ISL68137-61P-EV1Z

Introducing 12 new digital multiphase controllers and a companion smart power stage, including the industry's first digital solution with an Adaptive Voltage Scaling Bus (AVSBus^™). Learn how these fully digital multiphase controller solutions can significantly speed up and simplify design time.

Related Resources

• ISL99227

Transcript

Intersil has a very rich history when it comes to digital power, having developed a wide range of products from digital point-of-load to multiphase controllers. Intersil released 12 new multiphase controllers in 2016. This are our first digital multiphase controllers with a smart power stages. It's a complete solution to address the need of any core processor in the marketplace.

The 12 products span a wide range of unique application solutions. Basically anything in the marketplace, whether it's telecom, datacom or data center, we can address those high-current needs with this multiphase solution. The family makes up a couple of different ranges like x86, Intel-based, ARM-based, or even general purpose using AVSBus solutions.

Multiphase is used when you need really high currents. Typically, we're running from a 12V input to those low-voltage outputs (1V, 0.9V) and you really want to have 300A, 400A of high current levels. Multiphase achieves this by splitting up the current into individual phases to balance itself from a thermal standpoint, give you better transmit response, and a smaller size.

The problem using one phase is you have really large inductor, your FETs start becoming oversized, so overall you end up with a lower efficiency, larger solution space and more expensive solution. For best performance it's actually better to have everything split up into different phases.

Some applications can drive as much as 450A currents. Why not just stack multiple controllers in parallel? Well, that's one approach where people have tried putting different controllers in parallel and trying to drive to one common output. The problem is with these modern processors is you're also doing transient slew rates of 1000A/µs. If you try to drive it in parallel, they become out of balance. One device tries to source 200A. The other one tries to sync 200A. They fight each other. So the idea is you have one controller that drives all these phases together, such that they're all balanced and in tune.

1000A/µs is really fast so how is it accomplished? This is the advantage of digital multiphase! We use a patented control scheme that we call Synthetic Current Control. We actively manage the current at each phase, cycle by cycle and at any slew rate, we make sure every inductor, every phase is balance perfectly and does not overshoot or ring. We can deliver the current when and where it's needed.

The industry uses voltage control today. Why are we able to use current control? Historically, no one uses current control because the problem is the noise. You have these really small duty cycles as you convert to these low output voltages. To be able to measure the current accurately in the noisy environment is extremely difficult. Even though it's the best control scheme, it's not practical. This is where digital is able to overcome those analog limitations. We use a technique called synthetic current control. We actually synthesize every current waveform internally in the chip. So we get an accurate, cycle-by-cycle waveform that has the full bandwidth, noise-free, and zero latency.

Well, there's always latency and propagation delay as you move through the loop, for instance, going through the smart power stage. But what our device does is great, because we control synthetic current waveforms, we control a PWM clock. We can account for those delays. So over on our loop, by having a predictive nature in our device, we can actually make sure that we have zero latency overall in the control waveform. This gives us very precise current positioning.

The advantage of this loop then is zero latency and very fast transient response. Now the benefit of that is we can use less capacitance than any other solution in the marketplace. For these high-current rails, it's not uncommon to see 30% less capacitance translating into a smaller solution and lower BOM cost.

We released the ISL99227 which is a 60A smart power stage. Now, what that means is traditionally with multiphase controllers, you had external drivers and discrete MOSFETs. A power stage integrates all of those. What makes it smart is the fact that we now have current sensing and temperature sensing. So when you used to have to measure DCR, or even inductor to get your current information, we now have a differential signal going back to our controller that's accurately calibrated over line, load, and temperature, so we always know exactly the current per phase.

The smart power stage eliminates complex DCR networks and simplifies the design. You eliminate those RC components around the DCR, you've eliminated the mismatch and any of the errors that's introduced, and you've even removed one of those biggest noise sources. That phase node no longer couples in directly to that current waveform.

In our next video, we will show you the evaluation board and power navigator software.

