MAX1572 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – 800mA, 2MHz, PWM DC-to-DC Step-Down Converter with RESET

19-2837; Rev 0; 4/03
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800mA, 2MHz, PWM DC-to-DC
Step-Down Converter with RESET
General Description
The MAX1572 is a fixed-frequency, synchronous step-
down DC-to-DC converter to power low-voltage micro-
processor/DSP cores in portable equipment requiring
high efficiency in a limited PC board area. The features
are optimized for high efficiency over a wide load range,
small external component size, low output ripple, and
excellent transient response. The input supply voltage
range is from 2.6V to 5.5V, while the output is internally
fixed from 0.75V to 2.5V in 50mV increments with a
guaranteed output current of 800mA. The high 2MHz
switching allows tiny low-cost capacitors and a low-pro-
file inductor, while the power-saving pulse-group mode
reduces quiescent current to 48µA (typ) with light loads.
To reduce noise and RF interference, the converter can
be configured to provide forced-PWM operation.
The MAX1572 includes a low on-resistance internal
MOSFET switch and synchronous rectifier to maximize
efficiency and minimize external component count. No
external diode is needed. Other features include soft-
start to eliminate inrush current at startup and a 170ms
(min) RESET output to provide power-on/undervoltage
reset. The MAX1572 is available in a 12-pin, 4mm x
4mm thin QFN package with exposed paddle.
Applications
Cell Phones and Smart Phones
PDAs, Palmtops, and Notebook Computers
MP3 and DVD Players
Digital Cameras and Camcorders
PCMCIA Cards
Hand-Held Instruments
Selector Guide appears at end of data sheet.
Typical Operating Circuit
INPUT
2.6V TO 5.5V
BATT
OUTPUT
0.75V TO 2.5V
2.2µH
800mA
LX
MAX1572
ABATT
PGND
MODE
SELECT
EN1
OUT
EN2
RESET
SS
GND
Features
o Up to 97% Efficiency
o 2MHz PWM Switching
o 800mA Guaranteed Output Current
o Low 48µA Quiescent Current
o Power-Saving Modes: Pulse-Group, Pulse-Skip,
Forced-PWM Mode
o 0.75V to 2.5V Preset Output Range
(in 50mV Increments)
o Voltage-Positioning Load Transients
o 5mV_P-P Output Ripple
o Tiny 2.2µH Inductor
o 10µF Ceramic Output Capacitor
o Low 0.1µA Shutdown Current
o No External Schottky Diode Required
o Soft-Start with Zero Inrush Current
o 170ms (min) RESET Output
o Small 12-Pin, 4mm x 4mm Thin QFN Package
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX1572ETC075 -40°C to +85°C 12 Thin QFN-EP**
MAX1572ETC130 -40°C to +85°C 12 Thin QFN-EP**
MAX1572ETC150 -40°C to +85°C 12 Thin QFN-EP**
MAX1572ETC180 -40°C to +85°C 12 Thin QFN-EP**
MAX1572ETC250 -40°C to +85°C 12 Thin QFN-EP**
MAX1572ETCxyz* -40°C to +85°C 12 Thin QFN-EP**
*xyz is for the output voltage (e.g., MAX1572ETC165 has a
1.65V output). Minimum order quantity is 2500.
**EP = Exposed paddle.
Pin Configuration
TOP VIEW
987
EN1 10
GND 11
ABATT ¹²
MAX1572
123
6 EN2
5 GND
4 OUT
4mm x 4mm
THIN QFN
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