EEWeb Pulse - Volume 24

Electrical Engineering Community

Brett FoxTouchstone Semiconductor, Inc.

EEWeb

PULSE EEWeb.comIssue 24

December 6, 2011

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TABLE O

F CO

NTEN

TSTABLE OF CONTENTS

Brett Fox 4Touchstone Semiconductor, Inc.

Featured Products

Software and Hardware Platform Enable 10Over One TeraFlop Processing RatesBY MICHAEL PARKER WITH ALTERA

System Perspective on Specifying 14Electronic Power Supplies:Load CharacterizationBY BOB STOWE WITH TRUE POWER RESEARCH

RTZ - Return to Zero Comic 17

An introduction to a processing platform that provides the advantages of both floating point and fixed point processing.

Interview with Brett Fox - President and CEO

Learn about the effect of the load when specifying a power supply.

8


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TERVIEWTouchstone Semiconductor, Inc.

How did Touchstone come about?The idea for this company has been floating around with me for many years, actually since I left Maxim in early 2000. Back then was not the right time to start a company like Touchstone. At the time, the funding was going toward businesses that were one-product, one-customer type models. VCs could make an investment and it could quickly turn into money. We were trying to build a real company. When I left Micrel

in 2005 I started to think about what I wanted to do. I was fortunate enough to know some people in venture capital. Crosslink Capital, a VC firm in San Francisco, asked me to be an Entrepreneur in Residence (EIR), which is a pretty cool job. You essentially are given a salary, an office, and a business card. You get to sit in on their meetings and see the inner workings of how a venture capital firm works. They will help you look at companies in your space, and if you want to start

a company, they will help you do that. The real genesis of Touchstone started there. I started to work on finding a team of people, flushing out the business plan more, making contacts and all those types of things. When I left Crosslink in early 2008, Touchstone was formed, and I started raising money in earnest.

What was the most challenging aspect of starting Touchstone?The most challenging thing was raising the money. It took us two years to raise our funding. We started in early 2008 and found the first investor, Opus Capital, within a month. Most people say if you can find one investor, you will find another one easily. In our particular case, because of the economic environment of 2008 combined with the environment of semiconductor investments (which continued to worsen throughout the year), we saw that it was unlikely we would close our funding in 2008. After 2008, we really had to regroup. Opus stood with us. In the summer of 2009, the economic environment was getting better; VCs were starting to put money to work. We

Brett Fox - President and CEO at Touchstone Semiconductor, Inc.

Brett Fox


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started to raise money in earnest again. In early fall, we found Khosla Ventures as our second investor. I am thrilled at how it worked out; we found two really good investors who know our space. Opus’ Managing Partner, Gill Cogan, was actually an original investor in Maxim, and when you look at our business model, we knew he would be a fantastic resource. Pierre Lamond led the deal for Khosla Ventures. Pierre is a co-founder of National Semiconductor and was involved with Linear Technology and many other successful semiconductor companies. He was very familiar with what we were doing, and was looking for a company like ours to invest in. Our funding (money in the bank) came on March 8, 2010, and since that time it has been a relatively straightforward ride for the company. I am not saying there have not been bumps along the way, because indeed there are always unforeseen things.

Can you tell us about the Founders of Touchstone Semiconductor, Inc.?All of us either come from Maxim, Linear, or Analog Devices. Most of the team has worked together in one way, shape, or form.

I have my BSEE from the University of California, San Diego, and my MBA from the University of Southern California. In 1989 I joined Maxim, and before that I was a designer for about five years. When I joined Maxim, it was a roughly $40 million company, and when I left in 2000, they were making over a billion dollars in revenue. I was very fortunate—right place, right time, and right set of skills. I ended

up setting the strategic direction for most areas of the company. After Maxim I worked at a start-up for about nine months. Then I went to Micrel for about four years and ran the high bandwidth division. I ended up turning that around from being the least profitable division of the company to the most profitable when I left. From there I went to Crosslink Capital for about a year, and then started working full time on Touchstone.

The thing that we really want customers to think about Touchstone is that

the company is doing cool and unique things. Hopefully, as time goes

on, we will achieve that reputation, and

customers will look to us for those types of cool

and unique products.

Jeroen Fonderie, the Vice President of Engineering, has a PhD from Delft University in the Netherlands. That is one of the best engineering schools for analog designers in Europe. When he was there he wrote a book on op amp design. He has written over 20 scientific publications, and he holds seven patents. Beyond

that, he is a fantastic manager, and a very good business man. In the Analog world, that is a very rare combination. When you put all three of those factors together, you have a great VP of Engineering for a company like Touchstone.

