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Device configuration

UM1771

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DocID026392 Rev 2

Device configuration

This section offers an overview of the basic configuration steps which are required to make

the demonstration board operative.

Warning:

Important - the device configuration is mandatory. The

default configuration is not operative.

Before changing the device configuration verify that the

device is in high impedance status (power stage is disabled).

4.1

Advanced current control

The following configuration gives good results with most of motors:

The impacts of the timing parameters are explained in the application note AN4158- “Peak

current control with automatic decay adjustment and predictive current control: basics and

setup”.

4.2

Overcurrent protection

The overcurrent protection detection is implemented by measuring the current flowing into

each integrated MOSFET.

The overcurrent protection threshold should be set just above the current rating of the

motor:

IOCDth > Imax,r.m.s. × √2

For example: if the maximum phase current of the motor is 2 Ar.m.s., the overcurrent

protection should be set to about 3 A.

Warning:

Important - it is strongly discouraged to disable the

overcurrent shutdown. It may result in critical failures.

Table 4. Phase current control

Parameter

Value

Unit

Minimum ON time

s

Minimum OFF time

s

Maximum fast decay (TOFF_FAST)

s

Maximum fast decay at step change (FAST_STEP)

s

Target switching time

s

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