19-1563; Rev 0; 1/00
UAL
IT MAN
TION K
A
SHEET
EVALU
S DATA
W
FOLLO
Low-Noise Step-Up DC-DC Converter
Features
o
90% Efficiency
o
Adjustable Output from V
IN
to 12V
o
1.6A, 0.21Ω, 14V Power MOSFET
o
+2.6V to +5.5V Input Range
o
Pin-Selectable 640kHz or 1.2MHz Switching
Frequency
o
0.1µA Shutdown Current
o
Programmable Soft-Start
o
Small 8-Pin µMAX Package
General Description
The MAX1790 boost converter incorporates high-perfor-
mance (at 1.2MHz), current-mode, fixed-frequency, pulse-
width modulation (PWM) circuitry with a built-in 0.21Ω
N-channel MOSFET to provide a highly efficient regulator
with fast response.
High switching frequency (640kHz or 1.2MHz selectable)
allows easy filtering and faster loop performance. An
external compensation pin provides the user flexibility in
determining loop dynamics, allowing the use of small, low
equivalent series resistance (ESR) ceramic output capaci-
tors. The device can produce an output voltage as high as
12V from an input as low as 2.6V.
Soft-start is programmed with an external capacitor, which
sets the input current ramp rate. In shutdown mode, cur-
rent consumption is reduced to 0.1µA. The MAX1790 is
available in a space-saving 8-pin µMAX package. The
ultra-small package and high switching frequency allow
the total solution to be less than 1.1mm high.
MAX1790
Applications
LCD Displays
PCMCIA Cards
Portable Applications
Hand-Held Devices
PART
MAX1790EUA
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8 µMAX
Typical Operating Circuit
V
IN
2.6V TO 5V
Pin Configuration
TOP VIEW
IN
ON/OFF
SHDN
COMP
1
V
OUT
LX
8
7
SS
FREQ
IN
LX
FB
SHDN
2
MAX1790
3
6
5
MAX1790
FREQ
GND
GND
4
µMAX
SS
COMP
FB
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
