ST7FMC1K2B3 STMICROELECTRONICS [STMicroelectronics], ST7FMC1K2B3 Datasheet - Page 217

• Manufacturer Part Number: ST7FMC1K2B3
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

MOTOR CONTROLLER (Cont’d)
REFERENCE REGISTER (MREF)
Read/Write
Reset Value: 0000 0000 (00h)
Bit 7 = HST: Hysteresis Comparator Value.
This read only bit contains the hysteresis compa-
rator output.
0: Demagnetisation/BEMF comparator is under
1: Demagnetisation/BEMF comparator is above
Bit 6 = CL: Current Loop Comparator Value.
This read only bit contains the current loop compa-
rator output value.
0: Current detect voltage is under V
1: Current detect voltage is above V
Bit 5= CFAV: Current Feedback Amplifier entry
0: OAZ(MCCFI1) is the current comparator entry
1: MCCFI0 is the current comparator entry
HST
V
V
Validation
7
REF
REF
CL
6
CFAV HFE1
5
4
HFE0 HFRQ2 HFRQ1 HFRQ0
3
2
CREF
CREF
1
0
Bits 4:3 = HFE[1:0]: Chopping mode selection
These bits select the chopping mode as shown in
the following table.
Table 71. Chopping mode
Bits 2:0 = HFRQ[2:0] : Chopper frequency selec-
These bits select the chopping frequency.
Table 72. Chopping frequency selection
Note: The chopper signal has a 50% duty cycle.
HFRQ2 HFRQ1 HFRQ0
HFE1
tion
0
0
1
1
0
0
0
0
1
1
1
1
HFE0
0
1
0
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Both High and Low channels
On High channels only
On Low channels only
ST7MC1xx/ST7MC2xx
F
F
Chopping mode
mtc
frequency
Chopping
mtc
1.33 MHz
100 KHz
200 KHz
400 KHz
500 KHz
800 KHz
1 MHz
2 MHz
= 16MHz
= 8MHz
OFF
F
666.66 MHz
frequency
Chopping
mtc
100 KHz
200 KHz
250 KHz
400 KHz
500 KHz
50 KHz
1 MHz
= 4MHz
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