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Small 3 phase motor controller 2.5A

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Member level 4
Sep 23, 2008
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Can anyone recommend a 3 phase driver IC that might be able to handle breaking and microstepping on a 4 pole 3 phase motor that draws MAX. 2.5A, or if you might have some recommendation for a ready made module that is 40 x 50 mm in size height is not a problem it can be stacked.

You are talking about a BLDC? What voltage?

If you look on ebay for BLDC motor controller, there are thousands of listings.

Actually I am using a Faulharber motor. The problem with the motorcontrollers as well as the thousand available online and elsewhere is the size. Its not as I mentioned (50 x 40) mm. I tried builting one around the DRV10963
problem was that it didnt have the brake function I required. Its good for fans and stuff and little else more.

Is the 2.5A RMS or locked rotor based on Vcoil/Rcoil which tends to be 1/8 the RMS current under load, so your driver must be 1 to 8% of Rcoil of motor.

In your specs, look for these keywords.

Supply voltage U = ?? V DC
Terminal resistance R = ?? Ohms

Then surge or stall or brake current is U/Rs

Doing a sudden reverse polarity would double the current with double the Voltage swing and must be consider inertia, duration and VI power dissipation in driver and motor and rate of direction changes.

The best brake is a grounded MOSFET driver output or Vout=0 Single polar (or N type to gnd instead of P type to V+ for unidirection motor or in other words a bipolar driver (BJT) or complementary half bridge CMOS or MOSFET driver between V+ and gnd. A full bridge with 2 sets of complementary drivers for bi-directional control.

In all cases you want < 10% drop on the driver at full current ( pref 1%) thus ESR driver must be <10% Terminal Resistance.

Again FETS are defined by RdsOn and BJT's in ultralow VceSat are often defined by Rce or effective ESR. ( See Diodes Inc for details or specs.) which is fundamentally Vce_Sat/Imax=Rce or the saturated junction resistance ( well below dynamic higher R where ESR is almost constant within 50%)

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