Best FET and FET Driver Choices for an H-Bridge?

[joprinz]

Hello Everyone,

I'm designing a 50V 6A+ Bipolar Stepper Motor driver. I'm new to Discrete H-Bridges and plus I'm not very familiar with all the MOSFETS and MOSFET Drivers in the market. I was wondering if you can share your experience with New MOSFETS and MOSFET Drivers.

So far the Drivers I came across are

    * Intersil HIP4082
    * IRS2304
    * Microchip TC4424


And The MOSFETS

    * STF40NF06
    * IRFZ24
    * IRFZ44
    * IRF9530 and IRF540


Well I came across plenty of other parts as well. Lets jus say the more U seek the More U find in this case. Just before I decide on one part I come across another which seemed better(btw My knowledge on MOSFETS is Very Limited. So cant really say if its Really a Better one I jus found). So I was wondering if someone can help me pick the right Driver and MOSFET for a Driver with the following Specs

    * Dual H-Bridge (MOSFET) Bipolar Stepper Driver 6A+ @ 50V
    * Step Sequencing will be done using a PIC or Atmega uC
    * Step Rate will be in the range of 2000-3500 Pulses/Second
    * Current Limiting is done using an External PWM @ 20kHz


Please Advice!

Thank You.

Joe!

[free]

Maybe you can visit www.allegromicro.com
A lot of good products for stepper motor driver

[Naste]

joprins

I have try use atmega8 as uC and irf 840 as mosfet to make stepper controller..but i haven't try with IR (mosfet driver) as h-bridge driver
my advise, you can use atmega as uC and use  l298 that pararelled its output, it can supply up to 8A....

[mmladenovic]

MC33883 from Motorola is very good IC for H bridge.
Milan.

[Walkura]

Personaly i tend to use the irf gatedrivers .
The IR2101 i used on several occasions (and aplications) in combination with mcu's .
http://www.irf.com/product-info/datasheets/data/ir2101.pdf
About the mosfets .
For powers like this a to220 will do easily ,but do pay a bit attention to your selection .
Irf 540 has a quite high Rdson (0,077 Ohm) http://www.datasheetcatalog.org/datasheet/stmicroelectronics/9387.pdf
 where a IRF1407 has 0,0078 Ohm http://www.irf.com/product-info/datasheets/data/irf1407.pdf.
This means that the I2R losses are higher .
6 Ampere2 x 0,077 Ohm = 2,772 Watt of heat (excluding swithing losses)
6 Ampere2 x 0,0078 Ohm = 0,28 Watt of heat (excluding swithing losses)
The last fet you could even use it uncolled or just a small to220 radiator
(with practical use i had powers like this uncooled @35 Celcius ,even though i did use radiators that was more the be prepared for reversed polarity)
Seen the low speed of switching i wouldn't bother to much about gate requirements .
In the datasheets you can see the amounts of nano Coulombs needed to charge / discharge your gate .
Coulombs is the amount of charge , calculated as Amperes x Seconds.
Logicly follows from this that the faster you want to dis-charge the gatecapacity with the needed amount of Coulombs the higher the amperage gets .
The bigger the die of the mosfet the bigger the capacitance of the gate ,and following of that so is the current to open and close it .


Goodluck .

[joprinz]

Thanks Free, Naste, Mmladenovic, Walkura for your inputs.

Walkura, Yes the IRF1407 would indeed make a Big Difference in terms of Heat dissipation.

Meanwhile I have a new parallel project up n running using the Allegro A3986 Stepper Driver. Has anyone successfully tested this chip? The A3986 seems to have the WHOLE package. It has Microstepping, PWM, FET driver, 2wire Step Dir Control and upto 50V operation. But somehow there seems to be such a serious lack for a tested driver schematic. Hope someone out here has a tested design???

Thank You,

Joe!

[localcrack]

You may use microchip TC4469

or

Micrel MIC4469