THE MAGAZINE FOR COMPUTER APPLICATIONS - …

1 THE MAGAZINE FOR COMPUTER APPLICATIONSC ircuit Cellar Online offers articles illustrating creative solutionsand unique APPLICATIONS through complete projects, practicaltutorials, and useful design PAGESA Guide to online information about: H-Bridges & Class-Dby Bob PaddockThis month's topic, H-Bridges, was brought about because I needed tofind a small H-Bridge device. As I looked around the H-Bridge pages, Ikept running into APPLICATIONS covering Class-D power amplifiers, whichseemed like it would make a interesting topic. To many people, hearingClass-D brings about thoughts of audio amplifiers, but it does haveother interesting before we tackle that, let's cover the basics, brought to you by theletter HH-Bridges and Class- (1 of 13) [8/24/2001 8:05:06 AM]The course in Mechatronic Design by instructors: Prof. Gary Fedder(ECE and Robotics) and Prof.

2 Howie Choset (Mechanical Engineeringand Robotics) has a good introduction to H-Bridge Motor DriveElectronics as part of their lecture ECE 480 Home Page Where a Picture is Worth a Thousand &Twenty-four Words is worth a stop when you are looking for any kind ofcircuit, even an H-Bridge. They show a simple method to prevent yourH-Bridge from becoming a fuse tester. The fuse tester mode happenswhen both switches in the same leg of the H are turned onsimultaneously, causing a short of the power supply to Using MOSFETs page is dedicated to learning about MOSFETs inH-Bridges and Class- (2 of 13) [8/24/2001 8:05:06 AM]DC motor control and starts with a short MOSFET primer, thenprogresses into H-Bridges of different W.'s page is about building your own affordable CNC system usinglow-cost or free step and direction software, and closed loop servocontrol electronics.

3 His H-Bridge theory section sums up the H-Bridge:There are two kinds of amplifiers for driving motors, linearand PWM. One of the benefits of linear amps is theyproduce a lot less electrical noise that can interfere withother electronics. The drawback is that they are bulky,expensive, and generate a lot of heat. PWM amps are justthe opposite they are small, inexpensive and generate lotsof electrical noise. The reason PWM amps run cooler isbecause most of the time the transistors are in cut-off orsaturation where they generate the least amount of putting together this web page, one of the areas that kept comingin during my searching was fields related to robotics. One of the moreinteresting areas that covered H-Bridges is BEAM machines. Beam-Tekdescribes BEAM technology:"The ideas and technology underlying BEAMR obotics is one of of the technological challenges facingrobotics is the environment these machinesare immersed within is highly complicatedand ever-changing.

4 Forget the brain, let usfocus on a simple stimulus-response basedability within a machine. Smart bodies thatcan handle the real world on their own. Wecan work on the brain later, but the body andnervous system should be the beginningand the foundation for all work in livingmachines."B E A M - R o b o t i c s - T e kMark W. Tilden gives an example relevant to the subject at hand in hisBiomech Motor Bridges, with a circuit based on an SCR-like currentamplifier arrangement which, when biased correctly, works quite wellfor most push-pull inductive actuators from solenoids to stepper out the other BEAM areas on Motors and Motor Drivers and theBEAM Robotics Web and Class- (3 of 13) [8/24/2001 8:05:06 AM]A Web Ring links member web sites together to transform their sitesinto linked circles. Their purpose: to allow more visitors to reach themquickly and easily.

5 To your benefit, you can locate related sites thatdon't always show up in the search MicroSystems Inc. offers several Bridge Motor Drivers. Forexample: Dual PWM Full Bridge Microtechnology Corporation specializes in high-power andhigh-voltage Apex Circuit Design Center enables you to quickly and easilymatch your application to a specific Apex part. Motion control,deflection, piezo drivers, and others are all here in pdf format. You canview a part-specific schematic or download the entire collection foroffline new SA08 and SA18 hybrid PWM amplifiers from ApexMicrotechnology operate off a wide 16-V 500-V single supply thataffords their design in APPLICATIONS without transformers where the walloutlet voltages ranged from 115 230 VAC. Both the full H-bridge SA08and half-bridge SA18 provide 20 A of output current,Composite Modules Industries, specializes in high-reliability medicalelectronics.

6 The need for intelligent motor controllers and smart powermodules capable of surviving autoclave sterilization is a necessity forsurgical electronic devices and equipment. CMI guarantees itselectronics to exceed 3,000 autoclave cycles. H-BRIDGE POWERDRIVERFH1208S8 Features:Single supply voltage 20 to 80 V @ up to 12 Am H-Bridges and Class- (4 of 13) [8/24/2001 8:05:06 AM]Thermal protectionm Crossover current protectionm TTL-CMOS inputsm Electrically isolated packagem QUADPAC N-CHANNELPOWER H-BRIDGEQ2010 NFeatures:Isolated hermetic packagel Low Rds(on)l 20 A source currentl 100 V breakdown voltagel The Q2010N is a packaged set of four N-Channel MOSFETs. It is anideal replacement in APPLICATIONS requiring multiple discrete FETs. Thishermetically packaged product features the latest advanced MOSFETand packaging technology.

