POWER MANAGEMENT
Description
The SC1454 contains two ultra low dropout voltage
regulators (ULDOs). It operates from an input voltage
range of 2.25V to 6.5V, and a wide variety of output
voltage options are available. One ULDO has a fixed
output, and the other is either fixed (SETA pin grounded)
or adjustable using external resistors. Each ULDO has an
independent enable pin.
Dual 150mA Ultra Low
Dropout, Low Noise Regulator
Features
Up to 150mA per regulator output
Low quiescent current
Low dropout voltage
Stable operation with ceramic caps
Very low 50碌V
RMS
output noise
Wide selection of output voltages
Tight load and line regulation
Current and thermal limiting
Reverse input polarity protection
<1.5uA off-mode current
Logic controlled enable
SC1454
Designed specifically for battery operated systems, the
devices utilize CMOS technology to require very low
operating currents (typically 130碌A(chǔ) with both outputs
supplying 150mA). In addition, the dropout voltage is
typically 155mV at 150mA, helping to prolong battery
life further. The devices are designed to provide 400mA
of peak current for applications which require high initial
inrush current.
They have been designed to be used with low ESR
ceramic capacitors to save cost and PCB area.
The SC1454 is available with a wide variety of voltage
options as standard. It comes in the tiny 8 lead MSOP
surface mount package.
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The SC1454 has a bypass pin to enable the user to
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capacitively decouple the bandgap reference for very low
u
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output noise (50碌V
RMS
typically).
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Applications
Cellular telephones
Palmtop/Laptop computers
Battery-powered equipment
Bar code scanners
SMPS post regulator/dc to dc modules
High efficiency linear power supplies
Typical Application Circuit
U1 SC1454DIMS
OUTPUT A: 3.0V
OUTPUT B: 3.0V
1
2
3
4
C1
1uF
C2
1uF
OUTA
OUTB
GND
SETA
IN
ENA
BYP
ENB
8
7
6
5
C3
10nF
ENABLE OUTPUT B
C4
1uF
VIN
ENABLE OUTPUT A
U1
OUTPUT A: 2.5V
OUTPUT B: 2.8V
R1
100k
1
2
3
4
SC1454CIMS
IN
ENA
BYP
ENB
8
7
6
5
ENABLE OUTPUT B
VIN
ENABLE OUTPUT A
OUTA
OUTB
GND
SETA
R2
100k
C1
1uF
C2
1uF
C3
10nF
C4
1uF
Revision 1, November 2000
1
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