LP3907 Datasheet, PDF (28/42 Pages) National Semiconductor (TI) – Dual High-Current Step-Down DC/DC and Dual Linear Regulator with I2C Compatible Interface

LP3907 Control Registers
Register
Address
0x02
0x07
0x10
0x11
0x20
0x23
0x24
0x25
0x29
0x2A
0x2B
0x38
0x39
0x3A
Register
Name
ICRA
SCR1
BKLDOEN
BKLDOSR
VCCR
B1TV1
B1TV2
B1RC
B2TV1
B2TV2
B2RC
BFCR
LDO1VCR
LDO2VCR
Read/
Write
R
R/W
R/W
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Register Description
Interrupt Status Register A
System Control 1 Register
Buck and LDO Output Voltage Enable Register
Buck and LDO Output Voltage Status Register
Voltage Change Control Register 1
Buck1 Target Voltage 1 Register
Buck1 Target Voltage 2 Register
Buck1 Ramp Control
Buck2 Target Voltage 1 Register
Buck2 Target Voltage 2 Register
Buck2 Ramp Control
Buck Function Register
LDO1 Voltage control Registers
LDO2 Voltage control Registers
INTERRUPT STATUS REGISTER (ISRA) 0X02
This register informs the System Engineer of the temperature status of the chip.
Name
Access
Data
D7-2
—
—
Reserved
Reset
0
D1
Temp 125°C
R
Status bit for thermal warning
PMIC T>125°C
0 – PMIC Temp. < 125°C
1 – PMIC Temp. > 125°C
0
D0
—
—
Reserved
0
CONTROL 1 REGISTER (SCR1) 0X07
This register allows the user to select the preset delay sequence for power-on timing, to switch between PFM and PWM mode for
the bucks, and also to select between an internal and external clock for the bucks.
D7
Name —
Access —
Data Reserved
Reset 0
D6-4
D3
EN_DLY
—
R/W
—
Selects the preset Reserved
delay sequence
from EN_T assertion
(shown below)
010
1
D2
D1
D0
FPWM2
FPWM1
ECEN
R/W
R/W
R/W
Buck2 PWM /PFM Buck 1 PWM /PFM Reserved
Mode select
Mode select
0 – Auto Switch PFM - 0 – Auto Switch PFM -
PWM operation
PWM operation
1 – PWM Mode Only 1 – PWM Mode Only
0
0
0
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