L6474 datasheet(22/51 Pages) STMICROELECTRONICS

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Functional description

L6474

22/51

Doc ID 022529 Rev 2

Figure 7.

OSCIN and OSCOUT pin configurations

Note:

When OSCIN is UNUSED, it should be left floating.

When OSCOUT is UNUSED it should be left floating.

6.9

Overcurrent detection

When the current in any of the power MOSFETs exceeds a programmed overcurrent

threshold, the STATUS register OCD flag is forced low until the overcurrent event has

expired and a GetStatus command is sent to the IC (see paragraphs 9.1.13 and 9.1.9).

Overcurrent event expires when all the power MOSFET currents fall below the programmed

overcurrent threshold.

The overcurrent threshold can be programmed through the OCD_TH register in one of 16

available values ranging from 375 mA to 6 A with steps of 375 mA (see Table 9, paragraph

9.1.9).

It is possible to set whether or not an overcurrent event causes the MOSFET turn-off

(bridges in high impedance status) acting on the OC_SD bit in the CONFIG register (see

paragraph 9.1.12). The OCD flag in the STATUS register is raised anyway (see Table 28,

paragraph 9.1.13).

When the IC outputs are turned off by an OCD event, they cannot be turned on until the

OCD flag is released by a GetStatus command.

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