In today's new electronic systems, understanding the operating state of a voltage regulator may be the last blind spot, because there is usually no way to directly configure or remotely monitor critical operating parameters. When the regulator output voltage drifts or is overheated, understanding these parameters is often critical to reliable operation. These parameters must be detected and acted upon based on the test results to prevent possible fault events.

Digital Power System Management (DPSM) allows designers to simplify and accelerate system characterization, system optimization, and data mining during prototype generation, deployment, and field operations. The DPSM method is used in such systems to monitor voltage regulator performance and report regulator health in order to take corrective action to prevent the regulator from exceeding performance specifications or even malfunctioning. DPSM allows users to take action based on information gathered from the load and system, providing the following benefits:

Faster listing

        ●   Change power parameters without redesigning the PCB

● Quick system feature testing, system optimization and data mining

Load level benefit

● Control power accuracy with time and temperature changes

● Adjust margin to test FPGA tolerance

● Improve system efficiency through load shedding

System level benefits

● Use digital board level power diagnostics

● Monitor and determine the power consumption of the entire system

● Fault management / fault record  

Deployment benefits

● Power consumption trends, detection of fluctuations and changes over time

● Conduct predictive data analysis to minimize operating costs

● Make energy management decisions

In the development phase, digital control of the analog power supply through a simple PC connection is especially useful, allowing the system to quickly enter normal operation. On some boards, there may be up to 50 point-of-load (POL) voltage rails, and system designers need to be able to quickly and easily monitor and regulate supply voltages, power up/down sequencing, set operating voltage limits, and read Such as voltage, current and temperature parameters, and access to detailed fault records. In such a system, high accuracy is extremely important to maintain tight control of the voltage rail while achieving maximum performance.

 

DPSM is quickly adopted in many systems because it provides accurate information for the power system and can autonomously control and check many voltages. Linear Technology offers several digital power products that enable this type of functionality, and the LTC3886, which was introduced a while ago, is an example.

 

The LTC3886 is a 60V input dual output synchronous buck DPSM controller that produces an output voltage of up to 13.8V. This high input voltage is ideal for harsh environments common in factory automation, industrial, medical, communications, and avionics applications.

 

The LTC3886 can be configured as a dual or single output and can be stacked up to 6 phases to support load currents up to 120A. The interleaved clock phase of two, three, four, or six phase operation reduces input and output ripple, which reduces input and output capacitance. Its serial I 2 C interface allows system designers and remote operators to set and monitor system power and power consumption through commands. The ability to digitally change power parameters can reduce time-to-market and downtime, as there is no need to change physical hardware, circuitry, or system materials in general.

 

Figure 1: LTC3886 Schematic Diagram for Converting 48VIN to 5V/15A and 12V/15A

 

The LTC3886's two-wire serial interface allows for margin adjustment, trimming, and ramping the output ramp down and down at a configurable slew rate. Input and output current and voltage, output power, temperature, run time, and peak are all readable. To evaluate the LTC3886 and other Linear Technology products, you must download the award-winning, free-to-use and easy-to-use LTpower Play ® GUI.

This interface provides tools for seamless integration of DPSM products with existing embedded systems and architectures, board mounted controllers (BMC), and Intelligent Platform Management Interface (IPMI) capabilities. For ease of use, especially during the earliest hardware development and testing phases, it is common practice to connect DPSM devices through a GUI running on a PC and through a USB to PMBus communication converter tool (often called a dongle). The GUI provides control and monitoring of critical operating parameters such as power consumption, voltage, sequencing, margining, and even fault logging.

 

Since 50 or more power rails are not uncommon for a system board, such boards are often densely packed with electronic components, and the DPSM circuit cannot occupy too much space. In addition, a large number of rails must be used very easily and can be controlled. Such a solution must operate autonomously or with a system host processor to obtain commands, implement control, and report telemetry information.

in conclusion:

DPSM provides system designers with a tool that allows them to control power with a simple PC connection and digital interface. This capability is invaluable during the development and commissioning phases, enabling designers to get the system into normal operation quickly and to control and regulate supply voltages, limits and sequencing. Margin testing is easier because the entire test can be controlled with a few commands that are sent via I2C / PMBus.

 

DPSM provides users with power consumption data that allows for intelligent energy management decisions that reduce overall power consumption. Power system data about the health of the power supply can be sent back to the OEM, effectively opening up the blind spots associated with the DC/DC converter. It can detect drift or overheating of the regulator's output voltage over time and take action to prevent possible fault events. If the board is returned, the fault log can be read back to determine what fault has occurred, the board temperature at which the fault occurred, and the time the fault occurred. This data can be used to quickly determine the root cause of the failure, or to determine if the system is operating beyond the specified operating limits, or to improve the design of future products. Digital power system management is a powerful tool for systems with a large number of rails and OEMs who want to avoid voltage rail blind spots.