MC33888FB Freescale Semiconductor, MC33888FB Datasheet - Page 21

• Manufacturer Part Number: MC33888FB
• Description: IC SWITCH QUAD H-SIDE W/CS 64QFP
• Manufacturer: Freescale Semiconductor
• Type: High Side/Low Side Driverr

Specifications of MC33888FB

• Input Type: SPI
• Number Of Outputs: 12 ( 4 High Side, 8 Low Side)
• On-state Resistance: 40 mOhm
• Current - Output / Channel: 10A
• Current - Peak Output: 60A
• Voltage - Supply: 6 V ~ 27 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

of the outputs. FS provides real time monitoring of the
overvoltage fault. For the high-side outputs, FS provides real
time monitoring of the open load and overtemperature. For
the low-side outputs, the FS is latched to a logic [0] for open
load, overtemperature, and overcurrent faults. The latch is
cleared by toggling the state of the faulted output or by
bringing RST low.
OVERTEMPERATURE FAULT
shutdown circuitry into each individual output structure.
Overtemperature detection occurs when an output is in the
ON state. When an output is shut down due to an
overtemperature condition, no other output is affected. The
output experiencing the fault is shut down to protect itself
from damage. A fault bit is loaded into the status register if the
overtemperature condition is removed, and the fault bit is
cleared upon the rising edge of CS.
during an overtemperature condition. If the temperature falls
below the recovery level, T
turned back ON only after the output has first been
commanded OFF either through the SPI or the ILS,
depending on the logic configuration.
will result in the output(s) turning OFF until the temperature
falls below the T
until action is taken by the MCU to shut the output(s) OFF.
OVERCURRENT FAULT REQUIREMENTS: LOW-
SIDE OUTPUT
greater than I
LS11, and 800 mA minimum value for LS4, LS6, LS8, LS10).
The status of the corresponding bit in the CLOCCR register
determines whether a specific output shuts down or
continues to operate in an analog current limited mode until
either the overcurrent condition is removed or the thermal
shutdown limit is reached
overcurrent shutdown mode is disabled, the fault reporting is
disabled as well.
Analog Integrated Circuit Device Data
Freescale Semiconductor
The FS pin is driven to a logic [0] when a fault exists on any
The 33888 incorporates overtemperature detection and
For the low-side outputs, the faulted output is latched OFF
For the high-side output(s), an overtemperature condition
An overcurrent condition is defined as any current value
LIM
LIM(HYS)
(500 mA minimum value for LS5, LS7, LS9,
. This cycle will continue indefinitely
(Figure
LIM(HYS)
LOW = Logic 0
V
THRES
10, page 27). If the
, then the output can be
Figure 7. Low-Side Output OFF Open Load Detection
V
+
–
2.0 V–4.0 V
OFD(THRES)LS
33888
MOSFET
OVERVOLTAGE FAULT
condition on the V
state until the overvoltage condition is removed. Fault status
for all outputs is latched into the status register. Following an
overvoltage condition, the next write cycle sent by the SO pin
of the 33888 is logic [1] on OD11: OD0, indicating all outputs
have shut down. If the overvoltage condition is removed, the
status register can be cleared by a rising edge on
OPEN LOAD FAULT
every output. A high-side or low-side output open load fault is
detected and reported as a fault condition when the
corresponding output is disabled (OFF) if it was configured
for open load detection by setting the appropriate bit to
logic [0] (HS3 : HS0) or logic [1] (LS11: LS4) in the OLFCR
register (see
the status register after the internal gate voltage is pulled low
enough to turn off the output. If the open load fault is removed
or if the faulted output is commanded ON, the status register
can be cleared by a rising edge on CS. Note that the device
default state will enable the high-side open load detection
and disable the low-side open load detection circuits,
respectively.
circuitry (OL bit sets to logic [1]) in case of a permanent open
load fault condition.
to a logic [1] in the OLCR register, the overcurrent protection
shutdown circuitry will be enabled for that output. When a
low-side output is commanded ON either from the SPI or the
ILS pin, the drain of the low-side driver will be monitored for
a voltage greater than the fault detection threshold (3.0 V
typical). If the drain voltage exceeds this threshold, a timer
will start and the output will be turned off and a fault latched
in the status register after the timeout expires. The faulted
output can be retried only by commanding the output OFF
and back ON either through the SPI or the ILS pin, depending
on the logic configuration. If the fault is gone, the retried
output will return to normal operation and the status register
can be cleared on a rising edge of CS. If the fault remains, the
The 33888 shuts down all outputs during an overvoltage
The 33888 incorporates open load detection circuitry on
The high-side open load fault is detected and latched into
It is recommended to disable the open load detection
For the low-side output of interest, if a D11: D4 bit was set
50 mA
Figure
PWR
7).
pin. The outputs remain in the OFF
V
R
PWR
L
FUNCTIONAL DEVICE OPERATION
OUT
OPERATIONAL MODES
CS
.
33888
21