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It is a great challenge for power-supply designers to convert power from a distributed bus to individual Points-of-Load (PoLs). For instance, FPGAs and ASICs in industrial and infrastructure systems need to deliver maximum efficiency and peak performance at a reduced bill-of-materials cost, and with the smallest possible board footprint.

Power modules provide a way to fulfil these requirements, since they integrate the controller, synchronous MOSFETs, inductor, compensation network and protection circuitry in one compact package.

But design engineers face the dilemma of whether to go the analog or digital route in an effort to achieve the right balance between functionality and cost effectiveness. There is a need for a solution that combines the merits of both analog and digital domains without incurring additional cost and complexity.

Now a new option offers a way to achieve this balance: the ‘Simple Digital’ family of parts from Renesas, which fits between the spheres of true analog and full-featured digital power modules.

Simple power solution

The Simple Digital power module family bridges the gap between the analog and digital domains. Simple Digital power modules provide a similar design-in experience to an analog power module, while retaining the digital PMBus™ interface for telemetry and configuration during real-time operation. They offer the full benefits and flexibility of a digital control architecture, and can be fully configured via pin-strap settings as can traditional analog power products. A programmability option with pin-strap resistors provides for a plug-and-play solution.

The unprecedented ease of design with a real-time system-monitoring capability and control via the industry-standard PMBus interface makes the Simple Digital module a unique solution. Full power-supply telemetry, including data on the output voltage, output current, fault status and thermal management, is supported, which improves reliability and system uptime.

Customers can also use the PMBus interface to validate their designs without the inconvenience of switching resistors and capacitors every time a function needs to be adjusted or modified, reducing the development time and overall cost of implementation.

Simple to use

Simple Digital modules do away with RC time constants, which are used to set delay and ramp times in traditional analog controllers. They also use the telemetry available in digital controllers and provide the capability to monitor critical data for early fault detection, creating a more robust and reliable solution. Temperature monitoring can safeguard against thermal failures by identifying hot spots and improving the overall thermal management of the system.

Simple Digital power modules bypass digital programming by providing a comprehensive selection of resistor pin-straps for configuring the power module. The system designer simply needs to select a resistor to program features such as output voltage, frequency, input under-voltage lock-out, ramp times, and soft-start/stop, as well as sophisticated features such as voltage tracking, external clock synchronization and phase-spreading.

The PMBus interface for a Simple Digital power supply offers a huge advantage during the development phase by enabling the designer to rigorously test for various combinations of output voltages, switching frequency, ramp times, and soft-start/stop without the inconvenience of changing hardware. This reduces the time required for testing considerably, while simultaneously ensuring that design integrity is not compromised.

Simplifying applications

Renesas’ pin-strap-configurable step-down PMBus-compliant DC-DC power supply modules are suitable for various powertrain architectures, particularly for FPGAs, DSPs and microcontrollers which require a current input ranging between 25A and 70A at the point-of-load. The modules provide similar high power densities to those of a full digital module in multi-rail applications.

Because of these modules’ thermally-enhanced High Density Array (HDA) packaging technology, the need for cooling airflows or additional heat-sinking is eliminated, further reducing system cost and size.

The RAA210xxx Simple Digital module family simplifies configuration and control of Renesas’ digital power technology while offering an upgrade path to full PMBus configuration through the pin-compatible ISL827xM family.

The RAA210925 is a dual-channel module which can greatly enhance the support to various power architectures, particularly FPGAs, DSPs and microcontrollers. The RAA210925 complements Renesas’ single-channel offering, providing up to 25A per channel and providing high power density in multi-rail applications.

All digital power modules from Renesas are supported by the PowerNavigator™ GUI, which is a user-friendly tool to help support PMBus communication.


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