SC1458
Dual Output Low Noise LDO
Linear Regulator
POWER MANAGEMENT
Features
Description
Input voltage range — 2.5 to 5.5V
Output voltages — 2.8V and 1.8V (SC1458A), 2.85V
and 2.85V (SC1458B)
Maximum output current — 300mA (each LDO)
Low 200mV maximum dropout at 200mA load
Quiescent current — 100μA (both LDOs enabled)
Shutdown current — 100nA
Output noise < 50μVRMS (SC1458B)
PSRR > 65dB at 1kHz (SC1458B)
Space saving package — MLPD-W6, 3mm x 3mm
Over-temperature protection
The SC1458 is a family of dual output, ultra-low dropout
linear voltage regulators designed for use in battery
powered wireless applications. Both versions of the
SC1458 require an input voltage level between 2.5V and
5.5V. The SC1458A supplies 2.5V on OUTA and 1.8V on
OUTB, while SC1458B supplies 2.85V on both outputs.
(For other voltage options see the SC560).
TheSC1458AprovidesaPGOODoutputtoholdaprocessor
in reset when the voltage on OUTA is not in regulation.
The SC1458B provides superior low-noise performance by
using an external bypass capacitor to filter the bandgap
reference. Both versions have a single enable pin that
controls both LDO outputs. The startup sequence delays
the start of OUTB by 128ꢀs after OUTA is enabled.
Short-circuit protection
Under-voltage lockout
Reset monitor for output A (SC1458A)
Applications
Each version also provides protection circuitry such as
current limiting, under-voltage lockout, and thermal
protection to prevent device failures. Stability is
maintained by using 1ꢀF capacitors on the output pins.
The MLPD package and 0402 ceramic capacitors minimize
the required PCB area.
PDAs and cellular phones
GPS devices
Palmtop computers and handheld instruments
TFT/LCD applications
Wireless handsets
Digital cordless phones and PCS phones
Personal communicators
Two-way pagers
Wireless LAN
Typical Application Circuit
SC1458A
To μP
VIN
VIN
EN
PGOOD
OUTA
OUTA
2.5V, 300mA
From μP
OUTB
1.8V, 300mA
GND
OUTB
CIN
COUTA
COUTB
1μF
2.2μF
1μF
September 12, 2007
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