Adolfo Garcia, our VP of Marketing and Applications, started out also as a designer. He went from being in the design world to joining Analog Devices, and worked there for several years before moving on to Linear Technology and continuing in applications for several more years. He then worked at Micrel, which is where we crossed paths. He was running part of that business on the analog side. He then worked at a couple of other analog companies, and when I was looking to start Touchstone, he was the ideal guy to run marketing and applications. You want someone who is technically very strong and who can cover a lot of different products.

The design team is mostly from Maxim, Linear, Analog Devices, National, or MPS. All of the designers in the company have also worked together in some way, shape, or form. Some of the designers and I go back 20 years; they all average about 20 years of experience and about 10 patents per designer. So this is a group that can hit the ground running, can work independently, and will be able to get things done in a reasonable time period. We also wanted people that fit in our company culture, you want people that work well together. It does not mean that everyone has to be best friends or see eye to eye on every issue, but they have to be able to work well together and understand


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the focus of the company. Everyone here believes in our model and is moving forward to implement our strategy.

How do you choose the products to manufacture?We have two strategies we are working in parallel. The primary focus at the beginning was alternative source products. We did this because it solves a big problem that our customers face today. Most of the parts in the High Performance Analog segment are sole-sourced. That means that there is one source, and if customers have a problem obtaining a product from the primary source, they are out of luck. We provide an alternative source, and an assurance of supply they cannot have using only Maxim. In parallel with that, we are working on proprietary parts, which is the long-term future of the company. We want customers to think of us as a very different company. We want to develop things that are really different, unique, and cool to solve problems that are not being solved today. That is our basic product choosing methodology.

Our philosophy follows the words of Hall of Fame baseball player Willie Keeler: “Hit ‘em where they ain’t.” To us, this means don’t create the obvious products because customers will naturally gravitate toward the big companies. We are pursuing a niche strategy where we focus on markets that are big enough for us to make money but not so big that the larger companies would be interested in pursuing them.

What industry sectors are you looking at?We are pretty flexible in terms of what we do. The initial focus of the company is toward industrial types of companies. We have naturally evolved to low power applications. We are combining those two things together and it seems to be working.

As you target single-source applications components, is there any concern with IP as you design this part?We are designing in a different technology from the primary source, so almost by definition we have to use different architectures. We look at patents before we start. We do not want to infringe on someone else’s patents. We do not want to cause any unneeded issues.

We want to fill niches in the marketplace,

build our business up, and show engineers

that we can solve problems that have not

been solved before.

Can you tell us more about the manufacturing and testing?We are using TSMC as our primary foundry. They are a great partner and have been very supportive along the way. We do most of

our development in their 0.18µ technology but we are not limited to just that. We can use any technology that they have. That is the nice thing about our business model; we are flexible. We are able to pick the right technology for the product.

We are old school with regard to testing. We test everything that we develop. If we are guaranteeing our specifications over temperature, we test and make sure that it will perform exactly what we say it will.

How do you keep up with inventory?That is one of the big advantages for us. Because everything we are developing is on 8-inch wafers and we hold a lot of stuff in die banks, it does not cost us a huge amount of money to manufacture. If someone comes in with a huge order, we are able to manufacture, test, and ship it pretty fast.

Can you tell us about your low power op amp?Customers seem to love the TS1001 600nA, 0.8V Op Amp. Even customers who cannot use it seem to love it, which is really nice for us. It has been a great door opener for the company. Where we are seeing a lot of use for this part is in low-power applications. If someone needs bandwidth less than a kilohertz, and you want to reduce power consumption, it is perfect. Customers are getting really excited about it in those specific types of applications.

What can we expect to see from Touchstone in the future?We have a couple of different


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product families coming out at the end of September and October 2011. I am a little bit hesitant to say anything until they come out because the scary thing in our business is until you see it and know it works, it’s not a sure thing.

The thing that we really want customers to think about Touchstone is that the company is doing cool and unique things. Hopefully, as time goes on we will achieve that reputation, and customers will look

to us for those types of cool and unique products. We want to fill niches in the marketplace, build our business up, and show engineers that we can solve problems that have not been solved before.

