Typical operating characteristics – Rainbow Electronics MAX1817 User Manual
Page 5
MAX1817
Compact, High-Efficiency, Dual-Output
Step-Up DC-DC Converter
_______________________________________________________________________________________
5
0.1
10
1
100
1000
MAIN OUTPUT EFFICIENCY
vs. LOAD CURRENT
MAX1817-01
LOAD CURRENT (mA)
EFFICIENCY (%)
95
70
75
85
90
80
A: V
IN
= 3.3V,
V
OUT
= 5V
B: V
IN
= 2.4V,
V
OUT
= 5V
C: V
IN
= 2.4V,
V
OUT
= 3.3V
D: V
IN
= 1.8V,
V
OUT
= 5V
E: V
IN
= 1.8V,
V
OUT
= 3.3V
CIRCUIT OF FIGURE 2
75
25
0.01
0.1
1
10
100
LCD OUTPUT EFFICIENCY
vs. LOAD CURRENT
35
MAX1817-02
LOAD CURRENT (mA)
EFFICIENCY (%)
45
55
65
60
50
40
30
70
A: V
IN
= +2.4V, V
LCD
= 12V
B: V
IN
= +2.4V, V
LCD
= 18V
C: V
IN
= +2.4V, V
LCD
= 24V
D: V
IN
= +1.8V, V
LCD
= 12V
E: V
IN
= +1.8V, V
LCD
= 18V
F: V
IN
= +1.8V, V
LCD
= 24V
V
OUT
= 3.3V,
NO LOAD
A
B
C
D
E
F
0
40
20
80
60
140
120
100
160
1.0
1.2
1.1
1.3
1.4
1.5
1.6
1.7
STARTUP VOLTAGE vs. LOAD CURRENT
MAX1817 toc03
STARTUP VOLTAGE (V)
LOAD CURRENT (mA)
RESISTIVE LOAD
LCD OFF
0
4
2
10
8
6
16
14
12
18
1.0
2.0
1.5
2.5
3.0
3.5
4.0
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (LCD OFF)
MAX1817 toc04
INPUT VOLTAGE (V)
SUPPLY CURRENT (
µ
A)
0
100
50
250
200
150
400
350
300
450
0
2
1
3
4
5
6
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1817-05
INPUT VOLTAGE (V)
SUPPLY CURRENT (
µ
A)
V
OUT
= 3.3V
V
LCD
= 18V, NO LOAD
R1 = 1M
Ω, R2 = 75kΩ
10
µs/div
MAIN CONVERTER
SWITCHING WAVEFORM
MAX1817-06
A: I
LX
, 500mA/div
B: V
OUT
, 50mV/div, AC-COUPLED
C: V
LX
, 5V/div
V
IN
= 2.4V, V
OUT
= 3.3V, I
LOAD,OUT
= 50mA, V
ONLCD
= 0
0
A
B
C
0
4
µs/div
LCD CONVERTER
SWITCHING WAVEFORM
MAX1817-07
A: I
LXLCD
, 500mA/div
B: V
LCD
, 100mV/div, AC-COUPLED
C: V
LXLCD
, 10V/div
V
IN
= 2.4V, V
OUT
= 3.3V, I
LOAD,OUT
= 0,
V
LCD
= 18V, I
LOAD,LCD
= 5mA
0
A
B
C
0
Typical Operating Characteristics
(Circuit of Figure 3, T
A
= +25°C, unless otherwise noted.)