Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - DC/DC voltage regulator Switched-capacitor voltage converter SOT 23 6

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

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 (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

GND

C1-

C1+

OUT

( ) ARE FOR MAX1719

SOT23-6

SHDN (SHDN)

MAX1719

MAX1720

MAX1721

Pin Configuration

C1+ C1-

SHDN

OUT

GND

1µF

OFF

INPUT

1.5V to 5.5V

NEGATIVE

OUTPUT

-1 · V

25mA

MAX1721

Typical Operating Circuit

19-1439; Rev 2; 4/04

PART

MAX1719EUT

-40°C to +85°C

TEMP RANGE

PIN-

PACKAGE

6 SOT23-6

Ordering Information

SOT

TOP MARK

AACA

MAX1721EUT

-40°C to +85°C 6 SOT23-6 AABT

MAX1720EUT

-40°C to +85°C 6 SOT23-6 AABS

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.

Summary of content (8 pages)

PAGE 1
9-1439; 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.
PAGE 2
MAX1719/MAX1720/MAX1721 SOT23, Switched-Capacitor Voltage Inverters with Shutdown ABSOLUTE MAXIMUM RATINGS IN to GND .................................................................-0.3V to +6V OUT to GND .............................................................-6V to +0.3V C1+, SHDN, SHDN to GND .........................-0.3V to (VIN + 0.3V) C1- to GND...............................................(VOUT - 0.3V) to +0.3V OUT Output Current..........................................................
PAGE 3
SOT23, Switched-Capacitor Voltage Inverters with Shutdown (V IN = +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF (MAX1719/MAX1721), circuit of Figure 1, TA = -40°C to +85°C, unless otherwise noted.
PAGE 4
Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = C3, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. INPUT VOLTAGE MAX1719/ MAX1721 30 MAX1720 250 -40°C 150 MAX1720 -40°C 50 10 2.0 2.5 3.0 3.5 4.0 4.5 5.0 +85°C 0 1.5 5.5 2.0 2.5 INPUT VOLTAGE (V) FREQUENCY (kHz) VIN = +2V 40 VIN = +3.3V 30 35 5.0 60 MAX1720/21toc06 VIN = +1.
PAGE 5
SOT23, Switched-Capacitor Voltage Inverters with Shutdown MAX1719/MAX1721 OUTPUT VOLTAGE RIPPLE vs. CAPACITANCE MAX1719/MAX1721 OUTPUT CURRENT vs. CAPACITANCE VIN = +4.75V, VOUT = -4.0V VSHDN 5V/div OUTPUT CURRENT (mA) 30 VOUT 2V/div MAX1720/21toc14 35 25 VIN = +3.15V, VOUT = -2.5V 20 15 10 VIN = +1.9V, VOUT = -1.5V 5 350 300 VIN = +4.75V, VOUT = -4.0V 250 200 VIN = +3.15V, VOUT = -2.5V 150 VIN = +1.9V, VOUT = -1.
PAGE 6
MAX1719/MAX1720/MAX1721 SOT23, Switched-Capacitor Voltage Inverters with Shutdown f C1 1µF (10µF) INPUT 1.5V to 5.5V 2 6 C1+ 5 3 C1- IN OUT C3 1µF (10µF) ON OFF V+ 1 RL MAX1719* MAX1721 SHDN NEGATIVE OUTPUT -1 · VIN 25mA C2 C1 RL C2 1µF (10µF) Figure 3a. Switched-Capacitor Model GND 4 REQUIV V+ NOTE: ( ) CAPACITORS ARE FOR MAX1720. *ON/OFF POLARITY OF SHDN IS REVERSED FOR MAX1719. VOUT 1 REQUIV = f × C1 Figure 1. Typical Application Circuit S1 VOUT C2 RL S2 IN Figure 3b.
PAGE 7
SOT23, Switched-Capacitor Voltage Inverters with Shutdown … 2 3 4 C1 6 Output Capacitor (C2) Increasing the output capacitor’s value reduces the output ripple voltage. Decreasing its ESR reduces both output resistance and ripple. Lower capacitance values can be used with light loads if higher output ripple can be tolerated.
PAGE 8
MAX1719/MAX1720/MAX1721 SOT23, Switched-Capacitor Voltage Inverters with Shutdown 2 3 C1 4 6 SHDN (MAX1719) SHDN (MAX1720/ MAX1721) MAX1719 MAX1720 MAX1721 “1” SHDN (MAX1719) SHDN (MAX1720) (MAX1721) … +VIN 2 3 4 C1 1 6 … 5 +VIN 5 3 MAX1719 MAX1720 MAX1721 “n” C1 1 4 VOUT 6 D1, D2 = 1N4148 2 MAX1719 MAX1720 MAX1721 D1 1 VOUT = -VIN 5 VOUT = -VIN C2 D2 C2 RO OF SINGLE DEVICE RO = NUMBER OF DEVICES C4 C3 Figure 5.