19-1439; Rev 2; 4/04
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
General Description
The ultra-small MAX1719/MAX1720/MAX1721 monolithic,
CMOS charge-pump inverters accept input voltages
ranging from +1.5V to +5.5V. The MAX1720 operates at
12kHz, and the MAX1719/MAX1721 operate at 125kHz.
High efficiency, small external components, and logic-
controlled shutdown make these devices ideal for both
battery-powered and board-level voltage conversion
applications.
Oscillator control circuitry and four power MOSFET
switches are included on-chip. A typical MAX1719/
MAX1720/MAX1721 application is generating a -5V
supply from a +5V logic supply to power analog circuitry.
All three parts come in a 6-pin SOT23 package and can
deliver a continuous 25mA output current.
For pin-compatible SOT23 switched-capacitor voltage
inverters without shutdown (5-pin SOT23), see the
MAX828/MAX829 and MAX870/MAX871 data sheets. For
applications requiring more power, the MAX860/MAX861
deliver up to 50mA. For regulated outputs (up to -2 x V
IN
),
refer to the MAX868. The MAX860/MAX861 and MAX868
are available in space-saving µMAX packages.
♦
1nA Logic-Controlled Shutdown
♦
6-Pin SOT23 Package
♦
99.9% Voltage Conversion Efficiency
♦
50µA Quiescent Current (MAX1720)
♦
+1.5V to +5.5V Input Voltage Range
♦
25mA Output Current
♦
Requires Only Two 1µF Capacitors
(MAX1719/MAX1721)
Features
MAX1719/MAX1720/MAX1721
Ordering Information
PART
MAX1719EUT
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
SOT
TOP MARK
AACA
AABS
AABT
Applications
Local Negative Supply from a Positive Supply
Small LCD Panels
GaAs PA Bias Supply
Handy-Terminals, PDAs
Battery-Operated Equipment
MAX1720EUT
MAX1721EUT
Typical Operating Circuit
1µF
Pin Configuration
TOP VIEW
INPUT
1.5V to 5.5V
C1+
IN
C1-
OUT
NEGATIVE
OUTPUT
-1
·
V
IN
25mA
1µF
OUT
1
6
C1+
IN
2
MAX1721
ON
OFF
SHDN
GND
MAX1719
MAX1720
MAX1721
5
SHDN (SHDN)
C1-
3
4
GND
SOT23-6
( ) ARE FOR MAX1719
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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