This webinar introduces the ISL6812x and ISL6813x family of digital multiphase controllers targeting infrastructure power applications. This family of devices supports the latest PMBus 1.3 specification with adaptive voltage scaling bus (AVSBus).

Transcript

Powering Next Generation Cores - ISL6812x/ISL6813x Overview

In this presentation, I will be introducing the ISL6812x and ISL6813x family of digital multiphase controllers targeting infrastructure power applications. This family of devices supports the latest PMBus 1.3 specification.

Powering Infrastructure

We have an expanding portfolio of power products, including a complete family of both analog and digital power modules to make it easier for customers to take advantage of the latest advances in power management in their systems. With the launch of our digital multiphase controllers, Intersil offers a full market solution for any processor, SOC, graphics card, and FPGA in the market, backed by a full portfolio of point-of-load and other power management building blocks, which includes DrMOS and Smart Power Stages (SPS).

The latest generation multiphase controllers feature a full digital compensator. This offers power designers unprecedented design flexibility with no external compensation, as device tuning is all managed digitally using our powerful and intuitive PowerNavigator software.

By leveraging Intersil's innovative synthetic current control architecture, the user can quickly realize a complete power solution in under 30 minutes vs. spending days managing complex RC Tables when using competing analog control solutions in the market.

In this presentation, we'll run through the differentiating features of this exciting new family or products, discuss target applications, and showcase the available design materials and collateral.

Benefits of Digital Multiphase

A digital multiphase controller provides an improved system with greater performance and optimization vs. traditional competing analog controller solutions in the market.

Due to the nature of being a full digital implementation, all the device level tuning and configuration is achieved in software using the PowerNavigator software. The highly flexible digital design enables fastest time to market, as an entire power solution can be realized in minutes vs. spending days managing complex RC tables and board re-work.

Power density is increased thanks to the on-chip NVM, non volatile memory, for storing user configuration settings. The Intersil digital multiphase controllers can store up to eight unique configuration settings per device. This allows end users to make changes as needed for deployed systems without recalling back to swap out controllers or hardware.

With full telemetry supported, which includes features like current information per phase, realizing full system control and monitoring has never been easier. Additionally, the power engineer can take advantage of Intersil's unique digital current modulator, which supports lossless input current sensing. This further simplifies the design and minimizes BOM content at the system level.

At the heart of our control loop is our patented synthetic current modulator. In the next few slides we will review the underlying benefits of Intersil's full digital implementation, which leads to fastest transient response and lowest output capacitance vs. the competition.

Digital Multiphase: Complete Solution

The ISL99227 Smart Power Stage consists of integrated drivers and power MOSFETs, and includes integrated differential current and temperature reporting. This eliminates complex DCR sensing networks in the system and achieves a compact design. With multiple interface options supported, a power designer can realize a full system solution anywhere between one phase and 14 phases by leveraging Intersil's full portfolio of power stages and phase doublers.

With full configuration achieved using the PowerNavigator GUI software, the Intersil digital multiphase regulator is able to meet the needs of any modern microprocessor, ASIC, SOC or FPGA design.

ISL681xx Technical Highlights

In the next section, we'll cover the technical highlights of the ISL681xx family of digital multiphase controllers.

ISL681xx Digital Multiphase Controller Block Diagram

This is a platform overview of our family of new generation multiphase controllers. It features a fully digital linear current modulator with up to two outputs, namely X and Y. Two different device configuration options are available, up to seven phases across two outputs in a 48-pin 6mm x 6mm package, and up to four phases across two outputs in a compact 40-pin 5mm x 5mm package.

At the heart of this family of digital multiphase controllers is our patented synthetic current modulation technology. We use the synthetic current that is generated cycle-by-cycle for high frequency current balancing and to support the fastest transient response vs. any competing solution in the market.

With only synthetic current entering the loop, the user can realize a noise-free, full bandwidth linear loop using our digital modulator technology to achieve fastest transient response. Competing current mode enabled solutions rely on a second current loop to support current balancing, which adds latency in the design and subsequently impacts transient response time.

