l99dz80ep STMicroelectronics, l99dz80ep Datasheet - Page 34

• Manufacturer Part Number: l99dz80ep
• Description: Door Actuator Driver
• Manufacturer: STMicroelectronics

Application information
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(E < 1 mJ) can be dissipated by the internal ESD-diodes in freewheeling condition. For
inductive loads (L > 100 µH) an external freewheeling diode connected between GND and
the corresponding output is required. The low side driver at ECV does not have a freewheel
diode built into the device.
Open-load detection
The open load detection monitors the load current in each activated output stage. If the load
current is below the open load detection threshold for at least t
load bit is set in the status register. Due to mechanical/electrical inertia of typical loads a
short activation of the outputs (e.g. 3 ms) can be used to test the open load status without
changing the mechanical/electrical state of the loads.
Overcurrent detection
In case of an overcurrent condition, a flag is set in the status register. If the overcurrent
signal is valid for at least T
switched off to reduce the power dissipation and to protect the integrated circuit. If the
overcurrent recovery bit of the output is cleared, the microcontroller has to clear the status
bits to reactivate the corresponding driver.
Current monitor
The current monitor output sources a current image at the current monitor output, which has
three fixed ratios of the instantaneous current of the selected high-side driver. Outputs with
a resistance of 500 mΩ and higher have a ratio of 1/2000, except for OUT8, which has a
ratio of 1/6500, and those with a lower resistance one of 1/10000. The signal at output CM is
blanked after switching on the driver until correct settlement of the circuitry. The bits
CM_SEL<3:0> define which of the outputs are multiplexed to the current monitor output CM.
The current monitor output allows a more precise analysis of the actual state of the load
rather than the detection of an open- or overload condition. For example, it can be used to
detect the motor state (starting, free running, stalled). Moreover, it is possible to control the
power of the defroster more precisely by measuring the load current. The current monitor
output is enabled after the current-monitor blanking time, when the selected output is
switched on. If this output is off, the current monitor output is in high-impedance mode.
PWM mode of the power outputs
Each driver has a corresponding PWM enable bit, which can be programmed by the SPI
interface. If the PWM enable bit is set, the output is controlled by the logically AND-
combination of an internally generated PWM signal and the output control bit of the
corresponding driver. The PWM-Frequency of all outputs can be programmed to either
122 Hz of 244 Hz typically. The on-duty-cycle is set by the four 7-bit registers, which control
one PWM counter each. Therefore the maximum on-time is 100% - 1 LSB.
1 LSB = 100/128 %. Which output uses which corresponding PWM driver can be seen in
the SPI register definition. When programming a specific duty-cycle, the output on/off times
as well as the slopes must be taken into account.
FOC
Doc ID 18260 Rev 4
, the overcurrent flag is set and the corresponding driver is
FOL
the corresponding open-
L99DZ80EP