TPS22981

SLVSBM6 – DECEMBER 2012

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FAULTZ Output

The TPS22981 has an open-drain FAULTZ output. When the device is in a fault condition, the FAULTZ output

will pull low. Connect FAULTZ through a pull-up resistance to V3P3. A Fault occurs during any of the following

conditions.

•

EN = 1 and V3P3 is in UVLO (device enabled and V3P3 is in an under-voltage condition)

•

EN = 1 and in Thermal Shutdown condition

•

EN = 1, HV_EN = 1, and VHV is in UVLO (device enabled, high voltage enabled, and VHV is in an under-

voltage condition)

Table 3 shows these conditions and the resulting FAULTZ output. Note, when V3P3 is below the UVLO

FAULTZ output is unknown.

Table 3. FAULTZ Output Conditions (when in an under-voltage condition, UVLO = 1)

EN

HV_EN

Thermal Shutdown

V3P3 UVLO

VHV UVLO

FAULTZ (Active Low)

0

X

X

X

X

1

1

X

X

1

X

0

1

X

Yes

0

X

0

1

0

No

0

1

1

1

1

No

0

1

0

1

X

No

0

0

1

It is recommended that the pull-up resistance on FAULTZ be 100k

Ω and must be greater than or equal to 30kΩ.

INPUT INDUCTIVE BOUNCE AT SHORT CIRCUIT

When a significant inductance is seen at the VHV input, suddenly turning off large current through the device

may produce a large enough inductive voltage bounce on the VHV pin to exceed the maximum safe operating

condition and damage the TPS22981. To prevent this, reduce any inductance at the VHV input.

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