STMicroelectronics FlexSPIN: SPI configurable stepper and DC multi motor driver evaluation board EVAL6460 EVAL6460 Data Sheet

Product codes
EVAL6460
Page of 139
L6460 Switching 
regulator 
controller
Doc ID 17713 Rev 1
53/139
   
   
   
Figure 12.
Switching regulator controller functional blocks
13.1 
Pulse skipping operation
Pulse skipping strategy has already been explained on main switching regulator section.
This regulator has 4 possible PWM duty cycles that can be changed writing in the 
SelSwCtrPWM bits in the SwCtrCfg register using SPI.
         
 
V
out
 
La 
V
supply
 
 
Driver 
Control 
Logic 
Current Sense
 
Charge pump Voltage
 
Voltage  
Loop Control 
VFBRef 
Under voltage 
Threshold 
Filter 
R
a
 
R
b
 
From Central Logic 
Regulator Freq 
To Central Logic 
under voltage flag
 
R
sense
 
V
SWDRV_gate
 
N-CH Fet 
An
al
og Mu
Vref = 3 V 
Vref=0.8V 
SelFBRef[1:0] 
An
al
og Mu
Uv Threshold 1 
SelFBRef 
Uv Threshold 2 
Vref = 3V 
Vref=0.8V 
V
SWDRV FB
 
V
SWDRV SW
 
V
SWDRW_sns
 
Table 12.
Switching regulator controller PWM specification
SwCtrCfg register
Duty cycle value
Comments
SelSwCtrPWM[1:0]
Typical 
00
9%
01
12%
10
22.5%
Default state
11
58%