DRV8308_15 Datasheet, PDF (38/60 Pages) Texas Instruments – DRV8308 Brushless DC Motor Controller

DRV8308
SLVSCF7A – FEBRUARY 2014 – REVISED OCTOBER 2014
www.ti.com
Register Map (continued)
Table 7. Register Descriptions
ADDRESS
0x00
0x01
0x02
0x03
BIT
15:12
11
10
9
8
7:6
5:4
3:2
1
0
15:8
7:0
15:8
7:0
15
14:12
11:0
NAME
DESCRIPTION
Autogain Setpoint
AG_SETPT
0000 = 3 Hz
0001 = 6 Hz
0010 = 12 Hz
0011 = 24 Hz
0100 = 48 Hz
0101 = 95 Hz
0110 = 191 Hz
0111 = 382 Hz
1000 = 763 Hz
1001 = 1.5 kHz
1010 = 3 kHz
1011 = 6 kHz
1100 = 12 kHz
1101 = 24 kHz
1110 = 49 kHz
1111 = 98 kHz
ENPOL
ENABLE terminal polarity
0 = Device is active when ENABLE is high
1 = Device is active when ENABLE is low
DIRPOL
DIR terminal polarity
0 = Normal DIR pin behavior
1 = Inversed DIR pin behavior
BRKPOL
BRAKE terminal polarity
0 = Brake when BRAKE is high
1 = Brake when BRAKE is low
Synchronous rectification
SYNRECT _{0 = Disabled}
1 = Enabled
The PWM frequency used on the external FETs
PWMF
00 = 25 kHz
01 = 50 kHz
10 = 100 kHz
11 = 200 kHz
Speed control mode
SPDMODE
00 = Clock Frequency Mode
01 = Clock PWM Mode
10 = Internal Register PWM Mode
11 = Reserved
FG select
FGSEL
00 = Use HALL_U to generate FG
01 = Use XOR of all three Hall sensors
10 = Use FG amplifier input
11 = Use TACH input signal
BRKMOD
Motor brake mode
0 = Coast when ENABLE is inactive (outputs 3-state)
1 = Brake when ENABLE is inactive (all low-side FETs on)
RETRY
Retry mode
0 = Latch off in case of fault
1 = Automatic retry in case of fault
RSVD Reserved
ADVANCE Commutation timing advance versus Hall signals; each count is 1 / 960 the Hall_U period
SPDREVS
After the MINSPD and SPEEDTH criteria are met, SPDREVS adds a minimum number of
Hall_U periods that must occur for LOCK to be set
MINSPD Sets the minimum Hall_U period that LOCK can be set; each count is 2.56 ms
BASIC
Basic operation
0 = Normal device operation
1 = Disables ADVANCE functionality and forces 3-Hall 120° commutation
Speed change tolerance for LOCK
SPEEDTH ^{000 = 1/512 rev (0.20%) 011 = 1/64 rev (1.56%) 110 = 1/8 rev (12.5%)}
001 = 1/256 rev (0.39%) 100 = 1/32 rev (3.13%) 111 = 1/4 rev (25%)
010 = 1/128 rev (0.78%) 101 = 1/16 rev (6.25%)
MOD120 Scales the input duty cycle in PWM modes
TYPE ⁽¹⁾
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
–
RW
RW
RW
RW
RW
RW
(1) R = Read Only; RW = Read or Write. Fault registers can only be written 0.
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