MC33385 Motorola, MC33385 Datasheet - Page 7

• Manufacturer Part Number: MC33385
• Description: Automotive Quad Low Side Driver
• Manufacturer: Motorola

www.DataSheet4U.com
4
input stages. Each output power transistor is protected against
short to V
output stage : overcurrent, short to GND, open-load and
overtemperature.
read out via a serial interface (SPI).
Output Stage Control
an individual control line (NON-Input). The logic level of the
control line is CMOS compatible. The output transistors are
switched off when the inputs are not connected.
Power Transistors
This causes a voltage limitation at the power transistors when
inductive loads are switched off. Drain voltage ramp occurring
when output is switched on or off, is within defined limits.
Output transistors can be connected in parallel to increase
current capability. In this case, the associated inputs should
be connected together.
for a time longer than t
above T
off. It remains switched off until the control signal on the NON-
Input is switched off and on again.
above the short current limit) or an overtemperature.
If the current through the output stage is lower than the IOL-
reference, after a filter time an OL failure will be recognized.
This measurement is active while the powerstage is switched
on.
MC33385
Short -Circuit to V
Short -Circuit to GND............................. = SCG
Open Load................................................. = OL (Lowest priority)
Introduction
Short-Circuit and Overtemperature Protection
Diagnostics
U
The device is a Quad Low Side Driver driven by four CMOS
A diagnostic logic recognizes four failure types at the
The failures are individually stored in a byte which can be
Each of the four output stages is switched ON and OFF by
Each of the four output stages has its own zenerclamp.
If the output current increases above the short current limit
Following failures at the output stage are recognized :
The SCB failure is recognized by an overcurrent (current
.com
OFF
BAT
then the power transistor is immediately switched
and by a zener clamp against overvoltage.
BAt
or overtemp...... = SCB (Highest priority)
SCB
or if the temperature increases
www.DataSheet4U.com
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
DEVICE DESCRIPTION
MOTOROLA
MC33385
The SCG failure will recognize when the drain voltage is lower
than the OL reference limit, while the output stage is switched
off. All four outputs have an independent overtemperature
detection and shutdown. All failures are stored in individual
registers.
interface. There is no failure detected if the powerstage
control time is shorter than the filter time.
failure register runs via the SPI link. If there is a failure stored
in the failure register, the first bit of the shift register is set to a
high level. With the H/L change on the NCS pin the first bit of
the diagnostic shift register will be transmitted to the SDO
output. The SDO output is the serial output from the
diagnostic shift register and it is tristated when the NCS pin is
high. The CLK pin clocks the diagnostic shift register. New
SDO data will appear on every rising edge of this pin and new
SDI data will be latched on every CLK’s falling edge into the
shift register. With the first positive pulse of the CLK, the
failure register will be cleared. There is no bus collision at a
small spike at the NCS. The CLK is always LOW while the
NCS-signal is changing.
Reset
Under voltage reset : as long as the V
V
register are reseted.
Reset pin : as long as the NRES-pin is low, following circuits
are reseted :
Undervoltage Protection
there is a voltage ramp at the OUT pin.
Diagnostic Interface
CCRES
They can be read by the microprocessor via the serial
The communication between the microprocessor and the
There are two different reset functions realised :
At low Vcc voltage, the device remains switched off even if
, the powerstages are switched off and the failure-
• Powerstages
• Failure register
cc
voltage is lower than
www.DataSheet
www.DataSheet
www.DataSheet
www.DataSheet4U
7
4U
4U
4U.com
.com
.com
.com