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  • Hello my name is Andy Reiter, I'm with Microchips Power Supply Applications Group.

  • The topic we would cover today is our new CIP Hybrid Power Starter Kit.

  • This starter kit is introducing the PIC16F176X and 7X families of freely

  • programmable pwm microcontrollers. These microcontrollers

  • have specific peripherals that are running independently from the core and

  • are highly configurable so that it can configure them or interconnect them in

  • specific ways to form some PWM controller architectures. So the

  • advantage of this freely configurable peripherals are that you can tailor the

  • PWM controller capabilities specifically to your very application. To allow

  • designers to utilize these capabilities we also have introduced a new design

  • tool chain, which is encapsulated in our development environment MPLAB X. So this

  • is part of our Microchip Code Configurator tool called MCC, and is a

  • set of sub libraries that allows you to simplify the configuration of multiple

  • peripherals at the same time. We have set up this assembly in this demo here where

  • we have a starter kit on the left and here on the right on the screen you see

  • this MPLAB X environment with the specific switch mode power supply library

  • subset for Microchips Code Configurator. So this tool now can be used to set up

  • PWM controllers that support different control modes like peak current load

  • control, voltage mode control, average motor control. You can combine

  • multiple control loops, you can add in specific fault handlers and the device

  • itself then supports you with setting specific thresholds like shutdown levels

  • for maximum currents, voltage clamping, inputs under voltage

  • over voltage lockout and further features by utilizing the internal DACs.

  • So the variety of things you can do with these peripherals is really really wide.

  • So the switching power supply library helps you to abstract the

  • capabilities and tailor them to specific topologies. So therefore we also offer

  • different sets of pre-configurations for targeting specific topologies. So once

  • you have used that tool to set up a PWM controller for a specific application

  • and topology, that where you're generating the code, the code is

  • downloaded into the device, the codes that's generated with the device also

  • includes functional aspects like soft start, so that you're having a nice

  • behavior right from the beginning, so that when you fire up the power supply

  • for the very first time that you can be sure that it won't burn. So once you have

  • downloaded it, and this is what we are doing in this demo set, is then we have

  • connected a network analyzer to the output, we are injecting an error signal

  • and we're using our BODI 100 Network Analyzer to measure the total open-loop

  • gain in the closed-loop system. So depending on the additional tools you

  • might have used to design your power supply and to set up your compensation networks,

  • so to achieve a certain stability of your application, you can then

  • just measure directly from the kit the final results compared with your

  • simulation and then you take it from there and in further some iteration

  • steps you might have quickly achieved your goal.

  • so before we go into the details about this kit and its software and design

  • tool chain might be necessary to explain a little bit what hybrid power actually

  • means the work hybrid is often used in different contexts like hybrid power

  • supplies is something entirely different from hybrid power controllers so hybrid

  • in our context means that it's a device which is somewhere between the analog

  • control domain and the full digital control domain so analog controllers

  • usually come as fixed Asics covering very specific topologies or specific

  • applications so the conventional pol controllers for example or you have here

  • switch switching regulator for flight controllers or resonant converters and

  • for every single one of them so for every single application you might have

  • a set of specific Asics to choose from while full digital control then

  • digitizes even the feedback loop so everything is running and software the

  • interface is an A to D converter so analog signals continuous time domain

  • analog signals are converted into digital signals and then processed

  • through software and then some PWM is adjusted so this the letter 1 full

  • digital control gives you extreme flexibility in terms of what a

  • controller can do while analog circuitry is might have a significantly higher

  • performance but they are nailed to what they have been designed for so that

  • section between both worlds that is what we're trying to cover with hybrid

  • controls so it means we have a small device with relatively low power

  • consumption but and in within the architecture we're combining digital

  • logic with analog circuits so that we can leverage that in the advantages of

  • both worlds in one single device so and when we are focusing on these hybrid

  • devices then it's always a a device which is targeting the

  • application would have a specific requirement for very specific features

  • so the basic concept of these products is that in one chip you get a

  • microcontroller core and a PWM controller peripheral that PWM

  • controller peripheral always breaks down into three main major blocks consisting

  • of the compensator so Erin play fire basically and the modulator so the

  • modulator then determines which control loop control mode you're applying and

  • there's always an additional fault level that helps you to make sure that the

  • power supply stays within its safe operating range default is usually tied

  • into the modulator or uses inputs to the modulator to shut down the passerby in

