Rainbow Electronics MAX681 User Manual

19-0896; Rev 1; 7/96

+5V to ±10V Voltage Converters

________________General Description

The MAX680/MAX681 are monolithic, CMOS, dual
charge-pump voltage converters that provide ±10V out­puts from a +5V input voltage. The MAX680/MAX681 pro­vide both a positive step-up charge pump to develop
+10V from +5V input and an inverting charge pump to
generate the -10V output. Both parts have an on-chip,
8kHz oscillator. The MAX681 has the capacitors internal to
the package, and the MAX680 requires four external
capacitors to produce both positive and negative voltages
from a single supply.

The output source impedances are typically 150Ω, pro­viding useful output currents up to 10mA. The low quies­cent current and high efficiency make this device suitable
for a variety of applications that need both positive and
negative voltages generated from a single supply.

The MAX864/MAX865 are also recommended for new
designs. The MAX864 operates at up to 200kHz and uses
smaller capacitors. The MAX865 comes in the smaller
µMAX package.

________________________Applications

The MAX680/MAX681 can be used wherever a single
positive supply is available and where positive and nega­tive voltages are required. Common applications include
generating ±6V from a 3V battery and generating ±10V
from the standard +5V logic supply (for use with analog
circuitry). Typical applications include:

±6V from 3V Lithium Cell
Hand-Held Instruments
Data-Acquisition Systems
Panel Meters

Battery-Operated
Equipment

Operational Amplifier
Power Supplies

±10V from +5V Logic
Supply

_________________Pin Configurations

TOP VIEW

C1-

C2+

C2-

V+
C1­C1-

C2+

C2­C2-

1
2
3

MAX681

4
5
6

V-

7

DIP

1

2

MAX680

3

4

V-

DIP/SO

8

V+
C1+

7

V

6

CC

GND

5

V

CC

14

V

CC

13

V

CC

12

V

11

CC

V+

10

GND

9

GND

8

____________________________Features

♦ 95% Voltage-Conversion Efficiency
♦ 85% Power-Conversion Efficiency
♦ +2V to +6V Voltage Range
♦ Only Four External Capacitors Required (MAX680)
♦ No Capacitors Required (MAX681)
♦ 500µA Supply Current
♦ Monolithic CMOS Design

_______________Ordering Information

PART

MAX680CPA

MAX680CSA
MAX680C/D 0°C to +70°C
MAX680EPA
MAX680ESA -40°C to +85°C
MAX680MJA -55°C to +125°C 8 CERDIP
MAX681CPD
MAX681EPD -40°C to +85°C

TEMP. RANGE PIN-PACKAGE

0°C to +70°C
0°C to +70°C

8 Plastic DIP
8 Narrow SO
Dice

-40°C to +85°C 8 Plastic DIP
8 Narrow SO

0°C to +70°C 14 Plastic DIP

14 Plastic DIP

_________Typical Operating Circuits

+5V

V

4.7µF

4.7µF

GND

+5V

FOUR PINS REQUIRED
(MAX681 ONLY)

GND

CC

C1+

MAX680

GND

V

CC

MAX681

GND

V+

V-

V+

V-

C1­C1+

C2-

+5V to ±10V CONVERTER

4.7µF
+10V

-10V

4.7µF
GND

+10V

-10V

GND

MAX680/MAX681

________________________________________________________________

Maxim Integrated Products

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

+5V to ±10V Voltage Converters

ABSOLUTE MAXIMUM RATINGS

VCC................................................................................... +6.2V

V+ ...................................................................................... +12V

V- ..........................................................................................-12V

V- Short-Circuit Duration ...........................................Continuous

V+ Current ..........................................................................75mA

∆V/∆T ..........................................................................1V/µs

V

CC

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.

Continuous Power Dissipation (T

8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .....727mW

8-Pin Narrow SO (derate 5.88mW/°C above +70°C) .....471mW

8-Pin CERDIP (derate 8.00mW/°C above +70°C) ..........640mW

14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) ...800mW

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

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

ELECTRICAL CHARACTERISTICS

(VCC= +5V, test circuit Figure 1, TA= +25°C, unless otherwise noted.)

