19-4488; Rev 0; 3/09
1.425V to 3.6V Input, 1A Low-Dropout
Regulators with BIAS Input
7/MAX15028
General Description
Features
The MAX15027/MAX15028 low-dropout linear regulators
operate from input voltages as low as 1.425V and deliver
up to 1A of continuous output current with a typical
dropout voltage of only 75mV. The output voltage is
o 1.425V to 3.6V Input Voltage Range
o Output Voltage Programmable from 0.5V to V
IN
o Guaranteed Maximum 225mV Dropout at 1A
Output Current
adjustable from 0.5V to V and is 2ꢀ accurate over load
IN
and line variations, from -40°C to +125°C. The MAX15028
features a BIAS input of 3V to 5.5V from an always-on
power supply. The BIAS input current is reduced down to
less than 2µA during shutdown.
o
2ꢀ Output Aꢁꢁuraꢁc Oꢂer ꢃoadꢄ ꢃineꢄ and
Temperature
o Stable with Ceramiꢁ Capaꢁitors
o Fast Transient Response
These regulators use small, 1µF ceramic input capaci-
tors and 4.7µF ceramic output capacitors to deliver 1A
output current. High bandwidth provides excellent tran-
sient response and limits the output voltage deviation to
15mV for a 500mA load step, with only a 4.7µF ceramic
output capacitor, and the voltage deviations can be
reduced further by increasing the output capacitor.
o 60µA Operating Bias Supplc Current (MAX15028)
o 1.2µA Shutdown Bias Supplc Current (MAX15028)
o Short-Cirꢁuit and Thermal Proteꢁtion
o -40°C to +125°C Operating Temperature Range
o Soft-Start ꢃimits Inrush Current
These devices offer a logic-controlled shutdown input
to reduce input current (I ) consumption down to less
IN
o Thermallc Enhanꢁed 3mm x 3mm TDFN Paꢁkage
than 5.5µA in standby mode. Other features include a
soft-start to reduce inrush current, short-circuit protec-
tion, and thermal-overload protection.
Ordering Information
PIN-
PACKAGE
TOP
MARK
The MAX15028 features a BIAS input allowing a sec-
ondary supply to keep the LDO’s internal circuitry alive
if the voltage on IN goes to 0V. Both devices are fully
specified from -40°C to +125°C and are available in a
10-pin thermally enhanced TDFN package (3mm x
3mm) that includes an exposed pad for optimal power
dissipation. For a 500mA version of these LDOs, refer
to the MAX15029/MAX15030 data sheet.
PART
TEMP RANGE
MAX15027ATB+T -40°C to +125°C 10 TDFN-EP* +AUD
MAX15028ATB+T -40°C to +125°C 10 TDFN-EP* +AUE
+Denotes a lead(Pb)-free and RoHS-compliant package.
For tape-and-reel orders, add a “T” after the “+”.
*EP = Exposed pad.
Applications
Pin Configurations
Automotive (Dead-Man LDO)
Servers
TOP VIEW
Storage
Networking
+
IN
IN
1
2
3
4
5
10 OUT
Base Stations
Optical Modules
ATE
9
8
7
6
OUT
GND
FB
IN
MAX15027
I.C.
EN
SS
TDFN
(3mm x 3mm)
Tcpiꢁal Operating Cirꢁuits appear at end of data sheet.
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Produꢁts
1
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or ꢂisit Maxim’s website at www.maxim-iꢁ.ꢁom.