IPS2050H datasheet(12/32 Pages) STMICROELECTRONICS

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Protections and diagnostic

The IC integrates several protections to help the design of robust applications.

7.1

Under-voltage lock-out

The IC is turned off if the voltage on VCC pin falls below the turn-off threshold (VUVOFF). Normal operation restarts

after VCC exceeds the turn-on threshold (VUVON). Turn-on and turn-off thresholds are defined in Table 4.

7.2

Over-temperature

The device is protected against overheating in case of overload conditions. During the driving period (when the

MCU is forcing the INX pin high), if the output is overloaded, the device suffers two different thermal stresses, one

related to the junction temperature of each output channel, and the other related to the whole case temperature.

The two thermal faults (Thermal Junction and Thermal Case) have different trigger thresholds: TJSD and TCSD,

respectively.

Usually, in thermal stress conditions due to overload, the junction thermal shutdown is the first protection that

is activated: each output channel (OUTX) is turned off when its junction temperature (TJX) is higher than the

activation threshold (TJSD) and turned back on when it goes below the reset threshold (TJR). This behavior

continues while overload on the output persists. When the thermal protection is active for OUTX, the related FLTX

(current source) becomes active accordingly.

If the thermal protection is active and the temperature of the case (TC) increases over the case protection

threshold (TCSD), then the thermal case protection is activated and the output is switched off until the junction

temperature of each channel in fault and case temperature fall below the respective reset thresholds (TCR and

TJR). The FLTX pins are active even when thermal case events occur.

Figure 7 shows the thermal protection behavior, while Figure 8 and Figure 9 show typical temperature trends and

output vs. input state.

IPS2050H, IPS2050H-32, IPS2050HQ, IPS2050HQ-32

Protections and diagnostic

DS13779 - Rev 3

page 12/32

IPS2050H датащи(PDF) 12 Page - STMicroelectronics