CONDITIONS UNITSPARAMETER

MIN TYP MAX

= +70°C)

A

MAX680/MAX681

Supply Current mA

Positive Charge-Pump
Output Source Resistance

Negative Charge-Pump
Output Source Resistance

Voltage-Conversion
Efficiency

VCC= 3V, TA= +25°C, RL= ∞

VCC= 5V, TA= +25°C, RL= ∞

VCC= 5V, 0°C ≤ TA≤ +70°C, RL= ∞

VCC= 5V, -40°C ≤ TA≤ +85°C, RL= ∞

VCC= 5V, -55°C ≤ TA≤ +125°C, RL= ∞
MIN ≤ TA≤ MAX, RL= 10kΩ

IL+ = 10mA, IL- = 0mA, VCC= 5V,
TA= +25°C

IL+ = 5mA, IL- = 0mA, VCC= 2.8V,
TA= +25°C

IL+ = 10mA,
IL- = 0mA,
VCC= 5V

IL- = 10mA, IL+ = 0mA, V+ = 10V,
TA= +25°C

IL- = 5mA, IL+ = 0mA, V+ = 5.6V,
TA= +25°C

IL- = 10mA,
IL+ = 0mA,
V+ = 10V

RL= 10kΩ
V+, RL= ∞
V-, RL= ∞

0°C ≤ TA≤ +70°C

-40°C ≤ TA≤ +85°C

-55°C ≤ TA≤ +125°C

0°C ≤ TA≤ +70°C

-40°C ≤ TA≤ +85°C

-55°C ≤ TA≤ +125°C

0.5 1

12

2.5

3

3

2.0 1.5 to 6.0 6.0Supply-Voltage Range
150 250

180 300

325
350
400

90 150

110 175

200
200
250

48Oscillator Frequency

95 99
90 97

V

Ω

Ω

kHz

%85Power Efficiency
%

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+5V to ±10V Voltage Converters

__________________________________________Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE

250

C1-C4 = 10µF

200

150

100

OUTPUT RESISTANCE (Ω)

50

0

2.0

3.0

4.0

OUTPUT VOLTAGE vs. OUTPUT CURRENT

(FROM V+ TO V-)

10

9

8

(V)

|

7

VOUT

|

6

5

C1–C4 = 10µF

4

01234 6789

OUTPUT CURRENT (mA)

MAX680, MAX681

510



R

5.0

R

OUT

OUT



10

9

MAX680/681-TOC1

+

-

6.0

MAX680/681-TOC4

V+

V-

(V)

|

VOUT

|

200

150

100

50

OUTPUT SOURCE RESISTANCE (Ω)

8

7

6

5

4

0

0

-50

OUTPUT VOLTAGE

vs. LOAD CURRENT

V- vs. IL+

- = 0

I

L

V+ vs. IL+

- = 0

I

L

V+ vs. IL-

+ = 0

I

L

V- vs. IL-

+ = 0

I

L

5

10

15

OUTPUT SOURCE RESISTANCE

vs. TEMPERATURE

VCC = 5V

R

+

OUT

R

-

OUT

-25 0 25 50 75 100
TEMPERATURE (°C)

MAX680/681-TOC2

SUPPLY CURRENT (mA)

20

MAX680/681-TOC5

100

OUTPUT RIPPLE (mVp-p)

125

200

150

2.0

1.5

1.0

0.5

0

2.0

OUTPUT CURRENT (I

VCC = 5V

50

0

0

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

RL = ∞

3.0

4.0

OUTPUT RIPPLE vs.

+ OR I

L

MAX681

MAX680

C3, C4 = 100µF

5
OUTPUT CURRENT (mA)

V-

V+

C3, C4 = 10µF

10

5.0

MAX680

V+ AND V-

15

6.0

-)

L

V-

V+

20

MAX680/MAX681

MAX680/681-TOC3

MAX681/681-TOC6

_______________________________________________________________________________________

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