic load (E-load) for testing power converters and PMICs. The MAX32630FTHR is an Arm®-core-based, low-power microcontroller board whose main purpose is to facilitate communication between the PC’s graphical user interface (GUI) software and the E-load. The MAX11311 12-port programmable mixed-signal I/O (PIXI™) with 12-bit ADC, 12-bit DAC, analog switches, and GPIO is used to control the load currents and measure various parameters of the E-load.

Other Maxim components in this design include the MAX44251 20V, ultra-precision, low-noise op amp, which is used to control the load currents; the MAX8614 dual-output (+ and -) DC-DC converter for biasing the MAX11311; the MAX8881 12V, ultra-low-IQ, low-dropout linear regulator with power-OK (POK), which is used to power different components on the E-load board; and the MAX44243 36V, low-noise, precision quad op amp, which is used for signal conditioning.

The power that is dissipated in the power MOSFETs is drained using a heatsink with a cooler fan (the Thermaltake® CLP0556). The MAX6645 automatic PWM fan-speed controller with overtemperature output controls the fan speed based on the heatsink temperature.