Taking a new direction with analog

Interviews |
By eeNews Europe

Microchip’s MCP19111 single chip mixed-signal solution has integrated an analog-based PWM controller with a fully functional Flash-based microcontroller to offer design engineers the flexibility of a digital solution with the speed, performance and resolution of an analog-based controller.

"Although Microchip is best known for microcontrollers we do have a significant analog group," explained Stella. "Microchip is known for being profitable.  After all we have achieved 88 quarters of consecutive profitability.  The Analog division has helped that profitability and started around the 2000/2001 period when we acquired a company by the name of Telcom Semiconductor that gave us a fundamental start to our analog portfolio.  The Analog business has grown steadily since 2001 but in the last two years we have seen a significant growth in analog revenues".

There are currently 28 product lines within Microchip’s analog portfolio which cover a wide array of analog-type peripheral devices that surround the microcontroller.  The company now has more than 830 products in the Analog business portfolio and the number is growing rapidly.    

Stephen Stella,

Microchip’s Product Marketing Manager Analog & Interface Products

"The key ones in our linear group include a very broad array of operational amplifiers that are used in sensor-type applications," explained Stella.  "However, power management is becoming a key investment area for Microchip."       

"Seeing this growth Microchip’s leadership team has continued to invest in analog technology and analog design and the outcome of which are new products like the digitally enhanced power analog controller and the new processes that we are developing".     

Stella continued: "Microchip’s standard analog strategy has been historically supporting the microcontrollers business.  As the Microchip microcontrollers are designed in there are a lot of components that go in around them to enable the microcontroller in the application.  Historically our analog strategy has been to attach ourselves to the microcontroller be it as amplifiers or ADCs or LED drivers or power MOSFET drivers.  What the analog development team does is to enable the microcontroller to do what it needs to do in a particular application.  We are now expanding the scope of that strategy not just to Microchip microcontroller type applications but also to stand-alone full analog applications".       

"We recognize that there is an integration path on the microcontroller side where a lot of the simplistic analog capabilities are being pulled into the microcontroller.  Even though the requirements intensify it still makes sense to do things outside the microcontroller.  If you look at an A-to-D conversion then it is clear that for some 24-bit super high-speed A-to-D converter the process technology needed to handle that does not necessarily match up to the process technology needed to support an 8-bit micro.  Most of Microchip’s 8-bit business is in simple embedded controllers".       

"At least 90 percent of our products are for one-stop shopping," suggested Stella. "Microchip has not historically been an innovation leader in the analog space.  In the past the developments have been really to supplement the microcontrollers that we have. But now we are starting to do new and interesting things that no one else is doing. As we take those enabling technologies we are starting to focus more on six core application areas".     

The core application areas are:      

  1. Power and flow metering (which relates to power monitoring and energy metering)
  2. Smoke and carbon monoxide detectors  
  3. PC/laptops/servers and gaming  
  4. Consumer type devices
  5. Temperature measurement
  6. Power supplies.      

"Each one of these applications is a power management sub-application," explained Stella.  "All of them use and need power management type devices and all of them have unique requirements.  We have recognized this and have started to put applications support behind them to leverage all of the strengths and capabilities and products within Microchip to develop valuable solutions for our customers.”     

"There is an application need for Microchip to support higher voltage technologies," advised Stella.  "We want to start building that into our portfolio.  That has opened us up to some higher power applications so we went to driving higher current and that made us look at how we should support higher current applications.  And as you extend into even higher power applications then efficiency becomes more and more of a key factor.  So we need to look at how we can make solutions that enable our customers to achieve higher efficiency in their target applications".     

“The high level application areas being addressed by the new digitally enhanced power analog controller will focus on computing, consumer and communication,” explained Stella.  “These are DC-to-DC point-of-load type of applications.  Microchip has its dsPIC device on the digital serial controller side which handle power levels of 300 W and above whereas our analog portfolio is handling 50 W and below.  But the new digitally enhanced power analog controller focuses on an intermediate area which is some place between 50 W and 150 W.”     

