MAX8833_09 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – Dual, 3A, 2MHz Step-Down Regulator

19-0725; Rev 2; 4/09
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Dual, 3A, 2MHz Step-Down Regulator
General Description
The MAX8833 high-efficiency, dual step-down regulator
is capable of delivering up to 3A at each output. The
device operates from a 2.35V to 3.6V supply, and pro-
vides output voltages from 0.6V to 0.9 x V_IN, making it
ideal for on-board point-of-load applications. Total output
error is less than ±1% over load, line, and temperature.
The MAX8833 operates in PWM mode with a switching
frequency ranging from 0.5MHz to 2MHz, set by an
external resistor. It can also be synchronized to an
external clock in the same frequency range. Two inter-
nal switching regulators operate 180° out-of-phase to
reduce the input ripple current, and consequently
reduce the required input capacitance. The high
operating frequency minimizes the size of external
components. High efficiency, internal dual-nMOS
design keeps the board cool under heavy loads. The
voltage-mode control architecture and the high-band-
width (> 15MHz typ) voltage-error amplifier allow a type
III compensation scheme to be utilized to achieve fast
response under both line and load transients, and also
allow for ceramic output capacitors.
Programmable soft-start reduces input inrush current.
Two enable inputs allow the turning on/off of each out-
put individually, resulting in great flexibility for system-
level designs. A reference input is provided to facilitate
output-voltage tracking applications. The MAX8833 is
available in a 32-pin thin QFN (5mm x 5mm) package
with 0.8mm max height.
Applications
ASIC/CPU/DSP Power Supplies
DDR Power Supplies
Set-Top Box Power Supplies
Printer Power Supplies
Network Power Supplies
Features
o 35mΩ On-Resistance Internal MOSFETs
o Dual, 3A, PWM Step-Down Regulators
o Fully Protected Against Overcurrent,
Short Circuit, and Overtemperature
o ±1% Output Accuracy over Load, Line,
and Temperature
o Operates from 2.35V to 3.6V Supply
o REFIN on One Channel for Tracking or
External Reference
o Integrated Boost Diodes
o Adjustable Output from 0.6V to 0.9 x V_IN
o Soft-Start Reduces Inrush Supply Current
o 0.5MHz to 2MHz Adjustable Switching,
or FSYNC Input
o All-Ceramic-Capacitor Design
o 180° Out-of-Phase Operation Reduces Input
Ripple Current
o Individual Enable Inputs and PWRGD Outputs
o Safe-Start into Prebiased Output
o Available in 5mm x 5mm Thin QFN Package
o Sink/Source Current in DDR Applications
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX8833ETJ+ -40°C to +85°C 32 Thin QFN (5mm x 5mm)
+Denotes a lead(Pb)-free/RoHS-compliant package.
Typical Operating Circuit
INPUT1
2.35V TO 3.6V
OUTPUT1
1.2V / 3A
IN1 IN2
BST1
BST2
LX1
LX2
INPUT2
2.35V TO 3.6V
OUTPUT2
1.5V / 3A
PGND1 PGND2
MAX8833
FB1
FB2
Pin Configuration appears at end of data sheet.
TYPE III
COMPENSATION
ON
OFF
COMP1 COMP2
PWRGD1 PWRGD2
EN1
EN2
GND
TYPE III
COMPENSATION
ON
OFF
________________________________________________________________ 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.