L6374 Просмотр технического описания (PDF) - STMicroelectronics

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производитель

L6374

Industrial quad line driver

STMicroelectronics 

Overtemperature protection (OVT)

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Overtemperature protection (OVT)

L6374

If the chip temperature exceeds Th (measured in a central position in the chip) the chip

deactivates itself.

The following actions are taken:

● all the output stages are forced in the "three state" condition, i.e. are disconnected from

the output pins; only the clamping diodes at the outputs remain active;

● the signal Diag is activated (active low).

Normal operation is resumed as soon as (typically after some seconds) the chip

temperature monitored goes back below Th -HT.

The different upper and lower thresholds with hysteretic behavior, assure that no intermittent

conditions can be generated.

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Undervoltage protection (UV)

The supply voltage is expected to range from 11 V to 35 V, even if its reference value is

considered to be 24 V.

In this range the L6374 operates correctly. Below 10.8 V the overall system has to be

considered not reliable.

Consequently the supply voltage is monitored continuously and a signal, called UV, is

internally generated and used.

The signal is "on" as long as the supply voltage does not reach the upper internal threshold

of the Vs comparator (called Vsh). The UV signal disappears above Vsh.

Once the UV signal has been removed, the supply voltage must decrease below the lower

threshold (i.e. below Vsh -Hys1) before it is turned on again.

The hysteresis Hys1 is provided to prevent intermittent operation of the device at low supply

voltages that may have a superimposed ripple around the average value.

The UV signal inhibits the outputs, putting them in three-state, but has no effect on the

creation of the reference voltages for the internal comparators, nor on the continuous

operation of the charge-pump circuits.

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