The full digital compensator enables adaptive "on-the fly" loop tuning using the PowerNavigator software, therefore eliminating external RC components typically found in competing designs. With on-chip NVM, the user has the option to store up to eight different device configurations, each accessible via a pin strap resistor.

The full digital controller family of products supports a comprehensive telemetry and fault management system to enable highly reliable designs. Features such as a Black Box to record full telemetry and fault status bits during a catastrophic shutdown enable a user to quickly troubleshoot a deployed system.

The controller family supports the full industrial temperature range, and supports all major standard interfaces to power any microprocessor, SOC or FPGA solution in the marketplace, and is complemented by our growing portfolio of power stages like the ISL99227, which is a 60A Smart Power Stage with integrated current and temperature sense.

Target Applications for Infrastructure Power

Shown here are the target applications for the infrastructure power products. These controllers are targeted at anyone who is using an FPGA, ASIC or network processor. Example vendors include Xilinx, Altera, Broadcom, IBM, Qualcomm, and Cavium. As far as end-market applications, both controllers make excellent fits in wired infrastructure applications, including routers and switches; wireless infrastructure applications, including basestations; and datacenter driven applications like servers and storage.

Digital Multiphase Design Benefits: Flexibility

The multiphase controllers support the latest PMBus 1.3 specifications, this includes AVSBus, known as adaptive voltage scaling bus. The AVSBus is an "open standard" defined by the System Management Interface Forum, for the purpose of adaptive voltage scaling for Non-x86 processor solutions.

The Intersil multiphase controller family offers unprecedented design flexibility, due to the nature of being a full digital implementation. The user has the ability to configure outputs and assign any number of phases across both or single outputs. The truth table on this slide captures just some of the different permutations of phase assignments that are available with this full digital implementation. For example, depending on the power solution need, a user could adopt a 4-phase controller and assign all phases to a single output, namely 4+0, or spread phase assignment in any combination up to four phases across both outputs, all configurable using PowerNavigator software and with zero external components.

Software Defined Everything!

Shown here are example screen shots taken from our PowerNavigator software used to configure and tune the device. Full device configuration is achieved in the software. The controller supports autonomous phase shedding, with adjustable current thresholds, all managed in software. This gives the user complete autonomy to adjust current thresholds to deliver maximum efficiency on their individual board design.

The full digital compensator enables on-the-fly loop tuning. The family of controllers, supports a dual-edge modulation scheme, which implies the controller can modulate both leading and trailing edges of the PWM pulse to respond to any transient event. Additional control knobs are available using PowerNavigator to filter out any noise and even pull in the pulse, with features like pulse advance to respond to a demanding load or transient event.

The variable duty cycle coupled with variable frequency of our digital modulator scheme and synthetic current control architecture enables us to respond to any load transient with precise voltage and current positioning. In short, with just seven simple screens using the PowerNavigator software, a user can realize a complete power solution in minutes and eliminate board re-work associated with managing complex RC tables that is evident in competing solutions in the market today.

Synthetic Current Control Loop

Shown here is the synthetic current control loop diagram unique to Intersil. On the left side is the voltage loop, which supports a front-end ADC. This enables all the loop tuning to take place in the digital domain. The feature that differentiates our controller loop solution vs. all competing solutions in the market is the implementation of synthetic current on a per phase basis. This patented design ensures a single linear feedback loop that is inherently current controlled.

The implementation of a full digital linear loop with zero latency offers tremendous benefits, which includes a noise free, full bandwidth solution delivering fastest transient response. The zero latency loop response, unique to Intersil only, enables power designers to realize lowest total cost of ownership benefits by supporting the lowest output capacitance for any power design.

Synthetic current supports cycle-by-cycle calibration and corrects for removal of error due to component aging and thermal. This ensures precise delivery of voltage and current across the full load. Moreover, with only synthetic current entering the loop and implemented on a per phase basis, this allows robust current sharing per phase. So regardless of the load condition, the phase currents are always balanced.

Synthetic Current Control Loop Advantages

In summary, Intersil's synthetic current control loop architecture implemented on the new generation multiphase controllers offers significant benefits vs. competing solutions.

