High-Efficiency, PWM, Step-Down

DC-DC Controllers in 16-Pin QSOP

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7

100

50

0.001

0.1

1

0.01

10

EFFICIENCY vs.

LOAD CURRENT (5V/3A CIRCUIT)

60

LOAD CURRENT (A)

70

80

90

V+ = 28V

V+ = 6V

V+ = 12V

MAX1653

f = 300kHz

____________________________________Typical Operating Characteristics (continued)

100

50

0.001

0.1

1

0.01

10

EFFICIENCY vs.

LOAD CURRENT (3.3V/5A CIRCUIT)

60

LOAD CURRENT (A)

70

80

90

V+ = 6V

V+ = 28V

V+ = 12V

MAX1653

f = 300kHz

0

10

5

20

15

25

30

0

10

15

5

20

25

30

PWM-MODE SUPPLY CURRENT vs.

INPUT VOLTAGE (3.3V/3A CIRCUIT)

INPUT VOLTAGE (V)

MAX1653

SKIP = VL

f = 300kHz

NO LOAD

100

50

0.001

0.1

1

0.01

10

EFFICIENCY vs.

LOAD CURRENT (1.8V/2.5A CIRCUIT)

60

LOAD CURRENT (A)

70

80

90

V+ = 6V

V+ = 24V

V+ = 12V

MAX1655

f = 300kHz

0.01

0

30

20

10

25

15

5

IDLE-MODE SUPPLY CURRENT vs.

INPUT VOLTAGE (3.3V/3A CIRCUIT)

0.1

1

10

INPUT VOLTAGE (V)

MAX1653

SKIP = 0

NO LOAD

0

4

2

6

8

10

0

10

15

5

20

25

30

SHUTDOWN SUPPLY CURRENT

vs. INPUT VOLTAGE

INPUT VOLTAGE (V)

SHDN = 0V

0

10

5

20

15

25

30

0

100

150

50

200

250 300 350

400

REF LOAD-REGULATION ERROR

vs. REF LOAD CURRENT

LOAD CURRENT (µA)

0

300

900

600

1200

1500

0

10

15

5

20

25

30

MAX1652 MAXIMUM SECONDARY OUTPUT

CURRENT vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

+5V OUTPUT > 4.75V,

CIRCUIT OF FIGURE 9

+5V LOAD = 0A

+5V LOAD = 3A

0

10

5

20

15

25

50

45

40

35

30

0

20

30

10

40

50

60

70

80

VL LOAD-REGULATION ERROR

vs. VL LOAD CURRENT

LOAD CURRENT (mA)