L6460 Datasheet, PDF (75/139 Pages) STMicroelectronics – SPI configurable stepper and DC multi motor driver

L6460
Power bridges
voltage thresholds) using serial interface. The feedback reference voltage is selected by
writing the SelFBRef[1:0] bits in the Aux1SwCfg or Aux2SwCfg registers.
The switching regulators have four possible PWM duty cycles that can be changed using
SPI according to Table 28.
Table 28. PWM specification
AuxXPWMTable[1:0] Typical duty cycle value
00
10%
01
13%
10
24%
11
61%
Comments
Default state for AUX1
Default state for AUX2
14.1.7
Regulation loop
As seen before L6460 contains 2 regulation loops for switching regulators that are used
when bridge 3 is used as a regulator. These loops are assembled using internal
comparators and filters similar to that used in main switching regulator.
When bridge 3 is not used for this purpose or when only one regulation loop is needed, the
control loop is available on a GPIO output thus enabling the customer to assembly a basic
buck switching regulator using an external Power FET. The comparators used in the above
mentioned regulation loops are general purpose low voltage (3.3 V) comparators; when the
relative regulation loop is not used they can be accessed as shown in the Figure 20.
Figure 20. Internal comparator functional block diagram
GPIOx
GPIOx
DECODE
LOGIC
GPIOy
GPIOy
DECODE
LOGIC
GPIOyMode
+
V _3v3
GPIOzMod
e
GPIOz Value From SPI
GPIOz
DECODE
LOGIC
GPIOz Logic
Driver
GPIOz
Doc ID 17713 Rev 1
75/139