L9951 STMicroelectronics, L9951 Datasheet - Page 21

• Manufacturer Part Number: L9951
• Description: IC REAR DOOR ACT DVR POWERSO-36
• Manufacturer: STMicroelectronics
• Type: DC Motor Driverr

Specifications of L9951

• Applications: Automotive
• Current - Supply: 7mA
• Voltage - Supply: 7 V ~ 28 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: PowerSO-36 Exposed Bottom Pad
• Operating Current: 20mA
• Operating Temperature Classification: Automotive
• Motor Controller Type: DC Motor Driver
• Package Type: PowerSO
• Operating Supply Voltage (min): 7V
• Operating Supply Voltage (max): 28V
• Supply Current: 20 mA
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L9951 / L9951XP
3.10
3.11
3.12
PWM input
Each driver has a corresponding PWM enable bit which can be programmed by the SPI
interface. If the PWM enable bit is set, the outputs OUT1 to OUT5 are controlled by the
logically AND-combination of the signal applied to the PWM input and the output control bit
in input data register1.
Cross-current protection
The three half-brides of the device are cross-current protected by an internal delay time. If
one driver (LS or HS) is turned-off the activation of the other driver of the same half bridge
will be automatically delayed by the cross-current protection time. After the cross-current
protection time is expired the slew-rate limited switch-off phase of the driver will be changed
to a fast turn-off phase and the opposite driver is turned-on with slew-rate limitation. Due to
this behavior it is always guaranteed that the previously activated driver is totally turned-off
before the opposite driver will start to conduct.
Programmable softstart function to drive loads with higher
inrush current
Loads with start-up currents higher than the over-current limits (e.g. inrush current of lamps,
start current of motors and cold resistance of heaters) can be driven by using the
programmable softstart function (i.e. overcurrent recovery mode). Each driver has a
corresponding over-current recovery bit. If this bit is set, the device will automatically switch-
on the outputs again after a programmable recovery time. The duty cycle in over-current
condition can be programmed by the SPI interface to be about 12% or 25%. The PWM
modulated current will provide sufficient average current to power up the load (e.g. heat up
the bulb) until the load reaches operating condition.
The device itself cannot distinguish between a real overload and a non linear load like a light
bulb. A real overload condition can only be qualified by time. As an example the
microcontroller can switch on light bulbs by setting the over-current Recovery bit for the first
50ms. After clearing the recovery bit the output will be automatically disabled if the overload
condition still exits.
Figure 9.
Example of programmable softstart function for inductive loads
Doc ID 14173 Rev 8
Application information
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