LTC3576 Datasheet, PDF (29/48 Pages) Linear Technology – Switching Power Manager with USB On-the-Go + Triple Step-Down DC/DCs

LTC3576/LTC3576-1
OPERATION
Input Data
Table 3 illustrates the four data bytes that may be written
to the LTC3576/LTC3576-1.
The first byte at sub-address 0 controls the servo volt-
age for switching regulators 1 and 2. The second byte at
sub-address 1 controls the servo voltage of switching
regulator 3 and the enable signals for all three switching
regulators, as well as the enable signal for the PowerPath
switching regulator to power up V_BUS for USB on-the-go.
The servo voltages are decoded in Table 4. The default
servo voltage is 0.8V.
Table 3. I²C Serial Port Mapping*
A7 A6 A5 A4 A3 A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0
Switching Regulator 1 Voltage Switching Regulator 2 Voltage Switching Regulator 3 Voltage
(See Table 4)
(See Table 4)
(See Table 4)
Reset Value 1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0
Switching
Regulator 1
Modes
(See Table 5)
Switching
Regulator 2
Modes
(See Table 5)
Switching
Regulator 3
Modes
(See Table 5)
Input Current
Limit
(See Table 6)
Unused
Reset Value 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
*The A7-A0 and B7-B4 bits default to 1 and all other bits default to 0 when the chip is powered and DV_CC = 0.
Table 4. Switching Regulator Servo Voltage
A7 A6 A5 A4 Switching Regulator 1 Servo Voltage
A3 A2 A1 A0 Switching Regulator 2 Servo Voltage
B7 B6 B5 B4 Switching Regulator 3 Servo Voltage
0
0
0
0
0.425
0
0
0
1
0.450
0
0
1
0
0.475
0
0
1
1
0.500
0
1
0
0
0.525
0
1
0
1
0.550
0
1
1
0
0.575
0
1
1
1
0.600
1
0
0
0
0.625
1
0
0
1
0.650
1
0
1
0
0.675
1
0
1
1
0.700
1
1
0
0
0.725
1
1
0
1
0.750
1
1
1
0
0.775
1
1
1
1
0.800
3576f
29