3.3V/5V or Adjustable-Output,

Single-Cell DC-DC Converters

6

_______________________________________________________________________________________

______________________________________________________________Pin Description

N-Channel Power-MOSFET Drain

8

8

Low-Battery Output. An open-drain N-channel MOSFET sinks current when the voltage at

LBI drops below 1.25V.

4

4

Low-Battery Input. When the voltage on LBI drops below 1.25V, LBO sinks current.

5

5

Connect OUT to the regulator output. OUT provides bootstrap power to the IC.

6

6

Power Ground. Must be low impedance; solder directly to ground plane.

7

7

1.25V Reference Voltage Output. Bypass with 0.22µF to GND (0.1µF if there is no external

reference load). Maximum load capability is 250µA source, 20µA sink.

3

3

Feedback Input for adjustable-output operation. Connect to an external resistor voltage

divider between OUT and GND.

2

—

Selects the output voltage; connect to GND for 5V output, and to OUT for 3.3V output.

—

2

forward voltage drop of the external Schottky rectifier.

1

1

FUNCTION

PIN

LX

LBO

LBI

OUT

GND

REF

FB

3/

–

5

–

–

S

—

H

—

D

—

N

–

NAME

MAX866

MAX867

____________________________Typical Operating Characteristics (continued)

24

-60

QUIESCENT SUPPLY CURRENT

vs. TEMPERATURE

30

28

26

22

TEMPERATURE (°C)

060

-20

-40

20

80

40

100

20

1.250

-60

REFERENCE VOLTAGE

vs. TEMPERATURE

1.255

TEMPERATURE (°C)

060

-20

-40

20

80

40

100

1.245

-60

OUTPUT CURRENT CAPABILITY

vs. TEMPERATURE

30

25

20

15

TEMPERATURE (°C)

060

-20

-40

20

80

40

100

10

3.3V MODE