Rainbow Electronics MAX679 - Manual

_______________General Description
The MAX679 step-up, regulated charge pump gener-
ates a 3.3V ±4% output voltage from a 1.8V to 3.6V
input voltage (two alkaline, NiCd, or NiMH; or one
Lithium-Ion battery). Output current is 20mA (min) from
a 2.0V input. Only three external capacitors are needed
to build a complete DC-DC converter.
The MAX679’s switching frequency is pin selectable at
330kHz or 1MHz to allow trade-offs between lowest
supply current and smallest-size capacitors. The logic
shutdown function reduces the supply current to 5µA
(max) and disconnects the load from the input. Special
soft-start circuitry prevents excessive current from
being drawn from the battery during start-up. This DC-
DC converter requires no inductors and has low EMI. It
is available in the ultra-small µMAX package, which is
only 1.11mm high and half the area of an 8-pin SO.
________________________Applications
Battery-Powered Applications
Miniature Equipment
Backup-Battery Boost Converters
Translators
Two-Way Pagers
____________________________Features
♦ Regulated 3.3V ±4% Output
♦ Ultra-Small:
1.1mm-High, 8-Pin µMAX Package
♦ No Inductors Required
♦ Up to 1MHz Operation
(small external components)
♦ Fits into 0.05 in. 2
♦ Up to 85% Efficiency
♦ 1.8V to 3.6V Input Voltage Range
♦ 50µA Quiescent Supply Current
♦ 1µA Shutdown Current
MAX679
Regulated 3.3V Charge Pump
________________________________________________________________ Maxim Integrated Products 1
C1-
PGND GND
1
2
8
7
OUT
C1+ SHDN
IN
FSET
µ
MAX
TOP VIEW
3
4
6
5
MAX679
__________________Pin Configuration
MAX679
OUT
C1+
C1- OFF/ON
IN
FSET
SHDN
INPUT
2V to 3.6V
OUTPUT
3.3V, 20mA
C IN
C
OUT
C1
GND PGND
__________Typical Operating Circuit
19-1217; Rev 0; 4/97
PART
MAX679C/D 0°C to +70°C
TEMP. RANGE PIN-PACKAGE
Dice*
______________Ordering Information
* Dice are tested at T A = +25°C only.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX679EUA -40°C to +85°C 8 µMAX