How many products would you like to see Touchstone having in five years?Our minimum goal is 200, and it looks like we will easily be able to achieve that. We will continue

expanding our support staff around those products. Right now we have 25 people in the company, and we are always looking for good designers. We have a very high bar regarding who we hire. We have an extremely talented and cohesive team, so it is an elite group that people will be joining. ■


[email protected]



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FEATURED PRODUCTS

Fastest 14-bit Sample-and-Hold AmplifierDatel, a business unit of Murata Power Solutions has announced what it claims is the world’s fastest stand alone 14bit sample and hold amplifier.According to the company, the SHM-14 amplifier has a 70MHz full power bandwidth and 250MHz small signal bandwidth that achieves 12 and 14bit acquisitions within 25ns (/-0.012%) and 35ns (/-0.003%) respectively.Datel adds that the low power device has an aperture jitter within 1ps and a low output noise of 65uV rms. Output linearity is within +/-0.0023%, while digital sample/hold inputs are differential and compatible with all logic families including TTL, CMOS and ECL. For more information, please click here.

3-GHz, 10-Output Level TranslatorThe LMK00301 is a 3-GHz, 10-output differential fanout buffer intended for high-frequency, low-jitter clock/data distribution and level translation. The input clock can be selected from two differential inputs or one crystal input. The selected input clock is distributed to two banks of 5 differential outputs and one LVCMOS output. Each output bank can be configured as LVPECL, LVDS, or HCSL drivers, or disabled to reduce power. The LVCMOS output has a synchronous enable input for runt-pulse-free operation when enabled or disabled. The LMK00301 can be powered from a single 3.3 V supply, or dual 3.3 V/2.5 V supplies for lower power operation. The LMK00301 provides high performance, versatility, and power efficiency, making it ideal for replacing fixed-output buffer devices while increasing timing margin in the system. For more information, please click here.

Tightest Offset Current-Sense AmplifiersTouchstone Semiconductor, a developer of high-performance analog integrated circuit solutions, announced the TS1100 family of 1µA current-sense amplifiers that cut offset to 30µV, over 3X tighter than the closest competitor. The tight offset allows users to not have to increase power consumption in order to achieve improved accuracy. This is something that cannot be done with any other low power current sense amplifier. The TS1100 is available in four gain options from 25V/V to 200V/V, so customers can choose the ideal gain option for their unique application.For more information, please click here.

http://www.newelectronics.co.uk/electronics-news/worlds-fastest-stand-alone-14bit-sample-and-hold-amplifier/38859/

http://focus.ti.com/general/docs/nationalsemiconductorproducts.tsp?genericPartNumber=LMK00301

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Avago Technologies AEDR-850x three channel reflective encoders integrate an LED light source, photo detector and interpolator circuitry.

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Built in Interpolator of 1x, 2x, and 4x

1x, 2x and 4x via external pinouts

Base CPR resolution can be interpolated by end user

High operating frequencies: 55 kHz at 1x interpolation

Operating frequencies can be increased by external interpolator pinouts by maximum of 4x

Corresponding high RPM performance with increased frequencies

Index gating Options available for both gated and ungated versions

Catering for various user gating requirements

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Covering consumer, commercial and industrial applications

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TERAFLOPSoftware and HardwarePlatforms Enable Over

Michael ParkerSr Technical Manager

Processing Rates1Computing applications have long used floating point numerical processing, including many in CPU architectures, which are mathematically superior and support wide dynamic ranges. However, most embedded applications have traditionally used fixed point processing. Despite significantly increasing development complexity (often three times the time of floating point development), fixed point microprocessors, DSPs, and FPGAs can generally provide lower power consumption, lower costs, and in the case of FPGAs, much higher processing rates.

A new FPGA-based floating point flow is available that allows for the same high processing rate as enjoyed by fixed point applications to be achieved in floating point applications. A floating point co-processor which can be tightly coupled to FPGA hardware is also newly available, allowing both hardware and software floating point data processing to be leveraged. In addition, both of these new capabilities still support high throughput, fixed point processing for the parts of the DSP datapath that do not need the dynamic range of floating point processing. The result is a processing platform that

provides the advantages of both floating point and fixed point processing, while providing the flexibility to seamlessly partition and optimize the implementation between hardware and software.

Parallelism is a key advantage of a hardware solution like FPGAs, but it is often not applied to floating point signal processing because long latencies make the data dependencies in algorithms, such as matrix decomposition, difficult to manage. Therefore, the resultant systems offered poor performance levels and were uncompetitive with other platforms such as GPU or multi-core CPU architectures.

