3.3V/5V or Adjustable-Output,

Step-Up DC-DC Converters

2

_______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

Supply Voltage (OUT to GND) ...................................-0.3V, +7V

Switch Voltage (LX to GND) .......................................-0.3V, +7V

S

—

H

—

D

—

N

–

, LBO to GND ....................................................-0.3V, +7V

LBI, REF, 3/

–

5

–

SO (derate 5.88mW/°C above +70°C) .........................471mW

µMAX (derate 4.1mW/°C above +70°C) ......................330mW

CERDIP (derate 8.00mW/°C above +70°C) .................640mW

Operating Temperature Ranges

MAX85_C_ _ ......................................................0°C to +70°C

MAX85_E_ _ ....................................................-40°C to +85°C

MAX85_MJA .................................................-55°C to +125°C

Junction Temperature .....................................................+150°C

Storage Temperature Range ............................-65°C to +160°C

Lead Temperature (soldering, 10sec) ............................+300°C

Note 1: Reverse battery current is measured from the

Typical Operating Circuit’s battery input terminal to GND when the battery is

connected backwards. A reverse current of 750mA will not exceed the SO or CERDIP package dissipation limits but, if left

for an extended time (more than ten minutes), may degrade performance.

LBO = 5V

With falling edge

3/

–

5

–

= 3V, -20µA

No REF load

MAX858/MAX859

–

5

–

(FB = 1.5V, MAX857/MAX859 only)

MAX856/MAX857

S

—

H

—

D

—

N

–

= 0V, 3/

–

5

–

(FB = 1.5V, MAX857/MAX859 only)

2V

CONDITIONS

µA

1

LBO Output Leakage Current

V

0.4

LBO Output Voltage Low

mV

25

LBI Input Hysteresis

V

1.22

1.25

1.28

LBI Input Threshold

%

0.8

2.0

Reference-Voltage Regulation

V

1.23

1.25

1.27

Reference Voltage

mA

125

500

µA

15

Shutdown Quiescent Current

(Note 2)

1

µA

60

No Load Battery Current

4.80

5.0

5.20

3.17

3.3

3.43

4.80

5.0

5.20

µA

25

60

Quiescent Supply Current in

3.3V Mode (Note 2)

V

0.8

Minimum Operating Voltage

4.80

5.0

5.20

3.17

3.3

3.43

V

4.80

5.0

5.20

Output Voltage

V

0.8

1.8

Minimum Start-Up

Supply Voltage

UNITS

MIN

TYP

MAX

PARAMETER

Peak Inductor Current Limit

MAX856, 3/

–

5

–

= 0V, 0mA

MAX856, 3/

–

5

–

= 3V, 0mA

MAX858, 3/

–

5

–

= 0V, 0mA

MAX858, 3/

–

5

–

= 3V, 0mA

MAX85_C

MAX85_E/M