ADP1108 Analog Devices, ADP1108 Datasheet - Page 4

• Manufacturer Part Number: ADP1108
• Description: Micropower DC-DC Converter Adjustable and Fixed 3.3 V/ 5 V/ 12 V
• Manufacturer: Analog Devices

ADP1108
Figure 1. Saturation Voltage vs. I
Current in Step-Up Mode
Figure 4. Maximum Switch Current
vs. R
Figure 7. Oscillator Frequency vs.
Temperature
1100
1000
1.2
0.8
0.6
0.4
0.2
900
800
700
600
500
400
300
200
100
22
21
20
19
18
17
16
15
14
13
1
0
LIM
–40
0.1 0.2
10
V
In Step-Down Mode
IN
V
= 12V WITH L = 250µH @ V
IN
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1
SWITCH CURRENT – Amps
= 24V WITH L = 500µH @ V
–Typical Performance Characteristics
0
TEMPERATURE – C
V
IN
= 2.0V
R
V
100
LIM
25
IN
= 3.0V
–
V
70
OUT
IN
OUT
= 5.0V
= 5V
SWITCH
= 5V
1.2
85
1k
Figure 8. Duty Cycle vs. Temperature
Figure 2. Switch ON Voltage vs.
Switch Current In Step-Down Mode
Figure 5. Supply Current vs. Switch
Current
100
1.6
1.4
1.2
0.8
0.6
0.4
0.2
90
80
70
60
50
40
30
20
10
67
66
65
64
63
62
61
60
59
58
57
1
0
0
0.05
–40
0
100
0.15
200 300 400
SWITCH CURRENT – Amps
SWITCH CURRENT – mA
0.25
0
TEMPERATURE – C
V
CE (SAT)
–4–
0.35
V
25
V
IN
500
0.45
IN
= 2V
= 5V
600 700 800
0.55
70
0.65
0.75
900
85
Figure 3. Maximum Switch Current
vs. R
Figure 6. Quiescent Current vs.
Temperature
1100
1000
34.5
33.5
32.5
31.5
30.5
Figure 9. Switch ON Time vs.
Temperature
900
800
700
600
500
400
300
200
100
120
110
100
35
34
33
32
31
30
90
80
70
60
50
40
–40
LIM
–40
10
2V < V
In Step-Up Mode
IN
0
0
TEMPERATURE – C
< 5V
TEMPERATURE – C
R
LIM
100
25
25
–
70
70
REV. 0
85
1k
85