E-L8150 STMICROELECTRONICS [STMicroelectronics], E-L8150 Datasheet - Page 17

• Manufacturer Part Number: E-L8150
• Description: Brushless motor predriver
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L8150
Figure 5.
Smooth Drive basic functionality is to apply to the motor the voltage waveforms represented
in the following pictures
Figure 6.
This kind of profile, which realizes waveforms that are differentially sinusoids, is digitally
described by a table of 36 8-bit samples stored in a decoding circuit. The final amplitude of
the voltage applied on the outputs is obtained by multiplying each sample by a value
generated through an 8-bit ADC, whose input is coming from the speed control.
The motor is controlled in voltage mode, so no current control compensation network is
required. Actuation is done on motor windings through a fixed frequency PWM conversion.
Since Smooth Drive is basically a voltage mode driving there can be the need of shifting the
applied profile with respect to the BEMF (here sensed through the Hall sensors). This
applied phase shift is called Torque Optimizer.
The value (expressed in electrical degrees, hereafter referred to as degrees) can be chosen
applying an analog voltage to TO pin, that will be internally converted using a 4-bit A/D.
The phase shift range is from 2.5 to 40 degrees with a 2.5-degrees step. As a reference the
correspondence between phase shift values and analog voltages is reported in
16 bit counter operation
Smooth drive pattern (forward)
(Figure
6) in case of forward rotation (CW).
Operating description
Table
21.
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