  • case something is going wrong so when we're looking into the modulator so here

  • on the right side we see a specific setup for a voltage or an average

  • current mode and on the top we see an implementation for a classical picker

  • remote controller so here on the upper writes in the current note section we

  • find a subset of codes lay or labeled with PRG so that stands for programmable

  • RAM generator so we are utilizing this ramp generator to generate a negative

  • ramp which is modulated onto the reference input to our modulator that

  • then is used usually in Picard mode for slope computation but it can also be

  • used in voltage mode this is when you look below you also see a voltage range

  • on the upper right where we use a positive ramp to generate an analog PWM

  • signal the next therefore we find in this modulator are fast comparators so

  • in the current mode section on the top we find that comparative

  • between the RAM generator and our so-called Co G which is actually our PWM

  • output logic block so that comparator is used to tie in the current feedback so

  • that we can trip on peaks of the inductor current while in voltage and

  • average card mode that comes very same comparator is now used to compare the

  • reference from the Aaron profile to the artificially generated ramp and when the

  • ramp exceeds the reference voltage level then it changes its output strips and

  • and it's our latch and this then influences our PWM output so in both

  • motivators we always use a PWM module and the so called CEO cheese or the

  • complimentary output generator or in other devices it's called

  • a complimentary waveform generator cwg but these blocks to is actually said

  • they give to get to the capability to start out from a single PWM signal and

  • split it up into complementary waveforms allowing you to adjust that x or you can

  • split it up up to a full bridge drive so it also offers additional inputs for

  • false signals so fault triggers that come from different peripherals or from

  • external circuits can also be fed into the PWM logic and some additional glue

  • logics and also would allow you to establish something like conditional

  • fault handing so the third level is the compensator the compensator on these

  • devices usually just a are just consisting of an errand to fire so this

  • is actually a general-purpose operational amplifier then you get a

  • deck to adjust reference and then the reference itself which is called the

  • fixed voltage reference F we are

  • so in addition to help you to condition signals for especially false signals of

  • to define fault levels to trip on there is a an additional set of comparators

  • and attack with a lower resolution so usually you get five bit tags that help

  • you to set up thresholds that five bits might not be sufficient for in some

  • cases so when you need a higher resolution then it is possible to use

  • external resistors to create a window which is then still scalable with five

  • bit and then you send it around a threshold range you would like to set up

  • so once we have picked these three blocks we now can use these to set up an

  • entire analog feedback loop here we see the first architecture so on the right

  • we have a power supply so in this case it's just for the purposes of a sake of

  • an example it's a boost converter that offers a voltage feedback coming from a

  • voltage divider and we have a peak current signal which is taken from below

  • the boost mains which using a shunt resistor so the voltage feedback now is

  • fed into the outer loop portion of our architecture which is then our air

  • amplifier so the amplifier compares that signal to our reference which is

  • internally set by attack the output of that amplifier is fed into the

  • programmable Ram generator and this part we are modulating a negative frame onto

  • this reference voltage to apply a slope compensation for our inner p-card load

  • control loop then we are entering then or we are taking this output of this

  • program of a ramp generator feed it into a comparator that comparator compares

  • that reference signal to the peak current signal that's coming from our

  • shunt resistor and then that output of that comparator trips our

  • PWM output logic and effectively true hates the duty cycle so to set up the

  • switching frequency we are now using a digital PWM oniel which allows us to set

  • up a fixed period with a maximum duty cycle so in case the comparator does not

  • trip the pwm module in time it's the only time base of the pwm module which

  • makes sure that the duty cycle is not hitting hundred percent and maybe with a

  • bad outcome when your inductor saturates and then your power supplies effectively

  • going out of control

  • so one thing we see here in this particular example is because of these

  • devices are highly configurable and can practically drive any kind of topology

  • it is very hard to define our C Network values that might be necessary to set up

  • an appropriate computation for every single different topology out there so

  • therefore all of the compensation networks need to be external with these

  • devices so we see here in the lower around the OPA so the operational

  • amplifier that the input as well as it's the output is connected to a device pin

  • so these device pins are usually sitting right next to each other so that it's

  • very easy that it can place your RC components of the conversation that are

  • very close to the device so after having established this basic feedback loop we

