Tiny 500mA, 4MHz/2MHz Synchronous

Step-Down DC-DC Converters

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3

Typical Operating Characteristics

EFFICIENCY vs. LOAD CURRENT

1.8V OUTPUT

LOAD CURRENT (mA)

0

10

20

30

40

50

60

70

80

90

100

0.1

1

10

100

1000

MAX8640YEXT18

NO-LOAD SUPPLY CURRENT

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

2.9

3.3

3.7

4.1

4.5

4.9

5

10

15

20

25

30

35

MAX8640ZEXT15

MAX8640YEXT18

SWITCHING FREQUENCY

vs. LOAD CURRENT

LOAD CURRENT (mA)

0

100

200

300

400

500

0.1

1

10

MAX8640ZEXT15

MAX8640YEXT18

OUTPUT VOLTAGE vs. LOAD CURRENT

(VOLTAGE POSITIONING)

LOAD CURRENT (mA)

0

100

200

300

400

500

1.30

1.35

1.40

1.45

1.50

1.55

MAX8640ZEXT15

200mA/div

2V/div

20mV/div

(AC-COUPLED)

10

μs/div

LIGHT-LOAD SWITCHING WAVEFORMS

MAX8640Y/Z toc05

200mA/div

2V/div

0V

0mA

20mV/div

(AC-COUPLED)

200ns/div

MEDIUM-LOAD SWITCHING WAVEFORMS

MAX8640Y/Z toc06

200mA/div

2V/div

0V

0mA

20mV/div

(AC-COUPLED)

200ns/div

HEAVY-LOAD SWITCHING WAVEFORMS

MAX8640Y/Z toc07