Rainbow Electronics MAX1790 User Manual

Max1790 low-noise step-up dc-dc converter, General description, Applications

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For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

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 0.21

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.

Applications

LCD Displays

PCMCIA Cards

Portable Applications

Hand-Held Devices

Features

90% Efficiency
Adjustable Output from V

IN

to 12V

1.6A, 0.21, 14V Power MOSFET
+2.6V to +5.5V Input Range
Pin-Selectable 640kHz or 1.2MHz Switching

Frequency

0.1µA Shutdown Current
Programmable Soft-Start
Small 8-Pin µMAX Package

MAX1790

Low-Noise Step-Up DC-DC Converter

________________________________________________________________ Maxim Integrated Products

1

IN

LX

GND

1

2

8

7

SS

FREQ

FB

COMP

µMAX

TOP VIEW

3

4

6

5

MAX1790

SHDN

LX

IN

V

IN

2.6V TO 5V

GND

FREQ

V

OUT

COMP

SHDN

FB

MAX1790

ON/OFF

SS

Typical Operating Circuit

19-1563; Rev 0a; 1/00

PART

MAX1790EUA

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

8 µMAX

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Pin Configuration

Ordering Information

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