Rainbow Electronics MAX1721 - Manual

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
· V
IN
),
refer to the MAX868. The MAX860/MAX861 and MAX868
are available in space-saving µMAX packages.
Applications
Local Negative Supply from a Positive Supply
Small LCD Panels
GaAs PA Bias Supply
Handy-Terminals, PDAs
Battery-Operated Equipment
Features
♦
1nA Logic-Controlled Shutdown
♦
6-Pin SOT23 Package
♦
99.9% Voltage Conversion Efficiency
♦
50µA Quiescent Current (MAX1719 / MAX1720)
♦
+1.5V to +5.5V Input Voltage Range
♦
25mA Output Current
♦
Requires Only Two 1µF Capacitors
(MAX1719/MAX1721)
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
________________________________________________________________ Maxim Integrated Products 1
TOP VIEW
IN
GND C1-
C1+ OUT
( ) ARE FOR MAX1719
SOT23-6
1 6
SHDN (SHDN) 5
MAX1719
MAX1720
MAX1721
2
3 4
Pin Configuration
C1+ C1-
IN
SHDN
OUT
GND
ON
1 µ F
1 µ F
OFF
INPUT
1.5V to 5.5V
NEGATIVE
OUTPUT
-1
· V
IN
25mA
MAX1721
Typical Operating Circuit
19-1439; Rev 1; 5/99
PART
MAX1719 EUT -40°C to +85°C
TEMP. RANGE
PIN-
PACKAGE
6 SOT23-6
Ordering Information
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
SOT
TOP MARK
AACA
MAX1721 EUT -40°C to +85°C 6 SOT23-6 AABT
MAX1720 EUT -40°C to +85°C 6 SOT23-6 AABS