L6225 datasheet(6/10 Pages) STMICROELECTRONICS

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L6225

Figure 1. Switching rates definition

CIRCUIT DESCRIPTION

The L6225 is a dual full bridge IC designed to drive DC or stepper motors and other inductive loads. Each bridge has

4 power DMOS transistors with a typical RDS(ON) of 0.3 Ohm. Any of the 4 half bridges can be controlled indepen-

dently by means of the 4 TTL/CMOS compati ble inputs IN1A,IN2A, IN1B, IN2B, and 2 enable ENA, ENB .

External connectio ns are provided so that sensing resistor can be added for constant current chopping applicatio n.

A non dissipative current sensing on the supply rails of the high side power DMOSs of each bridge, an internal

reference and an internal open drain, with a pull down capability of 4mA (typical value), will pull to GND the EN-

ABLE pin of the bridge under fault conditions, turning OFF all the four PowerDMOSs. This ensures a protection

against short circuit to GND and between two phases of each of the two independent full bridges. By using an

external R-C on the EN pins, the off time before recovering normal operation conditions after a fault can be

easily programmed, by means of the accurate threshold of the logic inputs. Note that protection against short

to the supply rail is typically provided by the external current control circuitry. The trip point of this protection is

set at 2.8A (typ value).

50 %

90 %

10 %

En or IN

IOUT

tD(OFF) tOFF

tD(ON) t(ON)

L6225 Fiches technique(PDF) 6 Page - STMicroelectronics