Rainbow Electronics MAX1706 - Manual

_______________General Description
The MAX1705/MAX1706 are high-efficiency, low-noise,
step-up DC-DC converters with an auxiliary linear-
regulator output. These devices are intended for use in
battery-powered wireless applications. They use a syn-
chronous rectifier pulse-width-modulation (PWM) boost
topology to generate 2.5V to 5.5V outputs from battery
inputs, such as 1 to 3 NiCd/NiMH cells or 1 Li-Ion cell.
The MAX1705 has an internal 1A N-channel MOSFET
switch. The MAX1706 has a 0.5A switch. Both devices
also have a built-in low-dropout linear regulator that
delivers up to 200mA.
With an internal synchronous rectifier, the MAX1705/
MAX1706 deliver 5% better efficiency than similar non-
synchronous converters. They also feature a pulse-
frequency-modulation (PFM) standby mode to improve
efficiency at light loads, and a 1µA shutdown mode. An
efficiency-enhancing track mode reduces the step-up
DC-DC converter output to 300mV above the linear-reg-
ulator output.
Both devices come in a 16-pin QSOP package, which
occupies the same space as an 8-pin SO. Other features
include two shutdown-control inputs for push-on/push-off
control, and an uncommitted comparator for use as a volt-
age monitor.
________________________Applications
Digital Cordless Phones PCS Phones
Personal Communicators Wireless Handsets
Palmtop Computers Two-Way Pagers
Hand-Held Instruments
____________________________Features
♦ Up to 96% Efficiency
♦ 1.1V IN Guaranteed Start-Up
♦ Up to 850mA Output (MAX1705)
♦ Step-Up Output (2.5V to 5.5V adjustable)
♦ Linear Regulator (1.25V to 5.0V adjustable)
♦ PWM/PFM Synchronous-Rectified Topology
♦ 300kHz PWM Mode or Synchronizable
♦ 1µA Shutdown Mode
♦ Voltage Monitor
♦ Pushbutton On/Off Control
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
________________________________________________________________ Maxim Integrated Products 1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
LBP POUT
ONA
ONB
LX
PGND
CLK/SEL
LBO
LDO
TOP VIEW
MAX1705
MAX1706
QSOP
LBN
REF
OUT
TRACK
GND
FB
FBLDO
__________________Pin Configuration
LX
POUT
OUT
STEP-UP OUTPUT
FB
CLK/SEL
ONA
ONB
TRACK
INPUT 0.7V TO 5.5V
PGND GND
LDO
FBLDO
LBP
LBO
LBN
REF
MAX1705
MAX1706
LINEAR
REGULATOR
OUTPUT
LOW-BATTERY
DETECTION
ON/OFF CONTROL
HIGH
EFFICIENCY
LOW
NOISE
__________Typical Operating Circuit
19-1198; Rev 0; 4/97
PART
MAX1705 C/D
MAX1705EEE
MAX1706 C/D 0°C to +70°C
-40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
Dice*
16 QSOP
Dice*
EVALUATION KIT MANUAL
AVAILABLE
______________Ordering Information
* Dice are tested at T A = +25°C, DC parameters only.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX1706EEE -40°C to +85°C 16 QSOP