7 The four MOSFETs are electrically isolatedfrom the package. The small size allows for a high degree of flexibility incircuit design and eliminates the need for isolation spacers and theiradded thermal resistance when mounting to a heat Corporation has sold most of their Semiconductor line to Intersil,but no matter what you want to call them, they have some of the besttutorial papers on Class-D HIP4080 is a member of the HIP408X family of high-frequencyH-Bridge driver ICs. The HIP4080 H-Bridge driver IC provides the abilityto operate from 8 VDC to 80 VDC busses for driving Channel MOSFETH-Bridges. The HIP4080, packaged in either 20-lead DIP or 20-leadSOIC, provides peak gate current drive of A. A combination ofbootstrap and charge-pumping techniques is used to power the circuitrythat drives the upper MOSFETs of the H-Bridge. The bootstraptechnique supplies the high instantaneous current needed for turning onthe power devices while the charge pump provides enough current tomaintain bias voltage on the upper driver sections and 80 Peak, High Frequency Full Bridge FET DriverHIP4081 80 Peak, High Frequency Full Bridge FET DriverHIP4080A 80 Peak, High Frequency Full Bridge FET DriverHIP4081A 80 Peak, High Frequency Full Bridge FET DriverAN9758 Multimedia, Cool Audio, Cool Media Understanding MultimediaStandardsAN9759 Multimedia, Cool Audio, Cool Media Signal Processing Blocks- A TutorialIP4080 AEVAL2 Class-D Audio II Evaluation BoardHIP200 ACREF 200W Class D Subwoofer Amplifier (Cool Audio)HCA250 ACREF 250W Class D Subwoofer AmplifierH-Bridges and Class- (5 of 13) [8/24/2001 8:05.]

8 06 AM]HCA125 ACREF 125/220 Watt Full Bandwidth Class D AmplifierLinFinity has been acquired by Microsemi LX1720 is a highly integrated switching Class-D stereo poweramplifier controller IC with power and size features that make it ideal formultimedia COMPUTER APPLICATIONS , as well as other APPLICATIONS wherehigh-fidelity sound is required. With input voltage ranging from7-V 15-V, the LX1720 is designed to operate over the full 20 Hz to 20kHz audio range. Signal distortion measurements using industrystandard 1 kHz signal yields THD + noise levels < 1% (10 W output). Itshigh efficiency (>92%) eliminates the need for heat sinks whiledelivering more than 10 WRMS across 8 ohms per channel (20 WRMS stereo) with ohm SO-8 power LX1720: High-Efficiency Class-D, Stereo Audio AmplifierController A Simple Current-Sense Technique Eliminating a SenseResistor.

9 This App. Note can be used in many areas such as powersupplies, it is not limited to Micrel Semiconductor MIC4467/4468/4469 Quad MOSFET driver has APPLICATIONS in driving all four MOSFETsin an Semiconductor, formerly a division of Motorola, makes and deliversthe power and interface semiconductors that turn technology on andconnect it to your : New Components Simplify Brush DC Motor Drives. A varietyof new components simplify the design of brush motor drives. One is abrushless motor control IC which is easily adapted to brush include multiple power MOSFETs in H-Bridge configuration, anew MOS turn-off device, and gain-stable opto level shifters. Severalcircuits illustrate how the new devices can be used in practical motordrives, in particular to control speed in both directions and operate froma single power : Basic Servo Loop Motor Control Using the MC68HC05B6 MCU A Proportional Derivative (PD) closed-loop speed control for abrush motor can be created using four integrated circuits, two optodiscretes and less than 200 bytes of code.

10 The use of an MCU infeedback-control systems is increasingly commonplace. It is justifiedwhen system flexibility is needed. For example, to accommodatevarying drive motors or to allow wear parameters to be stored inEEPROM. This design is based on an MC68HC05B6 MCU and anH-Bridges and Class- (6 of 13) [8/24/2001 8:05:06 AM]MPM3004 power MOSFET : Design Considerations for a Low Voltage N-Channel H-BridgeMotor Drive Complementary MOSFET half-bridges are commonly usedin low-voltage motor drives to simplify gate drive design. However, theP-channel FET in the half-bridge usually has higher ON-resistance or islarger and more expensive than the N-channel device. The alternativeis to use an N-channel half-bridge, which uses silicon more efficientlyand minimizes cost and conduction losses. The tradeoff is usually amore complex gate drive; this note looks at ways of minimizing gatedrive complexity and also discusses diode snap, shoot-through current,and general design NEC PD16837GS is a quad H-bridge driver IC using powerMOSFETs in the output stage.