NSC MAX660M, MAX660MX Datasheet

MAX660
Switched Capacitor Voltage Converter

MAX660 Switched Capacitor Voltage Converter

November 1999

General Description

The MAX660 CMOS charge-pump voltage converter inverts
a positive voltage in the range of 1.5V to 5.5V to the corre­sponding negative voltage. The MAX660 uses two low cost
capacitors to provide 100 mA of output current without the
cost, size, and EMI related to inductor based converters.
With an operating current of only 120 µA and operating effi­ciency greater than 90%at most loads, the MAX660 pro­vides ideal performance for battery powered systems. The
MAX660 may also be used as a positive voltage doubler.

The oscillator frequency can be lowered byadding an exter­nal capacitor to the OSC pin. Also, the OSC pin may be used
to drive the MAX660 with an external clock.Afrequency con­trol (FC) pin selects the oscillator frequency of 10 kHz or 80
kHz.

Typical Application Circuits

Voltage Inverter

DS100898-1

Connection Diagram

Features

n Inverts or doubles input supply voltage
n Narrow SO-8 Package
n 6.5Ω typical output resistance
n 88%typical conversion efficiency at 100 mA
n Selectable oscillator frequency: 10 kHz/80 kHz

Applications

n Laptop computers
n Cellular phones
n Medical instruments
n Operational amplifier power supplies
n Interface power supplies
n Handheld instruments

Positive Voltage Doubler

DS100898-2

8-Lead SO

DS100898-5

Top View

Ordering Information

Order Number Top Mark Package Supplied as

MAX660M Date Code

MAX660M

MAX660MX Date Code

MAX660M

© 1999 National Semiconductor Corporation DS100898 www.national.com

M08A Rail (95 units/rail)

M08A Tape and Reel (2500 units/rail)

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

MAX660

please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage (V+ to GND, or GND to OUT) 6V
LV (OUT − 0.3V) to (GND + 3V)
FC, OSC The least negative of (OUT − 0.3V)

V+ and OUT Continuous Output Current 120 mA

or (V+ − 6V) to (V+ + 0.3V)

Power Dissipation

=

25˚C) (Note 3) 735 mW

(T

A

Max (Note 3) 150˚C

T

J

(Note 3) 170˚C/W

θ

JA

Operating Junction Temp. Range −40˚C to +85˚C
Storage Temperature Range −65˚C to +150˚C
Lead Temperature 300˚C

(Soldering, 10 seconds)

ESD Rating 2 kV

Output Short-Circuit Duration to GND (Note 2) 1 sec.

Electrical Characteristics

Limits in standard typeface are for T
less otherwise specified: V+=5V, FC=Open, C

Symbol Parameter Condition Min Typ Max Units

V+ Supply Voltage R

I

Q

I

L

R

OUT

F

OSC

I

OSC

P

EFF

V

OEFF

Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
beyond its rated operating conditions.

Note 2: OUT may be shorted to GND for one second without damage. However, shorting OUT to V+ may damage the device and should be avoided. Also, for tem­peratures above 85˚C, OUT must not be shorted to GND or V+, or device may be damaged.

Note 3: The maximum allowable power dissipation is calculated by using P
ambient temperature, and θ

Note 4: In the test circuit, capacitors C
age and efficiency.

Note 5: The minimum limit for this parameter is different from the limit of 3.0V for the industry-standard “660” product. For inverter operation with supply voltage be­low 3.5V, connect the LV pin to GND.

Note 6: Specified output resistance includes internal switch resistance and capacitor ESR.

Supply Current No Load FC=Open 0.12 0.5

Output Current TA≤ +85˚C, OUT ≤ −4V 100

Output Resistance (Note 6) I

Oscillator Frequency OSC=Open FC=Open 5 10

OSC Input Current FC=Open

Power Efficiency RL(1k) between V+and OUT 96 98

Voltage Conversion Efficiency No Load 99 99.96

is the junction-to-ambient thermal resistance of the specified package.

JA

=

25˚C, and limits in boldface type apply over the full operating temperature range. Un-

J

=

=

C

150 µF. (Note 4)

1

2

=

1k Inverter, LV=Open

L

(Note 5)

3.5 5.5

Inverter, LV=GND 1.5 5.5 V
Doubler, LV=OUT 2.5 5.5

1 3

>

+85˚C, OUT ≤ −3.8V 100

T

A

=

100 mA T

L

≤ +85˚C 6.5 10

A

>

+85˚C 12

T

A

FC=V+ 40 80

±

2

±

FC=V+

R

(500Ω) between GND and OUT 92 96

L

=

I

100 mA to GND 88

L

=

DMax

and C2are 0.2Ω maximum ESR capacitors. Capacitors with higher ESR will increase output resistance, reduce output volt-

1

(T

JMax−TA

)/θJA, where T

is the maximum junction temperature, TAis the

JMax

16

mALV=Open FC=V+

mA

Ω

kHz

µA

%

%

www.national.com 2

Test Circuit

FIGURE 1. MAX660 Test Circuit

Typical Performance Characteristics

(Circuit of

Figure 1

MAX660

DS100898-4

)

Supply Current vs
Supply Voltage

Output Source Resistance
vs Temperature

DS100898-36

DS100898-39

Supply Current vs
Oscillator Frequency

Efficiency vs Load
Load Current

DS100898-37

DS100898-40

Output Source Resistance
vs Supply Voltage

DS100898-38

Output Voltage Drop
vs Load Current

DS100898-41

www.national.com3

Typical Performance Characteristics (Circuit of

MAX660

Efficiency vs
Oscillator Frequency

Output Voltage vs
Oscillator Frequency

Figure 1

) (Continued)

Oscillator Frequency
vs External Capacitance

Oscillator Frequency
Supply Voltage
(FC=V+)

Oscillator Frequency
vs Temperature
(FC=Open)

DS100898-13

DS100898-16

Oscillator Frequency vs
Supply Voltage
(FC=Open)

DS100898-14

DS100898-17

DS100898-15

Oscillator Frequency vs
Temperature
(FC=V+)

DS100898-18

DS100898-19

www.national.com 4