Circuit description

L6229Q

12/28

Doc ID 15209 Rev 3

5.2

Logic inputs

Pins FWD/REV, BRAKE, EN, H1, H2 and H3 are TTL/CMOS and microcontroller compatible

logic inputs. The internal structure is shown in Figure 6. Typical value for turn-on and turn-off

thresholds are respectively V

Pin EN (Enable) has identical input structure with the exception that the drain of the

Overcurrent and thermal protection MOSFET is also connected to this pin. Due to this

connection some care needs to be taken in driving this pin. The EN input may be driven in

C

from 2.2 k

Ω to 180 kΩ. Recommended values for R

5.6 nF. More information on selecting the values is found in the overcurrent protection

section.

Figure 6.

Logic inputs internal structure

Figure 7.

Pin EN open collector driving

Figure 8.

Pin EN push-pull driving

5V

D01IN1329

ESD

PROTECTION

5V

5V

OPEN

COLLECTOR

OUTPUT

EN

DIAG

D02IN1378

ESD

PROTECTION

5V

PUSH-PULL

OUTPUT

EN

D02IN1379

DIAG

ESD

PROTECTION