“Over the past two or three years we have seen an introduction of a hybrid control-type topology or mixed-signal-type topology where there is a component of analog and there is a component of digital.  There are different ways of developing these kinds of solutions.  We are seeing on the microcontroller side continued integration of analog-type peripherals whereas on the digital side it is a little bit more difficult to integrate technologies because of process differences.  What we saw as an opportunity was a digitally enhanced power analog controller”.


(Click on image to enlarge)

“We have retained the performance of the analog control without introducing the need for a high-speed, high-performance microcontroller. That typically means a very small lithography type process which is less expensive. The same thing applies with the analog-to-digital conversion element. The solution needs to be high precision for load regulation accuracy and it also needs to be high speed for the same bandwidth concerns that you have if you try to convert it into a digital domain. So you eliminate cost and you eliminate complexity.  And when you eliminate that complexity it also enables some additional integration on the analog side”.     

Stella continued: “Yet it still offers digital flexibility because with the small microcontroller you can actively optimize the analog. That allows you to offer ‘configurable analog’ solutions which is something new because you don’t normally hear the words ‘configurable’ and ‘analog’ in the same sentence”.  "Essentially we have the 8-bit MCU while also having the analog controller with an integrated MOSFET driver and an integrated LDO. 

The device offers the fully programmable MCU core which enables the custom IP integration that customers tell us they are looking for and allows them to do custom firmware development ".     

“This device is more than just a controller it can turn into a system architecture power management device because it can now be used to control the turn on of various voltage regulators within a system.  With load complexity increasing and with advanced devices like FPGAs requiring certain timing sequences and voltage rail performance you can now have a central device that could help you sequence your power management needs”.

Improving space utilization

"The digitally enhanced power analog controller solution is packaged on a monolithic chip in a 5 x 5 mm QFN package.  From a device standpoint this is as small or smaller than any similar competitive devices but I have not seen any hybrid type devices that allow custom IP code support which is why this is an industry first," said Stella.  "Customers told us that they had an interest in integrating their own IP to this device".

“Size of a device does matter more and more,” suggested Stella. “Things are getting smaller and smaller.  If you think of it in terms of designing laptops then it would be much better to use that area on the MOSFET side to achieve easier heat dissipation.  We are not dissipating a lot of heat in this digitally enhanced power analog controller device”. 

“The drivers are what defines the size of the power rating,” explained Stella.  “These drivers are sized for 2 A on the high side and 4 A on the low side that makes them good for a 40 A or 50 A powertrain. The heat generation is very low because even though it might be 2 A or 4 A source you do not need a heatsink here and so you do not need a large footprint. The MOSFETS is where it is going to get warm.  The design engineer is going to need to pay particular attention to his or her MOSFET layout and how they are cooling the MOSFETs”.


System solutions and power management  

“Microchip recognizes that our customers are not just going to use our digitally enhanced power analog controller device by itself,” advised Stella. 
“From a system solution standpoint, heat is obviously a key factor.   Designers will need power MOSFETs to convert the actual power. In 2012 Microchip announced that the company was planning to develop its own power MOSFETs and now we will be expanding that family by an additional four devices and one of them is the lowest RDS(on) device that Microchip now manufactures”.

"The power MOSFETs are not general purpose devices," explained Stella. "Microchip has no desire to be a general purpose MOSFET supplier.  We are not going to be a full service MOSFET supplier.  We are mainly focused on power supply and power conversion applications.  The key here is that there is a link between the controller and the MOSFET."     

"The MOSFET decision allows us to better understand the technology and the places we can tweak and tune to ultimately develop a stronger overall power conversion system."     

"So we are looking for ways to leverage this technology to improve the performance of the power conversion circuit be it in terms of efficiency or transient response, robustness or  whatever individual value drivers our customers are looking for," continued Stella. "The combination of mid-voltage Flash-based flexible controller with these high-performance MOSFET devices puts Microchip in a one stop shop position while offering valuable solutions to our customers. The new solution enables engineers to re-think their solutions and potentially leverage any value that they identify".       

"Most of our MOSFET competitors are coming at the market from a different angle.  Historically they have been in this area longer.  Maybe they struggle on the controller side which is where Microchip is particularly strong but what we are seeing is a strong integration trend which allows Microchip to control its own destiny".


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