The linear control loop implementation offers a noise free, full bandwidth implementation with one third lower output capacitance vs the competition. This not only delivers total cost of ownership savings, but offers substantial PCB savings, which is becoming a critical factor in modern space-constrained power designs.

The full digital implementation enables full device configuration and on-the-fly tuning, achieved using the intuitive PowerNavigator GUI design. Leveraging sophisticated control of the loop in software speeds up time to market and eliminates board re-work associated with competing solutions in the marketplace.

Digital Multiphase: Black Box Capability

Black Box is a unique feature available on these controllers. When enabled using the PowerNavigator GUI software, it supports extensive fault logging and captures full telemetry data in the event of a catastrophic shutdown. Black Box, when implemented in fully deployed systems, can help reduce system down-time by aiding the user in troubleshooting the chain of events that caused the entire system to shutdown.

Through PowerNavigator software, the user can implement the Black Box feature either through RAM or NVM. Both options capture full telemetry and fault status information in the event of a shutdown.

Digital Multiphase: Power Density

Intersil's digital multiphase controllers supports OTP or one time programmable NVM memory to store user configuration settings. The family of devices supports up to 8 NVM slots.

It is important to recognize that once an NVM slot is used, it cannot be erased or reprogrammed. Moreover, multiple versions of the same Configuration ID can be stored in NVM; however, the controller will always load the most recent version of the configuration.

At start-up, an external pin strap resistor is used to tell the controller, which Configuration ID to load. The released datasheets contain information on pin strap resistors available for the eight slots.

Example Configuration Stores

This slide illustrates how Configuration IDs are accessed during startup. In this example, two Config IDs are stored in OTP. Namely Config ID 1 and Config ID 4.

A 4+0 design is stored as "Config ID 1" using an 1800Ω pin strap resistor. Moreover, the 4+0 design is then updated, resulting in a new Config ID 1 store. Finally, a 3+1 design configuration is stored in Config ID 3 using a 3300Ω pin strap resistor.

As you can see in the memory allocation diagram in the middle, three OTP slots have been used. Moreover, it is important to recognize that during startup only the latest Config ID 1 value will be loaded if an 1800Ω pin strap resistor is used. Subsequently, a 3300Ω resistor would load the configuration stored in Config ID 4.

Intersil Smart Power Stage Overview

Intersil has developed a full range of power stages supporting various current ratings to meet any ASIC, SOC, FPGA, or graphic card power rail requirements. When designing with Intersil's multiphase controllers, the ISL99227 60A Smart Power Stage is an excellent co-sell opportunity.

Unlike competing solutions that support a 20V lateral FET process that pose a reliability risk, especially in key server and telecom applications, the ISL99227 Smart Power Stage supports a 25V trench FET design to deliver excellent immunity to voltage spikes and mitigate avalanche conditions.

The large Copper pads for GND and Vin result in low thermal resistance vs. competing monolithic designs that support flip chip on lead packages. The dual side cooling package coupled in a proprietary 5mm x 5mm package, designed to minimize packaging parasitics, deliver excellent efficiency across the full load, thus making it ideal for high current applications such as servers and infrastructure power.

With integrated current and temperature sense reporting, with 3% accuracy over line, load and temperature, the ISL99227 simplifies the powertrain design by eliminating complex DCR networks and delivering an ultra-compact power solution for space constrained designs.

AVSBus Overview

In this next section, we will provide an overview on the AVSBus that is supported on the ISL68137 and ISL68134 family of devices. This is a key differentiating feature of the ISL681xx controllers.

What is AVBus?

As highlighted earlier in the presentation, AVSBus or adaptive voltage scaling bus is an extension of PMBus v1.3.

AVSBus is an "Open Power" standard devised by the System Management Interface Forum (SMIF) of which Intersil is a member. With Intel and AMD having their own high-speed interface to connect to their x86 processors, the power community developed AVSBus as a competing proprietary-free open standard to facilitate point-to-point communication between a host processor and a controller at up to a 50MHz bus speed.

