CMOS Monolithic Voltage Converter

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3

100

60

0

20

60

100

EFFICIENCY vs. LOAD CURRENT

68

92

LOAD CURRENT (mA)

40

80

84

76

V+ = 5.5V

V+ = 4.5V

V+ = 3.5V

V+ = 1.5V

V+ = 2.5V

400

0

1.5

2.5

4.5

5.5

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

100

300

SUPPLY VOLTAGE (V)

3.5

200

350

250

150

50

2.0

3.0

4.0

5.0

LV = OUT

LV = GND

LV = OPEN

10

0.01

0.1

10

100

SUPPLY CURRENT

vs. OSCILLATOR FREQUENCY

0.1

1

OSCILLATOR FREQUENCY (kHz)

1

-3.0

-5.0

0

20

60

100

OUTPUT VOLTAGE AND EFFICIENCY

vs. LOAD CURRENT, V+ = 5V

-4.6

-3.4

LOAD CURRENT (mA)

40

80

-3.8

-4.2

100

92

84

76

68

60

ICL7660

ICL7660

MAX660

MAX660

EFF.

1.2

0

0

100

OUTPUT VOLTAGE DROP

vs. LOAD CURRENT

0.2

1.0

LOAD CURRENT (mA)

60

0.6

0.4

20

40

80

0.8

10

30

50

70

90

V+ = 4.5V

V+ = 5.5V

V+ = 3.5V

V+ = 2.5V

V+ = 1.5V

__________________________________________Typical Operating Characteristics

-4.0

0.1

10

100

OUTPUT VOLTAGE

vs. OSCILLATOR FREQUENCY

-3.5

-5.0

OSCILLATOR FREQUENCY (kHz)

1

-4.5

-3.0

MAX660

1

2

3

4

8

7

6

5

V+

C2

C1

V+

(+5V )

CAP+

FC

GND

CAP-

OSC

V+

LV

OUT

Figure 1. MAX660 Test Circuit

All curves are generated using the test circuit of Figure 1

unless otherwise noted. The charge-pump frequency is

one-half the oscillator frequency. Test results are also

valid for doubler mode with GND = +5V, LV = OUT, and

OUT = 0V, unless otherwise noted; however, the input

voltage is restricted to +2.5V to +5.5V.