Rainbow Electronics MAX1703 - Manual

________________General Description
The MAX1703 is a high-efficiency, low-noise, step-up
DC-DC converter intended for use in battery-powered
wireless applications. It uses a synchronous-rectified
pulse-width-modulation (PWM) boost topology to gen-
erate a 2.5V to 5.5V output from battery inputs, such as
one to three NiCd/NiMH cells or one Li-Ion cell. The
device includes a 2A, 75m
Ω
, N-channel MOSFET
switch and a 140m
Ω
, P-channel synchronous rectifier.
With its internal synchronous rectifier, the MAX1703
delivers up to 5% better efficiency than similar nonsyn-
chronous converters. It also features a pulse-frequency-
modulation (PFM) low-power mode to improve efficiency
at light loads, and a 1µA shutdown mode.
The MAX1703 comes in a 16-pin narrow SO package
and includes an uncommitted comparator that generates
a power-good or low-battery-warning output. It also
contains a linear gain block that can be used to build a
linear regulator.
For lower-power outputs and a smaller package, refer
to the MAX1700/MAX1701. For dual outputs (step-up
plus linear regulator), refer to the MAX1705/MAX1706.
For an on-board analog-to-digital converter, refer to the
MAX848/MAX849.
The MAX1703 evaluation kit is available to speed designs.
____________________________Features
♦ Up to 95% Efficiency
♦ Up to 1.5A Output
♦ Fixed 5V or Adjustable Step-Up Output
(2.5V to 5.5V)
♦ 0.7V to 5.5V Input Range
♦ Low-Power Mode (300µW)
♦ Low-Noise, Constant-Frequency Mode (300kHz)
♦ Synchronizable Switching Frequency
(200kHz to 400kHz)
♦ 1µA Logic-Controlled Shutdown
♦ Power-Good Comparator
♦ Uncommitted Gain Block
________________________Applications
Digital Cordless Phones Personal Communicators
PCS Phones Palmtop Computers
Wireless Handsets Hand-Held Instruments
Two-Way Pagers
MAX1703
1-Cell to 3-Cell, High-Power (1.5A),
Low-Noise, Step-Up DC-DC Converter
________________________________________________________________ Maxim Integrated Products 1
19-1336; Rev 2; 11/98
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
Ordering Information
Typical Operating Circuit
PART TEMP. RANGE PIN-PACKAGE
MAX1703ESE -40°C to +85°C 16 Narrow SO
PGND GND FB
POUT
OUT
LXP, LXN OFF
INPUT
0.7V TO 5.5V
OR
ON
SYNC
PWM
PFM
OUTPUT
5V OR ADJ
UP TO 1.5A
CLK/
SEL
ON
POKIN
POK
AO
AIN
REF
POWER-GOOD
INPUT
POWER-GOOD
OUTPUT
GAIN-BLOCK INPUT
GAIN-BLOCK
OUTPUT
MAX1703
Pin Configuration
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
REF ON
POUT
LXP
POUT
PGND
LXN
PGND
CLK/SEL
TOP VIEW
MAX1703
Narrow SO
FB
POKIN
AIN
OUT
GND
AO
POK
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.