L6208Q datasheet(13/34 Pages) STMICROELECTRONICS

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DocID018710 Rev 3

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L6208Q

Circuit description

5.2

Logic inputs

Pins CONTROL, HALF/FULL, CLOCK, RESET and CW/CCW are TTL/CMOS and µC

compatible logic inputs. The internal structure is shown in Figure 9. Typical values for turn-

on and turn-off thresholds are respectively Vth(ON) = 1.8 V and Vth(OFF) = 1.3 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 must be taken in driving this pin. The EN input may be driven in one

of two configurations, as shown in Figure 10 or 11. If driven by an open drain (collector)

structure, a pull-up resistor REN and a capacitor CEN are connected, as shown in Figure 10.

If the driver is a standard push-pull structure, the resistor REN and the capacitor CEN are

connected, as shown in Figure 11. The resistor REN should be chosen in the range from 2.2

 to 180 k. Recommended values for REN and CEN are respectively 100 k and 5.6 nF.

More information on selecting the values is found in Section 5.9.

Figure 9. Logic inputs internal structure

Figure 10. EN pins open collector driving

Figure 11. EN pins push-pull driving

L6208Q Fiches technique(PDF) 13 Page - STMicroelectronics