AVSBus has now become the de facto standard across many OEM driven microprocessor and network processor designs. By taking advantage of the high-speed bus interface, OEMs can now deliver power efficient processor solutions in the marketplace and minimize wasted energy associated with propagation delays, as illustrated in this slide when using a standard PMBus approach.

Intersil is a market leader with the AVSBus implementation available on the ISL68137 and ISL68134 controllers. As such, the Intersil solution has been implemented exclusively in several reference designs across multiple OEMs, spanning server and network processor designs.

Digital Multiphase Product Matrix

This slide captures the product matrix for infrastructure power products. The ISL68134 and ISL68137 are two controllers available that support AVSBus. The ISL68127 and ISL68124 controllers, support latest PMBus v1.3 specification. All controllers captured in this table support dual outputs and phase assignments are fully configurable using PowerNavigator software.

Example Application FPGA Rails

This design example showcases how the Intersil family of digital power products fits in a Xilinx, Kintex or Virtex class FPGA design. For the high current core rail, Intersil offers digital multiphase controllers that make it an excellent fit. For the other FPGA auxiliary rails, DDR4 memory rails, and system level 3.3V and 5V rails, the ISL68200/01 are excellent solutions.

Development Tools

This next section covers development tools available for our controller family.

Digital Multiphase Development Platform Overview

Intersil has developed a broad range of evaluation boards to facilitate both PMBus and AVSBus testing across both 4-phase and 7-phase controllers.

Development Board Example

Shown here is an example AVSBus evaluation board supporting a 3+1 configuration. All boards are fully compatible with PowerNavigator software and include a built-in load hitter to facilitate transient testing. As shown in the picture, all AVSBus boards come with a PMBus and AVSBus dongle. The AVSBus dongle is used to facilitate AVS testing. All boards including the one shown support ATX supply or separate 12V and 5V bench supply connectivity.

ISL6812x/ISL6813x Collateral

Full AVSBus and PMBus datasheets are available online. Evaluation boards are available for purchase for both up to 4-phase and up to 7-phase controllers, and include the USB to PMBus adapter and USB to AVSBus adapter. Download the PowerNavigator software from our website. All the controllers are offered in bulk and reel options.

Introducing PowerNavigator v5.3.45 and its integration of the latest family of digital power multiphase controllers. In this demonstration, we will be using the ISL68137 7-phase digital multiphase controller.

Transcript

This video introduces PowerNavigator™ GUI Software and its integration with our latest family of digital power multiphase controllers. PowerNavigator is Renesas' GUI for use of all of our digital power controllers. It's used to configure, set up, read back real time telemetry, and also debug systems on real time.

For today's demonstration, we will be using the ISL68137 7-phase digital multiphase controller. Here we have the evaluation board. It's powered by a 12V and 5V vent supply. We also have PMBus and AVSBus connectors that go to the PC in an alternate interface with our PowerNavigator software.

So looking at PowerNavigator, the first thing you'll see is the power map. The power map gives a system-level view of all the products that are connected to the GUI. Here is the ISL68137. It's a dual output device, so we have two blocks on the power map. One block has all seven phases assigned to it. This is highlighted by the seven green dots inside that rail block.

On the right hand side, we have our monitor view. Monitor view shows the output voltage, the input voltage, the load current—all telemetry from the device in real time.

Double-clicking on the rail block brings up the rail inspector design tool. Rail inspector is how we configure the device. It has the rail name, its status, and on the left hand side is a menu. As I walk through the menu, I'm able to fully configure all of the features inside this product.

The first screen we'll look at is called phase configuration. Phase configuration allows me to assign each one of these phases to one of the two control loops inside the device. On this particular board, I have seven phases assigned to loop 1. It also allows us to enable auto-phase dropping for efficiency. When auto-phase dropping is enabled, as the load current changes, we automatically add or take away phases. The thresholds for auto-phase drop are all configured digitally and done so on the screen.

The next page is a general configuration page. This does the outward voltage settings, including the fault limits, as well as the switching frequency.

