LTC3589_12 Datasheet, PDF (39/50 Pages) Linear Technology – 8-Output Regulator with Sequencing and I2C

LTC3589/LTC3589-1/
LTC3589-2
OPERATION
Table 17. LTC3589 Command Register Table
REG
NAME B[7]
B[6]
B[5]
0x12
SCR2 Mask PGOOD LDO4
LTC3589-2
Hard
Start-Up:
Shutdown:
LDO4
Start-Up:
B[4]
LDO4
Start-Up:
B[3]
LDO4
Start-Up:
B[2]
LDO4
Start-Up:
B[1]
LDO4
Start-Up:
B[0]
LDO4
Start-Up:
DEFAULT
0000 0000
0 = Allow 0 = Don’t Wait
PGOOD
for Output <
Timeout Hard 300mV Before
Shutdown. Enable
0 = Don’t Wait 0 = Don’t Wait 0 = Don’t Wait 0 = Don’t Wait 0 = Don’t Wait 0 = Don’t Wait
for Output < for Output < for Output < for Output < for Output < for Output
300mV Before 300mV Before 300mV Before 300mV Before 300mV Before < 300mV
Enable
Enable
Enable
Enable
Enable
Before Enable
1 = Allow 1 = Wait for 1 = Wait for 1 = Wait for 1 = Wait for 1 = Wait for 1 = Wait for 1 = Wait
PGOOD Hard Output < 300mV Output < Output < Output < Output < Output <
for Output
Shutdown. Before Enable 300mV Before 300mV Before 300mV Before 300mV Before 300mV Before < 300mV
Enable
Enable
Enable
Enable
Enable
Before Enable
0x20
VCCR LDO2
Start LDO2 Step-Down Start
Step-Down Start
Step-Down Start
0000 0000
Reference Slew:
Switching Step-Down Switching Step-Down Switching Step-Down
Select:
Regulator 3 Switching Regulator 2 Switching Regulator 1 Switching
Reference Regulator 3 Reference Regulator 2 Reference Regulator 1
Select:
Slew:
Select:
Slew:
Select:
Slew:
0=
0 = Went
L2DTV1[4-0]
1 = GO
1=
L2DTV2[4-0]
0=
0 = Went
B3DTV1[4-0]
1= GO
1=
B3DTV2[4-0]2
0=
0 = Went
B2DTV1[4-0]
1= GO
1=
B2DTV2[4-0]
0=
B1DTV1[4-0]
1=
B1DTV2[4-0]2
0 = Went
1= GO
0x21
CLIRQ
0x23
B1DTV1 Step-Down Switching
PGOOD
Step-Down Switching Regulator 1 Feedback Reference Input (V1)
Regulator Switch DV/DT
Mask:
Control:
0 = PGOOD 00000 = 362.5mV
00 = 1ns
Low When 11001 = 675mV
01 = 2ns
Slewing
11111 = 750mV
10 = 4ns
12.5mV Step Size
11 = 8ns
1 = PGOOD
Not Forced
Low When
Slewing.
0001 1001
0x24
B1DTV2 Keep-Alive Phase
Step-Down Step-Down Switching Regulator 1 Feedback Reference Input (V2)
Mode:
Select:
Switching 00000 = 362.5mV
0 = Normal 0 = Clock
Shutdown Phase 1
1 = Keep-Alive 1 = Clock
Regulator 1 11001 = 675mV
Clock Rate 11111 = 750mV
0 = 2.25MHz ^{12.5mV Step Size}
Phase 2
1 = 1.12MHz
0001 1001
0x25
VRRCR LDO2 Dynamic Reference Step-Down Switching
Step-Down Switching
Step-Down Switching
Slew Rate:
Regulator 3 Dynamic
Regulator 2 Dynamic
Regulator 1 Dynamic
Reference Slew Rate:
Reference Slew Rate:
Reference Slew Rate:
1111 1111
00 = 0.88mV/μs
01 = 1.75mV/μs
10 = 3.5mV/μs
11 = 7mV/μs
00 = 0.88mV/μs
01 = 1.75mV/μs
10 = 3.5mV/μs
11 = 7mV/μs
00 = 0.88mV/μs
01 = 1.75mV/μs
10 = 3.5mV/μs
11 = 7mV/μs
00 = 0.88mV/μs
01 = 1.75mV/μs
10 = 3.5mV/μs
11 = 7mV/μs
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