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Typical operating characteristics, Electrical characteristics (continued) – Rainbow Electronics MAX1655 User Manual

Page 3

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MAX1649/MAX1651

5V/3.3V or Adjustable, High-Efficiency,

Low-Dropout, Step-Down DC-DC Controllers

_______________________________________________________________________________________

3

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at T

A

= +25°C.)

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS

CONDITIONS

3V

V+

16V

CS Input Current

±1

µA

C

EXT

= 0.001µF, V+ = 12V

EXT Rise Time

25

ns

C

EXT

= 0.001µF, V+ = 12V

EXT Fall Time

25

ns

Current-Limit Trip Level
(V+ to CS)

mV

V

CS

3V

V+

16V

80

110

140

t

ON

t

ON

+ t

OFF

x 100%

Maximum Duty Cycle

95

96.5

%

80

66

SUPPLY CURRENT vs. TEMPERATURE

68

78

I+ (

µ

A)

76

74

-60

-20

60

140

MAX1649-TOC06

TEMPERATURE (°C)

20

100

-40

0

80

40

120

72

70

V+ = 10V

V+ = 16V

V+ = 4V

4.0

0

SHUTDOWN CURRENT

vs. TEMPERATURE

0.5

3.5

I+ (

µ

A)

3.0

2.5

-60

-20

60

140

MAX1649-TOC05

TEMPERATURE (°C)

20

100

-40

0

80

40

120

2.0

1.5

V+ = 8V

V+ = 16V

V+ = 4V

1.0

V+ = 12V

Switch Maximum On-Time

24

32

40

µs

t

ON

(max)

V+ = 12V

Switch Minimum Off-Time

0.8

1.1

1.8

µs

t

OFF

(min)

-60

-20

60

140

EXT RISE AND FALL TIMES

vs. TEMPERATURE (1nF)

MAX1649/51-01

TEMPERATURE (°C)

t

RISE

& t

FALL

(ns)

20

100

-40

0

80

40

120

60

55

50

45

40

35

30

25

20

15

V+ = 15V, t

FALL

V+ = 15V, t

RISE

V+ = 5V, t

FALL

V+ = 5V, t

RISE

C

EXT

= 1nF

1

10

10k

LOAD CURRENT (mA)

EFFICIENCY (%)

100

90

80

70

60

50

40

100

1k

0.1

MAX1649/51-A1

EFFICIENCY

vs. LOAD CURRENT (V

OUT

= 5V)

V

OUT

= 5V

CIRCUIT OF
FIGURE 1

TOP TO
BOTTOM:

V

IN

= 6V

V

IN

= 8V

V

IN

= 10V

V

IN

= 12V

V

IN

= 15V

__________________________________________Typical Operating Characteristics

(T

A

= +25°C, unless otherwise noted.)

40

-60

-20

60

140

EXT RISE AND FALL TIMES

vs. TEMPERATURE (5nF)

80

MAX1649/51-02

TEMPERATURE (°C)

t

RISE

& t

FALL

(ns)

20

100

-40

0

80

40

120

60

100

140

120

160

200

180

240

220

V+ = 15V, t

FALL

V+ = 15V, t

RISE

V+ = 5V, t

FALL

V+ = 5V, t

RISE

C

EXT

= 5nF

1

10

10k

LOAD CURRENT (mA)

EFFICIENCY (%)

100

90

80

70

60

50

40

100

1k

0.1

MAX1649/51-A2

EFFICIENCY

vs. LOAD CURRENT (V

OUT

= 3.3V)

V

OUT

= 3.3V

CIRCUIT OF
FIGURE 1

TOP TO
BOTTOM:

V

IN

= 4.3V

V

IN

= 5V

V

IN

= 8V

V

IN

= 10V

V

IN

= 12V

V

IN

= 15V