The power train page is used to set up the power train for this device. You input the MOSFET properties, the inductor that you're using, the output capacitance and its properties.

We also set up a current sense gain. This eval board uses our smart power stage which automatically provides current sense information back to the controller, making current sense very easy to set up.

The next page is the transient setup page. The transient setup page is where you configure the digital control loop inside this device. It's used to set up the control loop gains, AC current feedback, and then additional things like pulse advance and load line settling to improve the low transient response. If you're using R load line, the droop impedance is set in the R droop box.

The next screen is diode braking. Diode braking is used to improve the transient response by turning off the load-side MOSFET during a load release. This can reduce the overshoot of the output voltage, improving the overall response of the controller. Ramp time is used to set the on delays, the off delays, as well as the rise and fall times of the controller.

The final screen here in the general loop configuration is the temperature sense setup. This enables an external diode or the TMON output from the smart power stage, where the controller can measure the real-time temperature of the smart power stage.

Moving on to the faults section, all the faults in this device are configured digitally. So the fault responses and fault thresholds all are configured with this GUI, making the responses in the setup threshold very easy to set. We have voltage, current, and temperature faults. They're all configured with the GUI.

The final thing is a black box. Black box is used to automatically trigger black box capture, in the case of a fault. When enabled and a fault happens, the controller captures all the telemetry information and saves that to the device. This can be used for debug later on and as way to tell exactly why a controller shut down.

Once the device is fully configured, you have the memory configuration page. Inside the device, there are eight different configuration IDs that allow you to save up to eight unique settings inside these controllers. Once you're done configuring, you would simply hit save, and that would save that setting to one of these eight slots inside the device's non-volatile memory.

The real inspector tool also has advanced features like AVSBus. AVSBus is a fast point-to-point communication with up to 50MHz speed. This allows the part to communicate with A6 as support AVSBus interfaces in a very fast manner. With PowerNavigator, you can very quickly evaluate and demonstrate AVSBus and see if the dynamic response behavior of the controller within oscilloscope.

The final page here is the telemetry page. Telemetry allows you to plot real-time telemetry of the device. This includes input voltage, output voltage, current, etc., all plotted in real time, as we've shown here.

We hope this video was helpful in explaining how the PowerNavigator software interfaces with our full digital multiphase controllers.

Learn about the full digital control loop and how easy it is to tune using the PowerNavigator GUI software. The patented Renesas synthetic current control technology achieves the industry's fasted transient response.

Related Resources

• ISL68137-61P-EV1Z
• ISL68137

Transcript

This video highlights the full digital control loop in our latest generation, multiphase products. Renesas' multiphase products have a control loop called synthetic current control. It's a full digital control loop that's very easy to tune.

We are using the ISL68137 evaluation board to demonstrate. The eval board has a controller as well as our smart power stages. On the eval board is a 100A low transient generator with a DIDT of 100A/µs. On the oscilloscope, we have the output voltage, the load step, and two of the six PWM signals driving the power stage. With our default configurations, the output voltage is within plus minus 4% of the 1V set point.

Using the PowerNavigator^™ GUI software, we will show how easy it is to dial in and improve the transient response with the synthetic current control loop. Moving to PowerNavigator, the first thing we'll show is increasing the gain of the control loop. There's a proportional gain term by increasing it with the GUI, and then going back to the transient response, you can see now, we've reduced the peak-to-peak deviation to plus minus 3%.

The next feature we'll show is called pulse advance. Pulse advance allows us to temporarily speed up the switching frequency during a load step. Currently, pulse advance is disabled. As we enable it and turn up the pulse advance gain, you can see now that the load step, the output voltage deviation is down to 2%.

On the load release side, synthetic current control has a feature called diode breaking. Diode breaking turns on the low-side MOSFET during a load release to improve the output voltage deviation during the load release. We'll go ahead and enable that. Now the output voltage deviation has decreased to plus 2%.

That wraps up our demonstration of synthetic current control. With Renesas' PowerNavigator GUI software, full digital control loop, and latest digital multiphase products, tuning the transient response for any type of load step is now very simple.