Altera has developed a floating point design flow that overcomes these issues. Rather than building a datapath from individual operators, the entire datapath is considered as a single function, with inter-operator redundancy factored out. Mantissa representation can be converted to hardware-friendly twos complement, and mantissa widths extended to reduce the frequency of normalizations. Elementary functions can be implemented as much as possible using hard multipliers,


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which offer guaranteed internal routing and timing, as well as low power and latency. New techniques can be applied for matrix decompositions, with the algorithms restructured to remove most of the data dependencies, so that parallel—and therefore high latency—datapaths can be used for these computations.

This approach is known as “Fused Datapath,” and when combined with a new 28nm Variable Precision DSP block architecture, offers extremely high data processing capabilities, in excess of one TeraFLOPS on a single FPGA die. The Fused Datapath technology has been embedded in Altera’s DSPBuilder design suite, which allows the full simulation and system design capabilities of Mathworks’ Matlab and Simulink to be utilized. This FPGA innovation in high-performance floating point enables the parallel hardware architecture advantages to be used in the very highest performance applications where the dynamic range of floating point is required.

An example of the matrix inversion processing capability with the latest floating point Cholesky matrix processing design is shown in Figure 1.

the FPGA, rather than just the reverse. The FPGA can implement the repetitive, high GFLOPS portions of the algorithm, while the co-processor can deal with the more complicated and data-dependent algorithms. This approach would combine the performance advantages of hardware implementations with the ease of development of software implementations.

The new Anemone floating point processor from BittWare connects to the FPGA via high-rate, low latency link ports. All access to off-chip memory is through the FPGA, as are off-board interfaces, such as PCIe backplanes or Ethernet ports. The Anemone processor is a multi-core design, currently offering 16 cores per chip, all interconnected in a mesh network with a shared memory model. Each core has 32 Kbytes of local memory, supports IEEE-754 floating point processing, and is individually programmable using ANSI-C. The 16-core Anemone chip offers 32 GFLOPS, while consuming only two watts of total power. Four Anemone chips, providing 128 GFLOPS, are available on an FMC (VITA 57) standard daughter card for use on FPGA host boards such as AMC, PCIe, and VPX. These are available today with Altera high end Stratix IV FPGAs, as shown in Figure 2, and will be offered later this year with Stratix V FPGAs.

The Anemone-to-FPGA interface is made transparent to the application using BittWare’s ATLANTiS FrameWork, which can bolt up seamlessly to Altera’s QSys FPGA system interconnect tool. This facilitates optimal partitioning of processing tasks between the Anemone and FPGA. With up to one TeraFLOPS of hardware floating point processing on Stratix V FPGAs, and 128 GLOPS of software floating point processing on Anemone, extremely high computational rate applications can be implemented in a low form factor, low power consumption platform.

An example application might be high-performance airborne radar systems. The FPGA can implement the digital downconversion, beamforming, MTI filtering, Doppler FFT processing, pulse compression, and matrix inversions needed in space-time adaptive processing (STAP). The Anemone processor is ideal for lower GFLOPs but more complex tasks. Examples of this are CFAR detection processing, computing beam forming coefficients, adapting and controlling radar modes, and transmit waveform generation. Low latency between the processing sub-systems is essential, and

For more information on Altera’s FPGA floating point design flow using Altera’s DSPBuilder Advanced Blockset and Mathworks’ Simulink, please refer to the recent BDTI whitepaper and toolflow evaluation available here.

Most floating point applications are currently implemented in software. With this new FPGA design flow now offering extremely high processing rates, a new architecture can be conceived that uses a tightly coupled C-programmable engine as a co-processor to

Figure 1: FPGA-based Floating Point Processing Throughput Example

Multi-Channel Cholesky Inversion Core

Multiple single precision Cholesky cores may be implemented with a single FPGA

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http://www.altera.com/floatingpoint


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these requirements are not easily met with GPU or CPU architectures. The combination of Anemone and Stratix FPGAs offer an ideal balance of TeraFlops processing power, flexibility to partition across hardware and software implementation, high GLOPS/Watt, and a very compact form factor.

This combination can also be ideal for any embedded application requiring high-performance computing power in military, medical imaging, wireless, or test equipment applications. Through the choice of FPGA and number of Anemone chips, the design can easily scale the level of processing power. The availability of Anemone-Stratix systems on BittWare’s COTS boards and systems supports rapid product development cycles.

Figure 2: Anemone-Stratix High Performance Floating Point Processing System featuring an AAFM co-processing mezzanine on an S4-3U-VPX.

