L6258EP

16/22

5

APPLICATION INFORMATION

A typical application circuit is shown in Fig. 11.

Note: For avoid current spikes on falling edge of DISABLE a "DC feedback" would be added to the ERROR

Amplifier. (R1-R2 on Fig. 11).

5.1 Interference

Due to the fact that the circuit operates with switch mode current regulation, to reduce the effect of the wiring

inductance a good capacitor (100nF) can be placed on the board near the package, between the power supply

line (pin 13,31) and the power ground (pin 1,36,18,19) to absorb the small amount of inductive energy.

It should be noted that this capacitor is usually required in addition to an electrolytic capacitor, that has poor

performance at the high frequencies, always located near the package, between power supply voltage (pin

13,31) and power ground (pin 1,36,18,19), just to have a current recirculation path during the fast current decay

or during the phase change.

The range value of this capacitor is between few

µF and 100µF, and it must be chosen depending on application

parameters like the motor inductance and load current amplitude.

A decoupling capacitor of 100nF is suggested also between the logic supply and ground.

The EA_IN1 and EA_IN2 pins carry out high impedance lines and care must be taken to avoid coupled noise on this

signals. The suggestion is to put the components connected to this pins close to the L6258EP, to surround them with

ground tracks and to keep as far as possible fast switching outputs of the device. Remember also an 1 Mohm resistor

between EA_INx and EA_OUTx to avoid output current spike during supply startup/shutdown.

A non inductive resistor is the best way to implement the sensing. Whether this is not possible, some metal film

resistor of the same value can be paralleled.

The two inputs for the sensing of the winding motor current (SENSE_A & SENSE_B) should be connected di-

rectly on the sensing resistor Rs terminals, and the path lead between the Rs and the two sensing inputs should

be as short as possible.

Figure 11. Typical Application Circuit.

STEPPER

MOTOR

M

12mH 10

Ω

0.33

0.33

21

20

14

35

34

5

OUT2B

SENSE2

OUT2A

SENSE1

OUT1B

OUT1A

PH1

2

I0_1

4

I1_1

3

I2_1

32

I3_1

33

PH2

17

I0_2

15

I1_2

16

I2_2

23

I3_2

22

DISABLE

6

10nF

100nF

1nF

TRI_CAP

7

VS

13,31

VBOOT

12

VCP2

11

VCP1

10

9

GND

1,36

18,19

PWR_GND

VS

27

SIG_GND

28

D97IN626EP

VREF1

26

VREF2

29

EA_IN1

30

EA_OUT1

820pF

1M

25

EA_IN2

24

EA_OUT2

820pF

1M

VREF

8

L6258EP

PWSSO36

PACKAGE

R2 1M

R1 1M