Manual

MAX866/MAX867
3.3V/5V or Adjustable-Output,
Single-Cell DC-DC Converters
6 _______________________________________________________________________________________
______________________________________________________________Pin Description
N-Channel Power-MOSFET Drain88
Low-Battery Output. An open-drain N-channel MOSFET sinks current when the voltage at
LBI drops below 1.25V.
44
Low-Battery Input. When the voltage on LBI drops below 1.25V, LBO sinks current.
If not used, connect to V
IN
.
55
Connect OUT to the regulator output. OUT provides bootstrap power to the IC.66
Power Ground. Must be low impedance; solder directly to ground plane.77
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.
33
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
Shutdown Input. When low, the entire circuit is off and V
OUT
= V
IN
- V
D,
where V
D
is the
forward voltage drop of the external Schottky rectifier.
11
FUNCTION
PIN
LX
LBO
LBI
OUT
GND
REF
FB
3/
–
5
–
–
S
—
H
—
D
—
N
–
NAME
MAX866 MAX867
____________________________Typical Operating Characteristics (continued)
(Circuits of Figure 2, T
A
= +25°C, unless otherwise noted.)
24
-60
QUIESCENT SUPPLY CURRENT 
vs. TEMPERATURE
30
28
26
22
MAX866/67-28
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT (µA)
060
-20-40
20
8040 100
20

I
OUT
V
OUT
= 3.47V
1.250
-60
REFERENCE VOLTAGE 
vs. TEMPERATURE
1.255
MAX866/67-29
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
060
-20-40
20
8040 100
1.245

I
REF
= 0A

-60
OUTPUT CURRENT CAPABILITY 
vs. TEMPERATURE
30
25
20
15
MAX866/67-27
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
060
-20-40
20
8040 100
10

V
IN
= 0.9V
3.3V MODE
V
IN
= 1.2V