STMicroelectronics FlexSPIN: SPI configurable stepper and DC multi motor driver evaluation board EVAL6460 EVAL6460 Fiche De Données

Codes de produits

EVAL6460

Power bridges

L6460

68/139

Doc ID 17713 Rev 1

An internal DAC is used to digitally control the output regulated current. The available values
are chosen to provide a quasi sinusoidal profile of the current. The current limit in each
phase is decided by PhADAC[3:0] bits for phase A and PhBDAC[3:0] bits for phase B. The
table below describes the relation between the value programmed in the stepper DAC and
the current level.

Note:

The min and max values are guaranteed by testing the percentage of VSTEPREF that
allows the commutation of the Rsense comparator.

MAX

STEPREF

/ R

SENSE

To obtain the best phase approximation of a sinusoidal wave, the user needs to repeat the
final (100%) value. So the full values sequence should be as follows: 0, 1, 2, 3 … D, E, F, F,
F, E, D … 3, 2, 1, 0.

Even if the total spread shows overlapping between current steps, the monotonicity is
guaranteed by design.

When the internal sequencer the minimum angle resolution is nominally 5.625°, so
depending on the control mode chosen, the selectable steps are

Table 25

Table 24.

DAC

PhXDAC [3:0]

Phase current ratio respect to I

MAX

Min

Typ

Max

Unit

0000

(Hi-Z)

0001

9.8

% of I

MAX

0010

19.5

% of I

MAX

0011

29.0

% of I

MAX

0100

38.3

% of I

MAX

0101

47.1

% of I

MAX

0110

55.6

% of I

MAX

0111

63.4

% of I

MAX

1000

70.7

% of I

MAX

1001

77.3

% of I

MAX

1010

83.1

% of I

MAX

1011

88.2

% of IMAX

1100

92.4

% of I

MAX

1101

95.7

% of I

MAX

1110

98.1

% of I

MAX

1111

MAX