Maxim MAX1720EUT, MAX1719EUT, MAX1721EUT Datasheet

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 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 · VIN),
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

1µF

1µF

OFF

INPUT

1.5V to 5.5V

NEGATIVE
OUTPUT

-1 · V

IN

25mA

MAX1721

Typical Operating Circuit

19-1439; Rev 1; 5/99

PART

MAX1719EUT

-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 [phone].
For small orders, phone [phone].

SOT

TOP MARK

AACA

MAX1721EUT

-40°C to +85°C 6 SOT23-6 AABT

MAX1720EUT

-40°C to +85°C 6 SOT23-6 AABS

MAX1719/MAX1720/MAX1721

SOT23, Switched-Capacitor
Voltage Inverters with Shutdown

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF

(MAX1719/MAX1721), circuit of Figure 1, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

IN to GND.................................................................-0.3V to +6V

OUT to GND.............................................................-6V to +0.3V

C1+, SHDN, SHDN to GND.........................-0.3V to (V

IN

+ 0.3V)

C1- to GND...............................................(V

OUT

- 0.3V) to +0.3V

OUT Output Current..........................................................100mA

OUT Short Circuit to GND..............................................Indefinite

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 8.7mW/°C above +70°C).................696mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range.............................-65°C to +150°C

Lead Temperature (soldering, 10sec).............................+300°C

I

OUT

= 5mA

MAX1719/MAX1721
RL= 10kΩ

SHDN/ SHDN = GND
or V

IN

V

IN (MIN)

≤ VIN≤ +2.5V

MAX1720
RL= 10kΩ

+2.5V ≤ VIN≤ +5.5V

V

IN (MIN)

≤ VIN≤ +2.5V

+2.5V ≤ VIN≤ +5.5V

I

OUT

= 0, TA= +25°C

SHDN = IN (MAX1719), SHDN = GND
(MAX1720/MAX1721), OUT is internally
forced to GND in shutdown

TA= +25°C

TA= +25°C
SHDN = IN (MAX1719),

SHDN = GND
(MAX1720/MAX1721)

I

OUT

= 10mA

CONDITIONS

80

µs

800

Wake-Up Time from Shutdown

10

nA

-100 0.05 100

IIL, I

IH

SHDN/ SHDN Bias Current

0.2

V

0.6

V

IL

SHDN/ SHDN Input Logic Low

VIN- 0.2

V

2.0

V

IH

SHDN/ SHDN Input Logic High

Ω412RO,

SHDN

OUT to GND
Shutdown Resistance

65

Ω

23 50

R

O

Output Resistance (Note 1)

1.4 5.5

1.5 5.5
V

1.25 5.5

V

IN

Supply Voltage Range

%

99 99.9Voltage Conversion Efficiency

70 125 180

kHz

71217

f

OSC

Oscillator Frequency

0.02

1.5 5.5

µA

50 90

I

CC

Quiescent Supply Current

350 650

µA

0.001 1

I

SHDN

Shutdown Supply Current

UNITSMIN TYP MAXSYMBOLPARAMETER

TA= 0°C to + 85°C

TA= +25°C

TA= 0°C to + 85°C

TA= +25°C

MAX1719/MAX1721

MAX1720

TA= +85°C

TA= +25°C

MAX1719/MAX1721

MAX1720

TA= 0°C to +85°C

TA= +25°C

TA= +85°C

TA= +25°C

MAX1719/MAX1721

MAX1720

MAX1719/MAX1720/MAX1721

SOT23, Switched-Capacitor

Voltage Inverters with Shutdown

_______________________________________________________________________________________

3

-5

-4

-3

-2

-1

0

0202510 155 3035404550

OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX1720/21toc01

OUTPUT CURRENT (mA)

OUTPUT VOLTAGE (V)

VIN = +1.5V

VIN = +2V

VIN = +3.3V

VIN = +5V

0

20
10

40
30

60
50

70

90
80

100

0 1015205 253035 4540 50

MAX1720

EFFICIENCY vs. OUTPUT CURRENT

MAX1720/21toc02

OUTPUT CURRENT (mA)

EFFICIENCY (%)

VIN = +1.5V

VIN = +3.3V

VIN = +2V

VIN = +5V

0

20
10

40
30

60
50

70

90
80

100

0 1015205 253035 4540 50

MAX1719/MAX1721

EFFICIENCY vs. OUTPUT CURRENT

MAX1720/21toc03

OUTPUT CURRENT (mA)

EFFICIENCY (%)

VIN = +1.5V

VIN = +2V

VIN = +3.3V

VIN = +5V

Typical Operating Characteristics

(Circuit of Figure 1, VIN= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = C3, TA= +25°C, unless other­wise noted.)

ELECTRICAL CHARACTERISTICS

(VIN= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF
(MAX1719/MAX1721), circuit of Figure 1, T

A

= -40°C to +85°C, unless otherwise noted.) (Note 2)

V

IN (MIN)

≤ VIN≤ +2.5V

RL= 10kΩ

+2.5V ≤ VIN≤ +5.5V

V

IN (MIN)

≤ VIN≤ +2.5V

+2.5V ≤ VIN≤ +5.5V

I

OUT

= 0

SHDN = IN (MAX1719), SHDN = GND
(MAX1720/MAX1721), OUT is internally
forced to GND in shutdown

MAX1719/MAX1720/MAX1721

I

OUT

= 10mA

CONDITIONS

0.2

V

0.6

V

IL

SHDN/ SHDN Input Logic Low

VIN- 0.2

V

2.0

V

IH

SHDN/ SHDN Input Logic High

Ω12RO,

SHDN

OUT to GND Shutdown
Resistance

65 ΩR

O

Output Resistance (Note 1)

MAX1719/MAX1721

1.6 5.5MAX1719/MAX1721

1.5 5.5MAX1720

%

99Voltage Conversion Efficiency

60 200

kHz

621

f

OSC

Oscillator Frequency

µA

100

I

CC

Quiescent Current

750

UNITSMIN TYP MAXSYMBOLPARAMETER

VV

IN

Supply Voltage Range

MAX1720

Note 1: Capacitor contribution (ESR component plus (1/f

OSC

) · C) is approximately 20% of output impedance.

Note 2: All specifications from -40°C to +85°C are guaranteed by design, not production tested.

Continuous, long-term

25 mA

RMS

I

OUT

Output Current