Maxim MAX871EUK, MAX870C-D, MAX870EUK-D, MAX871C-D Datasheet

_______________General Description

The ultra-small MAX870/MAX871 monolithic, CMOS
charge-pump inverters accept input voltages ranging
from +1.4V to +5.5V. The MAX870 operates at 125kHz,
and the MAX871 operates at 500kHz. Their high efficien­cy (90%) and low operating current (0.7mA for the
MAX870) 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 MAX870/
MAX871 application is generating a -5V supply from a
+5V logic supply to power analog circuitry. Both parts
come in a 5-pin SOT23-5 package and can deliver 25mA
with a voltage drop of 500mV.

For applications requiring more power, the MAX860
delivers up to 50mA with a voltage drop of 600mV, in a
space-saving µMAX package.

________________________Applications

Local -5V Supply from 5V Logic Supply
Small LCD Panels
Cell Phones
Medical Instruments
Handy-Terminals, PDAs
Battery-Operated Equipment

____________________________Features

♦ 5-Pin SOT23-5 Package
♦ 99% Voltage Conversion Efficiency
♦ Invert Input Supply Voltage
♦ 0.7mA Quiescent Current (MAX870)
♦ +1.4V to +5.5V Input Voltage Range
♦ Require Only Two Capacitors
♦ 25mA Output Current
♦ Shutdown Control

MAX870/MAX871

Switched-Capacitor Voltage Inverters

________________________________________________________________

Maxim Integrated Products

1

TOP VIEW

IN

GND

C1-

C1+

OUT

SOT23-5

1

5

MAX870
MAX871

2

3

4

__________________Pin Configuration

NEGATIVE VOLTAGE CONVERTER

C1+

C1-

IN

OUT

GND

INPUT
SUPPLY
VOLTAGE

NEGATIVE
OUTPUT
VOLTAGE

MAX870
MAX871

4

3

52

1

__________Typical Operating Circuit

19-1240; Rev 0; 6/97

PART

MAX870C/D

MAX870EUK -40°C to +85°C

0°C to +70°C

TEMP. RANGE

PIN-

PACKAGE

Dice*
5 SOT23-5

______________Ordering Information

*

Dice are tested at TA= +25°C.

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]

MAX871C/D

MAX871EUK -40°C to +85°C

0°C to +70°C Dice*

5 SOT23-5

SOT

TOP MARK

—

ABZN

—

ABZO

MAX870/MAX871

Switched-Capacitor Voltage Inverters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +5V, C1 = C2 = 1µF (MAX870), C1 = C2 = 0.33µF (MAX871), TA= 0°C to +85°C, unless otherwise noted. Typical values
are at T

A

= +25°C.)

ELECTRICAL CHARACTERISTICS

(VIN= +5V, C1 = C2 = 1µF (MAX870), C1 = C2 = 0.33µF (MAX871), TA= -40°C to +85°C, unless otherwise noted.) (Note 2)

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.

Note 1: Capacitor contribution is approximately 20% of the output impedance [ESR + 1 / (pump frequency x capacitance)].

Note 2: All -40°C to +85°C specifications are guaranteed by design.

IN to GND..............................................................+6.0V to -0.3V

OUT to GND..........................................................-6.0V to +0.3V

C1+..............................................................(V

IN

+ 0.3V) to -0.3V

C1-............................................................(V

OUT

- 0.3V) to +0.3V

OUT Output Current ...........................................................50mA

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

Continuous Power Dissipation (T

A

= +70°C)

SOT23-5 (derate 7.1mW/°C above +70°C)...................571mW

Operating Temperature Range

MAX870EUK/MAX871EUK ...............................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

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

MAX871

MAX870

R

LOAD

= 500kΩ,

TA=+25°C

R

LOAD

= 10kΩ

R

LOAD

= 10kΩ

TA= +25°C

CONDITIONS

mA

2.7 3.8

0.7 1.0

Supply Current

96 99

%

90

Power Efficiency

kHz

325 500 675

1.4 1.0
V

1.5

Minimum Supply Voltage

V5.5Maximum Supply Voltage

81 125 169

UNITSMIN TYP MAXPARAMETER

TA= +25°C
TA= 0°C to + 85°C

25

MAX871

MAX870

I

OUT

= 5mA

MAX871

R

LOAD

= 10kΩ

MAX870

CONDITIONS

mA

4.4

1.3

Supply Current

Ω65Output Resistance

kHz

225 775

Oscillator Frequency

V1.6Minimum Supply-Voltage Range

56 194

UNITSMIN TYP MAXPARAMETER

TA= +25°C

Oscillator Frequency

C1 = C2 = 0.47µF

I

OUT

=

5mA

C1 = C2 = 1µF

ΩOutput Resistance (Note 1)

