Maxim Offers a New Digital Power-Supply Controller/Monitor with PMBus Communication
Maxim Integrated Products Inc. introduced the MAX8688, a chip to convert an all-analog power supply to a fully programmable, digital power-management solution. A complete digital power-supply controller/monitor, the MAX8688 uses PMBus™ for communication, and can be used to control/monitor up to a total of 127 power supplies on a single bus. The MAX8688 taps into existing analog power-management solutions to provide effective control and monitoring capabilities, all functionality previously only available in all-digital power supplies.
The MAX8688 facilitates the monitoring and control of the power supply by simply tapping into the existing, all-analog power supplies. The MAX8688 closes a slow loop around the power supply to bring utmost accuracy and control in setting the output voltage. By tapping into the enable, feedback node, and/or reference input, the MAX8688 provides efficient tracking, sequencing, and fine setting of the output voltage down to +/-0.2% accuracy over the operating temperature. Because the MAX8688 is in full control of the output, tasks like margining up or down and transitioning the output voltage at a controlled rate are quite simple. The MAX8688 uses the high accuracy of its integrated 12-bit, highly linear Adc to monitor output voltage, current, and on-board temperature. Consequently, multiple warning and fault thresholds are set and served with the flexibility of digital control.
In the PowerMind approach, a master microcontroller communicates to the MAX8688 through the PMBus. The system controller facilitates data logging and system-level control. Although the MAX8688 holds all the power supplies' peak temperature, output current, and output voltage data, the system controller can poll each power supply at fixed intervals and log the information intelligently for future analysis.
A graphical user interface (GUI) is supplied free of charge with the part. An engineer can use this GUI and the MAX8688 to implement a digitally programmable power supply. This is a great benefit to engineers and system integrators that do not want to discard legacy designs and risk a completely new architecture.
The MAX8688 is available in a space-saving, lead-free, 24-pin, 4mm x 4mm TQFN package. It operates over the -40°C to +85°C industrial temperature range. The MAX8688 requires a 3.3V +/-10% supply voltage, and can control output voltages from 0 to 5.5V. Prices start at $1.95 (10k-up FOB USA). A preassembled MAX8688 EV kit is available to reduce design time.
