L6226Q datasheet(10/28 Pages) STMICROELECTRONICS

10 / 28 page

Circuit description

L6226Q

10/28

4.2

Logic inputs

Pins IN1A, IN2A, IN1B, IN2B, ENA and ENB are TTL/CMOS and microcontroller compatible

logic inputs. The internal structure is shown in Figure 4. Typical value for turn-on and turn-off

thresholds are respectively Vthon = 1.8 V and Vthoff = 1.3 V.

Pins ENA and ENB are commonly used to implement overcurrent and thermal protection by

connecting them respectively to the outputs OCDA and OCDB, which are open-drain

outputs. If that type of connection is chosen, some care needs to be taken in driving these

pins. Two configurations are shown in Figure 5 and Figure 6. If driven by an open drain

(collector) structure, a pull-up resistor REN and a capacitor CEN are connected as shown in

Figure 5. If the driver is a standard push-pull structure the resistor REN and the capacitor

CEN are connected as shown in Figure 6. The resistor REN should be chosen in the range

from 2.2 k

Ω to 180 kΩ. Recommended values for R

EN and CEN are respectively 100 kΩ and

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

section.

Figure 4.

Logic inputs internal structure

Figure 5.

ENA and ENB pins open collector driving

Figure 6.

ENA and ENB pins push-pull driving

D01IN1329

ESD

PROTECTION

L6226Q Datasheet(PDF) 10 Page - STMicroelectronics