MAX15104 Datasheet, PDF (7/10 Pages) Maxim Integrated Products – Small 2A, Low-Dropout Linear Regulator in a 2.7mm x 1.6mm Package

MAX15104
Small 2A, Low-Dropout Linear Regulator
in a 2.7mm x 1.6mm Package
Functional Diagram
IN
THERMAL-
OVERLOAD
PROTECTION
EN
SHUTDOWN
LOGIC
0.60V
g_M
0.55V
REF
0.65V
GND
MAX15104
SS_BYP
UNDERVOLTAGE
LOCKOUT
ERROR
AMPLIFIER
ILIM
PG
CIRCUITRY
P
OUT
FB
PG
N
Detailed Description
The MAX15104 is a small, low-dropout linear regulator
optimized for server, network, and telecom applications.
The regulator delivers up to 3A from a 1.7V to 5.5V input
supply with output accuracy of Q1.6%. The output is
adjustable down to 0.6V with a guaranteed dropout volt-
age of less than 150mV at full load. The internal p-chan-
nel switch is protected with a foldback current limit and
thermal shutdown.
The MAX15104 features an external bypass input to
reduce noise. This bypass input also serves as a soft-
start control. An enable input and power-good output are
included for power sequence control.
Internal p-Channel Pass Transistor
The MAX15104 features a 2A p-channel MOSFET pass
transistor. Unlike similar designs with pnp pass transistors,
the gate-drive current to the p-channel power transistor is
extremely low. PNP-based regulators also waste consider-
able current in dropout when the pass transistor saturates
and uses high base-drive currents under large loads. The
MAX15104 does not suffer from these deficiencies and
consumes only 1.8mA of quiescent current even in dropout.
Output Voltage Selection
The MAX15104 features an adjustable output. The out-
put voltage can be set between +0.6V to VIN - 200mV
using an external resistive voltage-divider to FB (see
the Typical Operating Circuit). The output voltage is set
using the following equation:
V_OUT = V_FB (1 + R1/R2)
where V_FB = +600mV.
To simplify resistor selection:
R1 = R2 (V_OUT/V_FB - 1)
Set R2 to 600I.
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