L6235PD datasheet(12/35 Pages) STMICROELECTRONICS

12 / 35 page

Circuit description

L6235

12/35

DocID7618 Rev 2

5.2

Logic inputs

Pins FWD/REV, BRAKE, EN, H1, H2 and H3 are TTL/CMOS compatible logic inputs. The

internal structure is shown in Figure 6. Typical value for turn-ON and turn-OFF thresholds

are respectively Vth(ON) = 1.8 V and Vth(OFF) = 1.3 V.

Pin EN (enable) may be used to implement overcurrent and thermal protection by

connecting it to the open collector DIAG output. If the protection and an external disable

function are both desired, the appropriate connection must be implemented. When the

external signal is from an open collector output, the circuit in Figure 7 can be used. For

external circuits that are push-pull outputs the circuit in Figure 8 could be used. The resistor

REN should be chosen in the range from 2.2 K to 180 K. Recommended values for REN

and CEN are respectively 100 K and 5.6 nF. More information for selecting the values can

be found in Section 10: Non-dissipative overcurrent detection and protection on page 22.

Figure 6. Logic input internal structure

Figure 7. Pin EN open collector driving

Figure 8. Pin EN push-pull driving

L6235PD Fiches technique(PDF) 12 Page - STMicroelectronics