About the Author

Michael Parker received his MSEE from Santa Clara University in California, and his BSEE from Rensselaer Polytechnic Institute in New York. He has over 20 years of DSP wireless engineering design experience with companies such as Alvarion, Soma Networks, TCSI, Stanford Telecom, and numerous startup companies. Michael joined Altera in January 2007, and is responsible for Altera’s entire digital signal processing (DSP) product planning.

Michael authored a book entitled Digital Signal Processing 101, published in 2010 and has written and published over 20 technical articles on DSP, floating point, and various other technology subjects. ■

ANENOMEFloating PointCo-Processor


GigE

4xControl

PortDataPort

Serd

es

(sRI

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xp, 1

0Gig

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10/100 Ethernet (Build Option)

FPGAStratix IV GX

(4SGX230/530)

Supported by:ATLANTiS Framework



FINeBridge

LEDs

P0

P1

P2

FLASHRS-232

JTAGHeader

32 4x

4x

3x

DDR3 SDRAM(up to 1 GB)

DDR3 SDRAM(up to 1 GB) 32

32DDR3 SDRAM

(up to 1 GB)

DDR3 SDRAM(up to 1 GB)32

32 LVDS pairs

Clocks, I2C, JTAG, Reset

Link Ports

4 bits DIO or RS 232/RS422(Build Options)

4 bits DIO(Build Option without 10/100 Eth.)


Bob StowePower Supply Design Consultant

System Perspectiveon Specifying ElectronicPower Supplies:

LoadCharacterizationIn a previous issue (Issue 19) we introduced the topic of “A System Perspective on Specifying Electronic Power Supplies.” In this article we will learn about the effect of the load on specifying a power supply.

The following drawing shows a power supply in a very simplified form, connected to a simplified load. The feedback and control circuit measures the output voltage, compares it to a reference (not shown), and adjusts the source voltage to maintain the load voltage constant. This process is not perfect, and the power supply specifications describe the deviation from perfection. The deviation from perfection must be within the requirements demanded by the load for the load to operate satisfactorily.

The Importance of Understanding the Load

The load imposes a major portion of the performance requirements on the power supply. The power supply is never a perfect black box and it is extremely important to treat it as a vital and integral part of your system. It

must meet the demands placed upon it by the load in several key performance measures. The most common measures are discussed below:

Static Requirements

Typically, the load requires one of the following parameters to be provided and controlled to within a certain tolerance band: voltage, current, or power. The other two parameters which are not controlled would be called compliance parameters. For example, a subassembly might be designed to operate with a controlled input voltage of 5 volts. When excited with a controlled input voltage of 5 volts, the subassembly responds by drawing up to 10 amperes, and consuming up to 50 watts of power. This means that the power supply must maintain the output voltage at 5 volts and be able to provide up to 10 amperes of current, since up to 10 amperes is what the load draws when excited by 5 volts. In this case, power is an alternate way of expressing compliance because power is the same as voltage times current.


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Some loads may require different controlled parameters at different times. Such an example is a battery charger which might require constant current for battery charge mode and constant voltage for battery maintenance mode.

Loads will require the controlled parameter to be within a certain tolerance band for proper operation. The power supply must maintain the controlled parameter within the tolerance band.

These parameters may be expressed in terms of average, RMS, or a peak value with a duration qualifier.

Dynamic Requirements

Loads also exhibit dynamic characteristics which change over time.

Time Transients

Many types of loads frequently change their effective impedance. Such an example might be a computer printer which exhibits rapid step changes in effective impedance. For such a device to function properly, the power supply must be able to rapidly source spurts of output current while maintaining the output voltage within a specified band. This means that the power supply must have enough output capacitance and high enough control loop bandwidth to maintain the output

voltage within the prescribed limits. Loads which have this type of behavior must have power supplies specified to limit the droop on the leading edge of the pulse, and recover to within a certain band of the steady state output in a prescribed time interval.

Voltage Dependence

Non-linear loads change impedance as voltage is increased. One example is a typical solid-state circuit which might draw very little current at low voltages, and then begin to draw current with a very rapid and nonlinear increase as voltage is increased.

A more problematic configuration is cascading a power supply with a second power supply of a switching converter design. A switching converter has a nonlinear negative resistance characteristic. At very low input voltages, below the turn-on threshold, the current may be miniscule. When the input voltage is increased to the turn-on threshold, the input current suddenly draws very high current. As the input voltage is increased, the input current decreases, following a constant power characteristic. If care is not taken in the first power supply design and cable length, the load (the switching converter) will cycle on and off because of the voltage drop in the cable length and/or the output impedance of the power supply.

Figure 1: Simplified representation of power supply and load.

