mc33982b Freescale Semiconductor, Inc, mc33982b Datasheet - Page 19

• Manufacturer Part Number: mc33982b
• Description: Single Intelligent High-current Self-protected Silicon High Side Switch 2.0m
• Manufacturer: Freescale Semiconductor, Inc

FAULT MODE
driving the
• Over-temperature fault
• Over-voltage and under-voltage fault
• Open load fault
• Over-current fault (high and low)
OVER-TEMPERATURE FAULT (NON-LATCHING)
shutdown circuitry in the output structure. Over-temperature
detection is enabled when the output is in the ON state.
results in the faulted output turning OFF until the temperature
falls below the T
until action is taken by the MCU to shut OFF the output, or
until the offending load is removed.
in the status register and cleared after either a valid SPI read
or a power reset of the device.
OVER-VOLTAGE FAULT (NON-LATCHING)
fault (OVF) condition on the VPWR pin. The output remains
in the OFF state until the over-voltage condition is removed.
When experiencing this fault, the OVF fault bit is set in bit
OD1 and cleared after either a valid SPI read or a power reset
of the device.
disabled through the SPI (bit OV_dis).
UNDER-VOLTAGE SHUTDOWN (LATCHING OR
NON-LATCHING)
6.0V. As long as the V
specified range, the internal logic states within the device will
be sustained.
undervoltage threshold, (VPWRUV) the output will turn off,
FS will go to Logic [0], and the fault register UVF bit will be set
to 1.
recovers:
Analog Integrated Circuit Device Data
Freescale Semiconductor
The 33982B indicates the following faults as they occur by
The 33982B incorporates over-temperature detection and
For the output, an over-temperature fault (OTF) condition
When experiencing this fault, the OTF fault bit will be set
The 33982B shuts down the output during an over-voltage
The over-voltage protection and diagnostic can be
The output(s) will latch off at some battery voltage below
In the cases where the battery voltage drops below the
Two cases need to be considered when the battery level
• If the output(s) command is (are) low, FS will go to
• If the output command is ON, then FS will remain at
Logic [1], but the UVF bit will remain set to 1 until the
next read operation.
Logic [0]. The output must be turned OFF and ON again
FS
pin to Logic [0]:
SD(HYS)
DD
. This cycle will continue indefinitely
level stays within the normal
PROTECTION AND DIAGNOSIS FEATURES
fault condition is removed, except for over-current and in
some cases under-voltage.
available (and reset) via the SO pin during the first valid SPI
communication (refer to
(bit UV_dis = 1). In this case, the FS and UVF bit do not report
any under-voltage fault condition and the output state will not
be changed as long as the battery voltage does not drop any
lower than 2.5 V.
OPEN LOAD FAULT (NON-LATCHING)
the output. Output open load fault (OLF) is detected and
reported as a fault condition when the output is disabled
(OFF). The open load fault is detected and latched into the
status register after the internal gate voltage is pulled low
enough to turn OFF the output. The OLF fault bit is set in the
status register. If the open load fault is removed, the status
register will be cleared after reading the register.
(bit OL_dis).
detection circuitry (OL_dis bit sets to logic [1]) in case
of a permanent open load fault condition.
OVER-CURRENT FAULT (LATCHING)
detection levels (I
high detection levels (I
The two selectable, simultaneously active over-current
detection levels, defined by I
Figure
(I
current low detection level and the over-current condition
exceeds the programmed over-current time period (t
device will latch the output OFF.
then the device will immediately latch the fault and turn OFF
the output, regardless of the selected t
until the device is commanded OFF and then ON again.
OCL0
The
Fault information is retained in the fault register and is
The under-voltage protection can be disabled through SPI
The 33982B incorporates open load detection circuitry on
The open load protection can be disabled through the SPI
The 33982B has eight programmable over-current low
If the load current level ever reaches the selected over-
If at any time the current reaches the selected I
For both cases, the device output will stay off indefinitely
to re-enable the state of output and release FS. The
UVF bit will remain set to 1 until the next read operation.
: I
6. The eight different over-current low detection levels
FS
OCL7
pin will automatically return to Logic [1] when the
) are likewise illustrated in
It is recommended to disable the open load
OCL
PROTECTION AND DIAGNOSIS FEATURES
) and two programmable over-current
OCH
Table
FUNCTIONAL DEVICE OPERATION
) for maximum device protection.
OCH
16).
and I
OCL
OCL
Figure
, are illustrated in
driver.
6.
OCH
OC
x
level,
), the
33982
19