MM5450 Micrel, MM5450 Datasheet - Page 6

• Manufacturer Part Number: MM5450
• Description: LED Display Driver
• Manufacturer: Micrel

MM5450/5451
Typical Performance Characteristics
Typical Applications
MM5450/5451
RAW DC
> 9 V
Figure 10. Typical Application of Constant Current
110
100
90
80
70
60
50
40
30
20
10
0
0
LM317
I 19 =
5k
240
5
7V
1K
Brightness Control
V
10
NUMBER OF SEGMENTS
V
OUT
V
V
OUT
Figure 7.
= 1V
V
= 1.5V
15
OUT
= 2V
20
–
+
LM324
1.0
0.8
0.6
0.4
0.2
0
5V
25
0
20
1
T = 85°C
A
30
MM5450
20
2N2907
34
SAFE OPERATING
PIN 19
1k
I 19
TEMPERATURE (°C)
40
Figure 9.
AREA
6
60
Figure 11. Brightness Control Varying the Duty Cycle
34 SEGMENTS
V
15 mA/SEGMENT
OUT
CD4046
(VCO)
2.5
2.0
1.5
1.0
0.5
= 1V
0
80
0
5V
4
100
8
MM74HC123
Figure 8.
10 µS
12
I
LED
(mA)
16
T = 85°C
T = 150°C (MAX)
Q 19
A
J
20
24
MM5450
May 2000
20
1
Micrel
28