MAX1674 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – High-Efficiency, Low-Supply-Current, Compact, Step-Up DC-DC Converters

19-1360; Rev 3; 3/00
High-Efficiency, ^{EVFAOLLULAOTWIOSNDKAITTAMSAHNEUEATL} Low-Supply-Current,
Compact, Step-Up DC-DC Converters
General Description
The MAX1674/MAX1675/MAX1676 compact, high-effi-
ciency, step-up DC-DC converters fit in small µMAX
packages. They feature a built-in synchronous rectifier,
which improves efficiency and reduces size and cost
by eliminating the need for an external Schottky diode.
Quiescent supply current is only 16µA.
The input voltage ranges from 0.7V to V_OUT, where
V_OUT can be set from 2V to 5.5V. Start-up is guaran-
teed from 1.1V inputs. The MAX1674/MAX1675/
MAX1676 have a preset, pin-selectable output for 5V or
3.3V. The outputs can also be adjusted to other volt-
ages using two external resistors.
All three devices have a 0.3Ω N-channel MOSFET
power switch. The MAX1674 has a 1A current limit. The
MAX1675 has a 0.5A current limit, which permits the
use of a smaller inductor. The MAX1676 comes in a
10-pin µMAX package and features an adjustable cur-
rent limit and circuitry to reduce inductor ringing.
________________________Applications
Pagers
Wireless Phones
Medical Devices
Hand-Held Computers
PDAs
RF Tags
1 to 3-Cell Hand-Held Devices
Typical Operating Circuit
INPUT
0.7V TO V_OUT
ON
OFF
SHDN
LX
MAX1674 _OUT
MAX1675
OUTPUT
3.3V, 5V, OR
ADJ (2V TO 5.5V)
UP TO 300mA
LOW-BATTERY
DETECT IN
LBI
REF
0.1µF
LBO
FB GND
LOW-BATTERY
DETECT OUT
____________________________Features
o 94% Efficient at 200mA Output Current
o 16µA Quiescent Supply Current
o Internal Synchronous Rectifier (no external diode)
o 0.1µA Logic-Controlled Shutdown
o LBI/LBO Low-Battery Detector
o Selectable Current Limit for Reduced Ripple
o Low-Noise, Anti-Ringing Feature (MAX1676)
o 8-Pin and 10-Pin µMAX Packages
o Preassembled Evaluation Kit (MAX1676EVKIT)
_______________Ordering Information
PART
MAX1674EUA
MAX1675EUA
MAX1676EUB
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 µMAX
8 µMAX
10 µMAX
TOP VIEW
Pin Configurations
FB 1
LBI 2
LBO 3
REF 4
MAX1674
MAX1675
8 OUT
7 LX
6 GND
5 SHDN
µMAX
FB 1
LBI 2
LBO 3
CLSEL 4
REF 5
MAX1676
µMAX
10 OUT
9 LX
8 GND
7 BATT
6 SHDN
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