SMOOTH DRIVING concept.

It is based on the idea of driving the motor wind-

ing through 3 sinusoidal voltages dephased of

120 degrees. The motor is controlled in voltage

mode, so no current control compensation net-

work is required.

Each profile is digitally described by 36 bytes

stored in a ROM memory.

These sinusoidal signals are modulated by multi-

plying each sample by a value stored in the KVAL

register. Using this kind of profiles it is possible to

obtain great advantages such as torque ripple

and acoustic noise reduction and lower EMI. An

easier track following is ensured, since vibration

are reduced.

The clock signal on the chip can be synchronized

to the external application clock signal.

An internal circuit can limit the current. The

threshold is fixed with a internal 0.2 V reference.

The device generates:

- a current generator to define output voltage

slew rate

- a 3.3 V reference to bias hall sensor.

- the HFG open drain output signal for speed

regulation.

The device includes :

- a circuit for thermal shutdown with hysteresis.

- a low voltage detector

In the STANDBY state the main functions of the

device are turned off, in order to minimize the

power consumption.

The STANDBY state of the device is imposed by:

- Thermal shutdown

- stand by signal from

µP

PIN CONNECTIONS

DESCRIPTION (continued)

PRS

N.C.

N.C.

VM

U

N.C.

V

W

RF

H BIAS

ISR

DGND

AGND

SRC

HFG

FSYS

STB

1

3

2

4

5

6

7

8

9

22

21

20

19

18

16

17

15

23

10

24

N.C.

PHS

D01IN1174

RF1

PWMIN

11

14

13

12

H+

H-

STB

PRS

VM

U

V

RF

W

RF1

H+

PHS

HBIAS

ISR

AGND

VCC

DGND

SRC

HFG

FSYS

1

3

2

4

5

6

7

8

9

18

17

16

15

14

12

13

11

19

10

20

H-

PWMIN

D98IN928A

SO20

SSO24

L7203

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