LP3910SQ-AN Datasheet, PDF (45/60 Pages) National Semiconductor (TI) – Power Management IC for Hard Drive Based Portable Media Players

DC/DC Converters
OVERVIEW
The LP3910SQ-AN provides the DC/DC converters that sup-
ply the various power needs of the application by means of
SUPPLY SPECIFICATION
one BUCK-Boost (HDD driver), two Linear Low Drop Regu-
lators (LDO1, LDO2) and two BUCK converters (BUCK1,
BUCK2).
The table hereunder lists the output characteristics of the var-
ious regulators.
Supply
LDO1
LDO2
BUCK1
BUCK2
BUCK/BOOST
Load
various
analog
CPU, DSP
IO, Logic,
Memories
HDD
Default (V)
1.2
2.5
1.0
1.8
3.3
V_OUT (Volts)
Range (V)
1.2 to 3.3
1.3 to 3.3
0.8 to 2.0
1.8 to 3.3
1.8 to 3.3
Resolution (mV)
100
100
50
100
50
I_MAXMaximum Output
Current (mA)
150
150
600
600
1000
LINEAR LOW DROP-OUT REGULATORS (LDOS)
LDO1 is a regulator that can respond to fast transients and is slated for digital loads and high bandwidth analog loads. LDO2 is a
linear regulator with a similar architecture but has a slower transient response time with a lower noise performance to supply analog
loads. The output voltages of both LDOs are register programmable through the I²C interface. The default output voltages are
factory programmed during Final Test.
30101225
NO-LOAD STABILITY
The LDOs will remain stable and in regulation with no external load. This is an important consideration in some circuits, for example
CMOS RAM keep-alive applications.
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