MAX8556_09 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – 4A Ultra-Low-Input-Voltage LDO Regulators

19-3257; Rev 2; 8/09
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4A Ultra-Low-Input-Voltage
LDO Regulators
General Description
The MAX8556/MAX8557 low-dropout linear regulators
operate from input voltages as low as 1.425V and are
able to deliver up to 4A of continuous output current
with a typical dropout voltage of only 100mV. The out-
put voltage is adjustable from 0.5V to V_IN - 0.2V.
Designed with an internal p-channel MOSFET pass tran-
sistor, the MAX8556/MAX8557 maintain a low 800µA typi-
cal supply current, independent of the load current and
dropout voltage. Using a p-channel MOSFET eliminates
the need for an additional external supply or a noisy inter-
nal charge pump. Other features include a logic-con-
trolled shutdown mode, built-in soft-start, short-circuit
protection with foldback current limit, and thermal-over-
load protection. The MAX8556 features a POK output that
transitions high when the regulator output is within ±10%
of its nominal output voltage. The MAX8557 offers a
power-on reset output that transitions high 140ms after the
output has achieved 90% of its nominal output voltage.
The MAX8556/MAX8557 are available in a 16-pin thin
QFN 5mm x 5mm package with exposed paddle.
Applications
Servers and Storage Devices
Networking
Base Stations
Optical Modules
Point-of-Load Supplies
ATE
Typical Operating Circuit
Features
o 1.425V to 3.6V Input Voltage Range
o Guaranteed 4A Output Current
o ±1% Output Accuracy Over Load/Line/
Temperature
o 100mV Dropout at 4A Load (typ)
o Built-In Soft-Start
o 800µA (typ) Operating Supply Current
o 150µA (max) Shutdown Supply Current
o Short-Circuit Current Foldback Protection
o Thermal-Overload Protection
o ±10% Power-OK (MAX8556)
o 140ms Power-On Reset Output (MAX8557)
o Fast Transient Response
o 16-Pin Thin QFN (5mm x 5mm) Package
Ordering Information
PART
TEMP PIN-
RANGE PACKAGE
FEATURE
MAX8556ETE+ -40°C to +85°C 16 Thin QFN-EP* POK
MAX8556ETE/V+ -40°C to +85°C 16 Thin QFN-EP* POK
MAX8557ETE+ -40°C to +85°C 16 Thin QFN-EP* POR
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V Denotes an automotive qualified part.
*EP = Exposed pad.
Pin Configuration
V_IN
1.425V TO 3.6V
V_OUT
0.5V TO V_IN - 0.2V
IN
OUT
MAX8556
EN ^(MAX8557) FB
POK
(POR)
GND
N.C.
TOP VIEW
FB 13
GND 14
N.C. 15
EN 16
+
12 11 10 9
MAX8556
(MAX8557)
EP
1234
8 OUT
7 OUT
6 IN
5 IN
THIN QFN
5mm x 5mm
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.