Power Supply

Feedbackand

ControlVsource

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Iload Vload

_

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Frequency Dependence

Loads can create a frequency dependence which is not obvious to the untrained user. This frequency dependence is of at least two forms:

1. Resonant behavior can occur due to inductance and capacitance in both the power supply and the load. It is possible for power supplies to resonate with load capacitance or inductance if the power supply is not designed well for the load. This resonance will usually take place at frequencies determined by the reactive elements in the system. This effect is usually undesirable unless the system is designed to be resonant.

2. The power supply control loop behavior can be adversely influenced due to load capacitance and inductance. The presence of substantial capacitance or inductance can move the control loop poles and zeros, substantially changing the transient response and ripple rejection capability of the power supply by decreasing or possibll increasing the bandwidth of the power supply.

Temperature Dependence

Loads must operate in their intended environment. More often than not, the power supplies for these loads must operate in the same environment. These environments may be benign, such as a test laboratory, or severe, as in down-hole oil and natural gas exploration. The power supply must be able to work in the environment of the load, or the power supply environment must be separated from the load to allow satisfactory operation.

About the Author

Bob Stowe has over 21 years of experience in various disciplines related to electronic energy conversion, possesses a master’s degree in power electronics, and is a member of IEEE in good standing. He also has obtained his certification in power electronics from the University of Colorado (COPEC). Additionally, he graduated from the United States Naval Academy in 1984 with a bachelor’s degree in electrical engineering, and served for five subsequent years as a United States Naval Officer. As a former military officer, he is familiar with military project requirements. Bob now works for True Power Research as a Power Supply Design consultant. ■

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High Efficiency 5V, 10A Buck RegulatorISL95210The ISL95210 is a high-efficiency step-down regulator that can deliver 10A of output current from a 5V input. The small 4mmx6mm QFN package and only four external components provide a very small total solution size. Low resistance internal MOSFETs deliver excellent efficiency and permit full power operation in a +90°C ambient without airflow.

The regulator operates from an input voltage of 2.97V to 5.5V, and provides a 0.6% accurate output voltage over the full operating temperature range. Intersil's patented R4™ control architecture provides exceptional transient response with no external compensation components. The output voltage may be programmed by an internal DAC or by an external resistor divider (see “Output Voltage Programming” on page 11 for more details).

Several digital control signals provide flexibility for users that want additional features. Switching frequency, switching mode, output voltage margining and daisy-chained power-good functions are all programmed by these pins. The ISL95210 also includes comprehensive internal protection for overvoltage, undervoltage, overcurrent and over-temperature conditions.

Related Literature• See AN1485, “ISL95210 10A Integrated FET Regulator

Evaluation Board Setup Procedure”

Features• 10A Continuous Output Current

• 2.97V to 5.5V Input Voltage Range

• Up to 95% Efficiency

• Full Power Operation in +90°C Ambient without Airflow

• R4™ Control Architecture Delivers Excellent Transient Response Without Compensation

• Pin Selectable Output Voltage Programming

• ±0.6% Output Voltage Accuracy Over Full Operating Temperature Range

• Programmable Enhanced Light-Load Efficiency Operation

• Output Voltage Margining and Power-good Monitor

• Small 6mmx4mm QFN Package

Applications• Point-of-Load Power Supplies

• Notebook Computer Power

• General Purpose Power Rail Generation

FIGURE 1. 10A DC/DC CONVERTER USING ONLY 4 EXTERNAL COMPONENTS

FIGURE 2. EFFICIENCY OF CIRCUIT SHOWN IN FIGURE 1 (INCLUDES INDUCTOR LOSSES)

VINPVCC

ENPG_IN

VSEL1FSET

MPCTMSELVSEL0FCCM T-PAD

VOUTVCC

AGND

PGND

PGOOD

PHASEVOUT = 1.2V

VIN = 5V

LOUT

420nH

COUT220µF

1µF

10µFCIN

CONTROLSIGNALS

POWER GOOD

VCC

+

ISL95210

LOUTCOUT

= MPC0740LR42C (NEC/TOKIN)= 2TPLF220M5 (SANYO)

FSW= 800kHz

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EFFI

CIE

NC

Y (%

)

VIN = 5VVOUT = 1.2VFSW = 800kHz

November 17, 2011FN6938.3

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2011All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

Get the Datasheet and Order Samples

http://www.intersil.com

http://bit.ly/nHxRhB


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Date post:	27-Mar-2016
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EEWeb Pulse - Volume 24

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