SC1454_05 Datasheet, PDF (1/14 Pages) Semtech Corporation – Dual 150mA Ultra Low Dropout, Low Noise Regulator

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.
The SC1454 has a bypass pin to enable the user to
capacitively decouple the bandgap reference for very low
output noise (50µV_RMS typically).
Designed specifically for battery operated systems, the
devices utilize CMOS technology to require very low
operating currents (typically 130µA 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.
SC1454
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 50µV_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
Applications
‹ Cellular telephones
‹ Palmtop/Laptop computers
‹ Battery-powered equipment
‹ Bar code scanners
‹ SMPS post regulator/dc to dc modules
‹ High efficiency linear power supplies
The SC1454 is available with a wide variety of voltage
options as standard. It comes in the tiny 8 lead MSOP
surface mount package.
Typical Application Circuit
OUTPUT A: 3.0V
OUTPUT B: 3.0V
C1
C2
1uF
1uF
U1 SC1454DIMS
1 _OUTA
IN ⁸
2 _OUTB
ENA ⁷
3 _GND
BYP ⁶
4 _SETA
ENB ⁵
C3
10nF
VIN
ENABLE OUTPUT A
ENABLE OUTPUT B
C4
1uF
OUTPUT A: 2.5V
OUTPUT B: 2.8V
R1
100k
R2
100k
C1
C2
1uF
1uF
U1 SC1454CIMS
1 _OUTA
IN ⁸
2 _OUTB
ENA ⁷
3 _GND
BYP ⁶
4 _SETA
ENB ⁵
VIN
ENABLE OUTPUT A
ENABLE OUTPUT B
C3
C4
10nF
1uF
Revision: May 4, 2005
1
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