TMC603_1 Datasheet, PDF(27/41 Page) TRINAMIC Motion Control GmbH & Co. KG. – Three phase motor driver with BLDC back EMF commutation hallFX™ and current sensing

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TMC603_1 Datasheet, PDF (27/41 Pages) TRINAMIC Motion Control GmbH & Co. KG. – Three phase motor driver with BLDC back EMF commutation hallFX™ and current sensing

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TMC603 DATA SHEET (V. 1.06 / 26. Mar. 2009)

Example:

fOSC = 175 kHz, IOUT = 0.2 A, VVM = 48 V:

For continuous operation, a 330ÂµH or 470ÂµH coil would be required. The minimum inductivity

would be around 100ÂµH.

Note:

Use an inductor, which has a sufficient nominal current rating. Keep switching regulator wiring

away from sensitive signals. When using an open core inductor, please pay special care to not

disturbing sensitive signals.

5.5.2 Charge pump

The Villard voltage doubler circuit relies on the switching regulator generating a square wave at the

switching transistor output with a height corresponding to the supply voltage. In order to work properly

the load drawn at +12V needs to be higher than the load drawn at the charge pump voltage. This

normally is satisfied when the IC is supplied by the step down regulator. For low voltage operation, the

charge pump voltage needs to be as high as possible to guarantee a high gate drive voltage, thus, a

dual Schottky diode should be used for the charge pump in low voltage applications.

5.5.3 Supply voltage filtering

As with most integrated circuits, ripple on the supply voltage should be minimized in order to

guarantee a stable operation and to avoid feedback oscillations via the supply voltages. Therefore,

use a ceramic capacitor of 100nF per supply voltage pin (VM to GND, VLS to GND and VCC to GND

and VCP to VM). Please pay attention to also keep voltage ripple on VCC pin low, especially when the

5V output is used to supply additional external circuitry. It also is important to make sure, that the

resistance of the power supply is low when compared to the load circuit. Especially high frequency

voltage ripple >1MHz should be suppressed using filter capacitors near the power bridge or near the

board power supply. The VM terminal is used, to detect short to GND situations, thus, it has to

correspond to the bridge power supply. In high noise applications, it may make sense to filter VCP

supply separately against ripple to GND. A large low ESR electrolytic capacitor across the bridge

supply (VM to GND) should also be used, because it effectively suppresses high frequency ripple. This

cannot be accomplished with ceramic capacitors.

5.5.4 Reverse polarity protection

Some applications need to be protected against a reversed biased power supply, i.e. for automotive

applications. A highly efficient reverse polarity protection based on an N channel MOSFET can simply

be added due to the availability of a charge pump voltage. This type of reverse polarity protection

allows feeding back energy into the supply, and thus is preferable to a pure diode reverse polarity

protection.

+Terminal

BC846

-Terminal

Reverse polarity power

10k

MOS (i.e. same type as

bridge transistors)

10k

+VM protected

(to bridge)

VCP

figure 19: adding a reverse polarity protection

5.5.5 Standby with zero power consumption

In battery powered applications, a standby function often is desired. It allows switching the unit on or

off without the need for a mechanical high power switch. In principle, the bridge driver MOSFETs can

switch off the motor completely, but the TMC603 and its switching regulator still need to be switched

off in order to reduce current consumption to zero. Only a low energy standby power supply will

remain on, in order to wake up the system controller. This standby power supply can be generated by

a low current zener diode plus a resistor to the battery voltage, buffered by a capacitor. The example

in the schematic uses a P channel MOSFET to switch off power for the TMC603 and any additional

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