Rainbow Electronics MAX867 - Manual (Page 6)

MAX866/MAX867
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.
If not used, connect to V
IN .
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
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.
1 1
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 (
µ A)
0 60 -20 -40 20 80 40 100
20
I OUT
V OUT = 3.47V
1.250
-60
REFERENCE VOLTAGE
vs. TEMPERATURE
1.255
MAX866/67-29
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
0 60 -20 -40 20 80 40 100
1.245
I REF = 0A
-60
OUTPUT CURRENT CAPABILITY
vs. TEMPERATURE
30
25
20
15
MAX866/67-27
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
0 60 -20 -40 20 80 40 100
10
V IN = 0.9V
3.3V MODE
V IN = 1.2V