Rainbow Electronics MAX829 User Manual

General Description

The ultra-small MAX828/MAX829 monolithic, CMOS
charge-pump inverters accept input voltages ranging
from +1.5V to +5.5V. The MAX828 operates at 12kHz,
and the MAX829 operates at 35kHz. Their high efficiency
(greater than 90% over most of the load-current range)
and low operating current (60µA for the MAX828) make
these devices ideal for both battery-powered and board­level voltage-conversion applications.

The MAX828/MAX829 combine low quiescent current
and high efficiency. Oscillator control circuitry and four
power MOSFET switches are included on-chip.
Applications include 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 a similar device with logic-controlled shutdown,
refer to the MAX1719/MAX1720/MAX1721. For applica­tions requiring more power, the MAX860 delivers up to
50mA with a voltage drop of 600mV, in a space-saving
µMAX package.

Applications

Small LCD Panels

Cell Phones

Medical Instruments

Handy-Terminals, PDAs

Battery-Operated Equipment

Features

♦ 5-Pin SOT23-5 Package

♦ 95% Voltage Conversion Efficiency

♦ Inverts Input Supply Voltage

♦ 60µA Quiescent Current (MAX828)

♦ +1.5V to +5.5V Input Voltage Range

♦ Requires Only Two Capacitors

♦ 25mA Output Current

MAX828/MAX829

Switched-Capacitor Voltage Inverters

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

NEGATIVE VOLTAGE CONVERTER

C1+

C1-

IN

OUT

GND

INPUT
SUPPLY
VOLTAGE

NEGATIVE
OUTPUT
VOLTAGE

MAX828
MAX829

4

3

52

1

Typical Operating Circuit

19-0495; Rev 3; 9/99

PART

MAX828EUK

-40°C to +85°C

TEMP. RANGE

PIN-

PACKAGE

5 SOT23-5

Ordering Information

MAX829EUK

-40°C to +85°C 5 SOT23-5

SOT

TOP MARK

AABI

AABJ

For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

TOP VIEW

OUT

IN

C1-

1

2

3

MAX828
MAX829

SOT23-5

C1+

5

GND

4

MAX828/MAX829

Switched-Capacitor Voltage Inverters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +5V, C1 = C2 = 10µF (MAX828), C1 = C2 = 3.3µF (MAX829), TA= 0°C to +85°C, unless otherwise noted. Typical values
are at T

A

= +25°C.)

ELECTRICAL CHARACTERISTICS

(VIN= +5V, C1 = C2 = 10µF (MAX828), C1 = C2 = 3.3µF (MAX829), TA= -40°C to +85°C, unless otherwise noted. Typical values
are at T

A

= +25°C.) (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 above are guaranteed by design.

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

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

MAX828EUK/MAX829EUK ...............................-40°C to +85°C

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

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

MAX829

MAX828

R

LOAD

= ∞

R

LOAD

= 1kΩ, TA= +25°C

MAX829

R

LOAD

= 10kΩ

R

LOAD

= 10kΩ

MAX828

CONDITIONS

µA

150 260

60 90

Supply Current

%95 99.9Voltage Conversion Efficiency

%94Power Efficiency

kHz

24.5 35 45.5

Oscillator Frequency

1.25 1.0
V

1.5

Minimum Supply Voltage

V5.5Maximum Supply Voltage

8.4 12 15.6

UNITSMIN TYP MAXPARAMETER

TA= +25°C

TA= 0°C to + 85°C

I

OUT

= 5mA

TA= 0°C to + 85°C

TA= +25°C

Ω

65

Output Resistance

20 50

MAX829

MAX828

I

OUT

= 5mA

MAX829

R

LOAD

= 10kΩ

MAX828

CONDITIONS

µA

325

115

Supply Current

Ω65Output Resistance

kHz

19 54.3

Oscillator Frequency

V1.5 5.5Supply Voltage Range

620

UNITSMIN TYP MAXPARAMETER

TA= +25°C

TA= +25°C

MAX828/MAX829

Switched-Capacitor Voltage Inverters

_______________________________________________________________________________________ 3

__________________________________________Typical Operating Characteristics

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

OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE

MAX828/829-01

50

45

40

35

30

25

20

OUTPUT RESISTANCE (Ω)

15

10

-40 -20 0 6020 40 80

40

35

30

25

20

15

10

OUTPUT RESISTANCE (Ω)

5

0

1.5 2.5

MAX829

MAX828

3.5 5.54.5

SUPPLY VOLTAGE (V)

MAX829

OUTPUT CURRENT vs. CAPACITANCE

45

40

35

30

25

20

15

OUTPUT CURRENT (mA)

10

5

0

VIN = 4.75V, V- = -4.0V

VIN = 3.15V, V- = -2.5V

VIN = 1.9V, V- = -1.5V

0 5 20 25

CAPACITANCE (µF)

1510 30

500

450

MAX828/829-04

400

350

300

250

200

150

100

OUTPUT VOLTAGE RIPPLE (mVp-p)

50

0

0 5 20 25

OUTPUT RESISTANCE

vs. TEMPERATURE

VIN = 1.5V

VIN = 3.3V

VIN = 5.0V

TEMPERATURE (°C)

MAX828

OUTPUT VOLTAGE RIPPLE

vs. CAPACITANCE

VIN = 4.75V, V
V

IN

V

IN

CAPACITANCE (µF)

OUT

= 3.15V, V

OUT

= 1.9V, V

1510 30

OUT

= -1.5V

= -4.0V
= -2.5V

OUTPUT CURRENT vs. CAPACITANCE

45

40

MAX828/829-02

35

30

25

20

15

OUTPUT CURRENT (mA)

10

VIN = 4.75V, V

VIN = 3.15V, V

VIN = 1.9V, V

5

0

010515 3540

OUTPUT VOLTAGE RIPPLE

vs. CAPACITANCE

450

400

MAX828/829-05

350

300

250

200

150

100

OUTPUT VOLTAGE RIPPLE (mVp-p)

50

0

0 5 20 25

MAX828

= -4.0V

OUT

= -2.5V

OUT

= -1.5V

OUT

20 25 30 45 50

CAPACITANCE (µF)

MAX829

VIN = 4.75V, V
V

= 3.15V, V

IN

V

= 1.9V, V

IN

1510 30

CAPACITANCE (µF)

OUT

OUT

OUT

= -4.0V
= -2.5V

= -1.5V

MAX828/829-03

MAX828/829-06

200

175

150

125

100

75

SUPPLY CURRENT (µA)

50

25

0

1.5 2.5

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX829

MAX828

3.5 5.54.5

SUPPLY VOLTAGE (V)

PUMP FREQUENCY vs. TEMPERATURE

60

55

MAX828/829-07

50

45

40

35

30

25

PUMP FREQUENCY (kHz)

20

15

10

-40 -20 0 60

VIN = 3.3V

MAX828

VIN = 1.5V

VIN = 5.0V

20 40 80

TEMPERATURE (°C)

PUMP FREQUENCY vs. TEMPERATURE

55

MAX828/829-08

50

45

40

PUMP FREQUENCY (kHz)

35

30

-40 -20 0 6020 40 80

MAX829

VIN = 1.5V

VIN = 3.3V

VIN = 5.0V

TEMPERATURE (°C)

MAX828/829-9