20 50

MAX870

TA= +25°C C1 = C2 = 0.33µF 20 50

C1 = C2 = 0.22µF 25MAX871
C1 = C2 = 0.1µF 35

65TA= 0°C to + 85°C

75

MAX870
MAX871
MAX870
MAX871

R

LOAD

= ∞, TA=+25°C

%

98 99.3

Voltage Conversion Efficiency

MAX870
MAX871

R

LOAD

= ∞

%

97

Voltage Conversion Efficiency

95

MAX870
MAX871

R

LOAD

= 10kΩ V5.5Maximum Supply-Voltage Range

MAX870/MAX871

Switched-Capacitor Voltage Inverters

_______________________________________________________________________________________

3

0

0.5

1.0

1.5

2.0

2.5

3.0

1.5 2.52.0 3.0 3.5 4.0 4.5 5.0 5.5

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX870/71-TOC01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

MAX870

MAX871

60

10

1.5 2.5 3.02.0

OUTPUT RESISTANCE

vs. SUPPLY VOLTAGE

50

MAX828/829-02

SUPPLY VOLTAGE (V)

OUTPUT RESISTANCE (Ω)

3.5 4.0 5.54.5 5.0

40

20

30

MAX870

MAX871

0

15
10

5

20

25

30

35

40

45

50

-40 10-15 35 60 85

MAX870

OUTPUT RESISTANCE vs. TEMPERATURE

MAX870/71 ROC3

TEMPERATURE (°C)

OUTPUT RESISTANCE (Ω)

VIN = 1.5V

VIN = 3.3V

VIN = 5.0V

45

0

0 0.5 3.02.5

MAX870

OUTPUT CURRENT vs. CAPACITANCE

35

40

MAX870/871-04

CAPACITANCE (µF)

OUTPUT CURRENT (mA)

1.0 1.5 2.0 3.5

30
25
20

10

5

15

VIN = 3.15V, V

OUT

= -2.5V

VIN = 1.9V, V

OUT

= -1.5V

VIN = 4.75V, V

OUT

= -4.0V

35

0

0 0.5 2.0

MAX871

OUTPUT CURRENT vs. CAPACITANCE

25

30

MAX870/871-07

CAPACITANCE (µF)

OUTPUT CURRENT (mA)

1.0 1.5 2.5

20

15

10

5

VIN = 3.15V, V

OUT

= -2.5V

VIN = 1.9V, V

OUT

= -1.5V

VIN = 4.75V, V

OUT

= -4.0V

450

0

0 0.5 2.0 2.5 3.0 4.03.5 4.5

MAX870

OUTPUT VOLTAGE RIPPLE

vs. CAPACITANCE

50

350

400

MAX870/871-05

CAPACITANCE (µF)

OUTPUT VOLTAGE RIPPLE (mVp-p)

1.51.0 5.0

300
250
200
150
100

VIN = 4.75V, V

OUT

= -4.0V

V

IN

= 3.15V, V

OUT

= -2.5V

V

IN

= 1.9V, V

OUT

= -1.5V

0

20

10

40

30

60

50

70

-40 10-15 35 60 85

MAX871

OUTPUT RESISTANCE vs. TEMPERATURE

MAX870/71-TOC06

TEMPERATURE (°C)

OUTPUT RESISTANCE (Ω)

VIN = 1.5V

VIN = 3.3V

VIN = 5.0V

0

150
100

50

200

250

300

350

400

450

500

0 1.00.5 1.5 2.0 2.5

MAX871

OUTPUT VOLTAGE RIPPLE

vs. CAPACITANCE

MAX870/71 TOC08

CAPACITANCE (µF)

OUTPUT VOLTAGE RIPPLE (mVp-p)

VIN = 4.75V, V

OUT

= -4.0V

V

IN

= 3.15V, V

OUT

= -2.5V

V

IN

= 1.9V, V

OUT

= -1.5V

__________________________________________Typical Operating Characteristics

(Circuit of Figure 1, VIN= +5V, C1 = C2 = C3, TA= +25°C, unless otherwise noted.)

-5.0

-4.0

-4.5

-3.0

-3.5

-2.0

-2.5

-1.5

-0.5

-1.0

0

0 10 15 205 25 30 35 40 45

MAX870

OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX870/871-TOC9

OUTPUT CURRENT (mA)

OUTPUT VOLTAGE (V)

V

IN

= 2.0V

V

IN

= 3.3V

V

IN

= 5.0V