19-1439; Rev 2; 4/04
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
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 logiccontrolled 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 VIN),
refer to the MAX868. The MAX860/MAX861 and MAX868
are available in space-saving µMAX packages.
Features
♦ 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)
Ordering Information
PART
TEMP RANGE
PINPACKAGE
SOT
TOP MARK
MAX1719EUT
Applications
Local Negative Supply from a Positive Supply
-40°C to +85°C
6 SOT23-6
AACA
MAX1720EUT
-40°C to +85°C
6 SOT23-6
AABS
MAX1721EUT
-40°C to +85°C
6 SOT23-6
AABT
Small LCD Panels
GaAs PA Bias Supply
Handy-Terminals, PDAs
Battery-Operated Equipment
Pin Configuration
Typical Operating Circuit
1µF
INPUT
1.5V to 5.5V
TOP VIEW
C1OUT
IN
MAX1721
OUT
IN
NEGATIVE
OUTPUT
-1 · VIN
25mA
OFF
2
3
6
5
SHDN (SHDN)
4
MAX1719
MAX1720
MAX1721
C1+
GND
1µF
SHDN
ON
1
C1-
C1+
GND
SOT23-6
( ) ARE FOR MAX1719
________________________________________________________________ Maxim Integrated Products
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.
1
MAX1719/MAX1720/MAX1721
General Description
