LT3582 LINER [Linear Technology], LT3582 Datasheet - Page 13

• Manufacturer Part Number: LT3582
• Description: I2C Programmable Boost and Single Inductor Inverting DC/DC Converters with OTP
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
CMDR: The Command Register is used to control various
functions of the chip. During shutdown and power-up the
CMDR is initialized to 00h.
The RSEL (Register Select) bits are functional only for
the LT3582. The LT3582-5 and LT3582-12 function as if
the RSEL bits are always “0”. These bits perform three
functions:
• Each RSEL bit instructs the chip whether to use the
• Each RSEL bit determines if I
• OTP programming only programs data to the bytes with
Setting the SWOFF bit immediately disables the Boost and
Inverting power switches and opens the output disconnect
PMOS switch. It is recommended to set this bit before
writing new confi guration data. This can prevent unex-
pected chip behavior while modifying the confi guration
and also forces a soft-start after SWOFF is cleared (see
Soft-Start and Power-up Sequencing). Writing “1” to the
RST bit resets the internal I
Reading bit 6 of the CMDR returns the FAULT bit indicating
if an OTP programming attempt may have failed. FAULT
is cleared during reset, power-up, or by writing a “1” to
the CF (Clear Fault) bit. Conditions that set the FAULT bit
are (1) OTP programming in which the V
low or (2) attempted OTP programming when the LOCK
bit is set. OTP write attempts that set the FAULT bit due
to low V
device should be discarded. Attempts to re-program the
OTP memory after the FAULT bit has been set are not
recommended. Finally, setting the WOTP bit starts the
OTP programming.
confi guration data from the corresponding OTP byte
(RSELx=0) or the REG byte (RSELx=1). Changing an
RSELx bit immediately updates the chip confi guration.
the corresponding OTP byte (RSELx=0) or the REG byte
(RSELx=1).
corresponding RSEL bits set high.
PP
voltage should be considered failures and the
2
C logic and the CMDR register.
2
C reads return data from
PP
voltage is too
Table 1: LT3582 Series Register Map
OTP0/REG0 & OTP1/REG1: Data in addresses 00h &
01h is used to set the output voltages of the Boost and
Inverting converters respectively. See Setting the Output
Voltages for more information.
ADDRESS
LT3582/LT3582-5/LT3582-12
REGIS-
TER
00h
02h
04h
01h
REGIS-
NAME
REG0/
REG1/
REG2/
CMDR
OTP0
OTP1
OTP2
TER
BIT
7:0
7:0
4:3
1:0
7
6
5
2
7
6
5
4
3
2
1
0
SWOFF Switches-Off
PUSEQ Power-Up Sequencing: 00 =
RSEL2 Register Select 2 (0=OTP2,
RSEL0 Register Select 0 (0=OTP0,
NAME
PDDIS Power-Down Discharge Enable.
WOTP Write OTP Memory
FAULT
RSEL1 Register Select 1 (0=OTP1,
V
LOCK
IRMP
RST
BIT
PLUS
CF/
V
V
-
-
P
N
DESCRIPTION
V
BFh = 12.75V)
V
FFh = 13.95V)
Reserved, Write to 0
Lockout Bit: See “OTP Program-
ming Lockout” Section.
V
crease V
RAMPP & RAMPN Pullup Cur-
rent: I
PUSEQ Must be 11 if Set.
Outputs Disabled, 01 = V
Ramp 1st, 10 = V
11 = Both Ramp Together
Clear Fault/OTP Programming
Fault
Reset
Reserved, Write to 0
1=REG2)
1=REG1)
1=REG0)
OUTP
OUTN
OUTP
RAMP
Output Voltage (00h=3.2V,
Output Voltage (00h=1.2V,
Output Voltage Bit: In-
OUTP
= (2)
by ~25mV
OUTP
IRMP
Ramp 1st,
μA
13
3582512f
OUTN