  • are now adding the fault level so the fault level consists of a comparator

  • with five attack in this case we are using it as an additional over current

  • shut down and then we can feed that output of the comparator directly into

  • the CG so that it asynchronously overrides anything that's coming from

  • the software from the rest of the European architecture

  • and we can truncate the duty cycle and turn off the PWM immediately as fast as

  • possible so usually these comparators have a propagation delay of between 30

  • and 50 nanoseconds and this is the timeframe in which she can shut down can

  • you respond to fault and shut down the power supply economy so what we can do

  • with these PWM controllers now is a lot so as I said potentially you can support

  • all kind of different configurations for specific topologies it does not only

  • cover fixed frequency you can also setup the peripherals to support user 80

  • controls like internal time constant of time quasi resonant converters resonant

  • converters so the variety of possibilities is really really wide so

  • for just to keep things simple let's just start with fixed frequency

  • operation off a standard topology and this is what we are doing with this

  • starter kit so this starter kit we have used a simple synchronous buck converter

  • not only because it's safe to operate it easy to compensate but also because

  • everyone is very familiar with this topology so this starter kit now comes

  • with multiple options so that it can play an experiment and explore a little

  • bit the capabilities of the part play with different configurations and see

  • how you can solve different design challenges by using different

  • modifications of a preset of provided examples so when we are looking into the

  • hardware we find that this port is as a power supply on the lower side so this

  • is where we find our synchronous buck converter so that buck converter has

  • been designed for a power level of approximately 25 watts so the maximum

  • current call from the outputs at 3.3 volt is

  • roughly at around 8 m/s so you're above this is where we have find our

  • controller so that controller is bigger than it would be necessary for that

  • single topology so we have picked our superset device providing up to four

  • independent pwm controller peripheral sets the reason why we have done that is

  • to allow you to switch between different control modes so we have set up one PWM

  • control of the voltage mode another one for pico remote control in the third one

  • for average current mode control we use the peripherals of the fourth one to add

  • more advanced functions one of them for example is VCR sensing so one of the

  • current feedback options provided by the power plant is a RC network which is

  • tied in parallel to the main inductor and which can be used to to use a

  • lossless sensing technique which is fairly popular especially in low voltage

  • here will applications to implement that function we need an additional append so

  • as the op-amp is still available from the fourth PWM controller architecture

  • we can now utilize it to create an additional option which then is tied

  • into one of the other PDM controllers so that kit now is supported by the power

  • supply library NCC so when we are now trying to utilize

  • this extreme flexibility of the Percel we really rely on tools which try to

  • keep the complexity as low as possible during the design process so for that

  • particular purpose we have created this switching power supply library which is

  • available in the microchip code configurator

  • so the basic architecture so the ones of you who are familiar with MCC might know

  • that it is a graphical tool that helps you to configure specific settings of

  • one independent peripheral so usually when you set up an application you pick

  • one person like a UART and then you use that school to set up moderate or very

  • specific details of that very powerful and then you're generating hold and the

  • generated code is then called during startup of the device and putting that

  • function provided by the person in place so now as we have seen that a switchman

  • power supply controller is more than just one single peripheral the

  • configuration of multiple blocks can get very tricky so eventually you might end

  • up with seven to nine different peripheral blocks that need to be

  • connected in a very specific way to achieve a certain function so to

  • simplify that design process we have now added additional layers to our MCC

  • design tool so here on the bottom of that diagram we see that classical MCC

  • layer this is what most of you are maybe familiar with and this is what contains

  • all the different configuration sets of every single powerful so here in that

  • list you see all the peripherals that are used to form that function of a PWM

  • controller so here we find this program a program generator the complimentary

  • output output generator the PWM module a timer comparators digital to analog

  • converters fixed voltage references op amps and so forth so these blocks mell

  • are merged into that functional blocks of a modulator here on the left for peak

  • current mode control and compensator block which consists of an op-amp attack

  • and the fixed voltage reference here in the right we

  • another set and this is the model a box for voltage not control or average more

  • control so once you have you know which control mode you would like to use then

  • we can tie together compensator and model a the block to form a control mode

  • block in this case we have two options the card mode control or voltage or

  • average mode control now this block is still very generic and it's not really