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Typical operating characteristics, Electrical characteristics (continued) – Rainbow Electronics MAX17067 User Manual

Page 4

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Typical Operating Characteristics

(Circuit of Figure 1, V

IN

= 3.3V, f

OSC

= 640kHz, T

A

= +25°C, unless otherwise noted.)

MAX17067

Low-Noise Step-Up DC-DC Converter

4

_______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V

IN

= SHDN = 3V, FREQ = 3V, T

A

= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

n-CHANNEL SWITCH

Current Limit

I

LIM

V

FB

= 1V, duty cycle = 68% (Note 4)

1.8

3.4

A

On-Resistance R

ON

V

IN

= 3V

275

Current-Sense Transresistance

R

CS

0.19 0.40

V/A

SOFT-START

Reset Switch Resistance

100

Charge Current

V

SS

= 1.2V

2.5

6.5

μA

CONTROL INPUTS

Input Low Voltage

V

IL

SHDN, FREQ, V

IN

= 2.6V to 4.0

V

0.3 x

V

IN

V

Input High Voltage

V

IH

SHDN, FREQ, V

IN

= 2.6V to 4.0V

0.7 x

V

IN

V

Note 1: Limit on IN absolute maximum ratings is for operation without the use of an external resistor for the internal clamp circuit.

See the

IN Supply Clamp Circuit section for IN voltage limits during clamping circuit operation.

Note 2: Limits are 100% production tested at T

A

= +25°C. Maximum and minimum limits over temperature are guaranteed by design

and characterization.

Note 3: See the

IN Supply Clamp Circuit section to properly size the external resistor.

Note 4: Current limit varies with duty-cycle slope compensation. See the

Output-Current Capability section.

MAX17067 toc01

50

1

1000

100

10

EFFICIENCY vs. L0AD CURRENT

(V

IN

= 3.3V, V

OUT

= 9V)

70

90

80

100

60

LOAD CURRENT (mA)

EFFICIENCY (%)

f

OSC

= 1.2MHz

L

= 3.3

μH

f

OSC

= 640kHz

L

= 4.7

μH

-0.5

1

1000

100

10

STEP-UP CONVERTER

LOAD REGULATION

0

1.0

0.5

MAX17067 toc02

LOAD CURRENT (mA)

REGULATION (%)

L

= 3.3

μH

INPUT VOLTAGE (V)

500

2.5

5.5

4.5

3.5

5.0

4.0

3.0

SWITCHING FREQUENCY

vs. INPUT VOLTAGE

800

600

1200

1000

1400

900

700

1300

1100

MAX17067 toc03

SWITCHING FREQUENCY (kHz)

FREQ = IN

FREQ = GND