Max1802 digital camera step-down power supply, Typical operating characteristics – Rainbow Electronics MAX1802 User Manual
Page 9
MAX1802
Digital Camera Step-Down
Power Supply
_______________________________________________________________________________________
9
100
0
1
10
100
1000
EFFICIENCY vs. LOAD CURRENT
(CORE CONVERTER)
20
MAX1802 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
IN
= +2.5V
V
IN
= +5V
V
IN
= +3.3V
V
OUT
= +1.8V
Typical Operating Characteristics
(Circuit of Figure 1, V
VDDM
= 6V, V
VDDC
= 3.3V, V
ONM
= 3V, V
ONC
= V
ON1
= V
DCON2
= V
DCON3
= 0, T
A
= +25°C, unless otherwise
noted.)
100
0
1
10
100
1000
10,000
EFFICIENCY vs. LOAD CURRENT
(MAIN CONVERTER)
20
MAX1802 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
OUT
= 3.3V
V
IN
= +5V
V
IN
= +7.2V
V
IN
= +11V
100
0
1
10
100
1000
10,000
EFFICIENCY vs. LOAD CURRENT
(MAIN CONVERTER)
20
MAX1802 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
OUT
= +5V
V
IN
= +7.2V
V
IN
= +11V
100
0
1
10
100
1000
EFFICIENCY vs. LOAD CURRENT
(CORE CONVERTER)
20
MAX1802 toc04
LOAD CURRENT (mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
IN
= +5V
V
IN
= +3.3V
V
OUT
= +2.5V
0
20
60
40
80
100
0.4
0.6
0.7
0.5
0.8
0.9
1.0
1.1
1.2
MAXIMUM DUTY CYCLE vs. V
DCON
_
MAX1802 toc05
V
DCON
_ (V)
MAXIMUM DUTY CYCLE (%)
0
20
60
40
80
100
0
400
200
600
800
1000
DEFAULT MAXIMUM DUTY CYCLE
vs. FREQUENCY
MAX1802 toc06
FREQUENCY (kHz)
DEFAULT MAXIMUM DUTY CYCLE (%)
C
OSC
= 470pF
1000
0
1
10
100
1000
OSCILLATOR FREQUENCY
vs. R
OSC
200
MAX1802 toc07
R
OSC
(k
Ω)
OSCILLATOR FREQUENCY (kHz)
400
600
800
C
OSC
= 470pF
C
OSC
= 220pF
C
OSC
= 100pF
C
OSC
= 47pF
0
2
6
4
8
10
0
4
2
6
8
10
12
MAX1802 toc08
INPUT VOLTAGE (V)
SHUTDOWN CURRENT (
µ
A)
SHUTDOWN CURRENT
vs. INPUT VOLTAGE