User guide

MAX1800
Digital Camera Step-Up
Power Supply
_______________________________________________________________________________________ 5
Typical Operating Characteristics
(Circuit of Figure 1, V
INPUT
= 2.4V, T
A
= +25°C, unless otherwise noted.)
90
0
1 100010010
MAIN OUTPUT
EFFICIENCY vs. LOAD CURRENT
30
10
70
50
100
40
20
80
60
MAX1800 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
V
OUT
= 2.7V
V
IN
= 2.5V
V
IN
= 2.0V
V
IN
= 1.5V
90
0
1 100010010
MAIN OUTPUT
EFFICIENCY vs. LOAD CURRENT
30
10
70
50
100
40
20
80
60
MAX1800 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
V
OUT
= 3.3V
V
IN
= 3.0V
V
IN
= 2.0V
V
IN
= 2.5V
V
IN
= 1.5V
90
0
1 100010010
30
10
70
50
100
40
20
80
60
MAX1800 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
V
OUT
= 5V
V
IN
= 3.0V
V
IN
= 2.0V
V
IN
= 2.5V
V
IN
= 1.5V
MAIN OUTPUT
EFFICIENCY vs. LOAD CURRENT
1.240
1.245
1.250
1.255
1.260
REFERENCE VOLTAGE vs.
TEMPERATURE
MAX1800 toc05
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
-40 20 40-20 0 60 80
1.247
1.249
1.248
1.251
1.250
1.252
1.253
0 10050 150 200 250
REFERENCE VOLTAGE
vs. REFERENCE CURRENT
MAX1800 toc06
REFERENCE CURRENT (µA)
REFERENCE VOLTAGE (V)
0
400
300
200
100
500
600
0 0.5 1.0 1.5 2.0 2.5
MAX1800 toc04
INPUT VOLTAGE (V)
STARTUP CURRENT (mA)
MINIMUM STARTUP CURRENT
vs. INPUT VOLTAGE