a8434 Allegro MicroSystems, Inc., a8434 Datasheet - Page 5

• Manufacturer Part Number: a8434
• Description: 6-channel High Efficiency Charge Pump White Led Driver
• Manufacturer: Allegro MicroSystems, Inc.

A8434
100.0
95.0
90.0
85.0
80.0
75.0
70.0
65.0
60.0
55.0
1.0
1.2
1.1
0.9
0.8
0.7
0.6
0.5
2.7
2.7
Main
3.1
3.1
Sub
Efficiency versus Supply Voltage
V
IN
falling, V
3.5
3.5
Logic Level
V HI
3.9
3.9
f
= 3.4 V at 20 mA
V
V IN (V)
IN
Main + Sub
(V)
4.3
4.3
Tests performed using application circuit shown in figure 2
Enable Pulses versus Total Current, LED1 through LED6
V LO
C2
C1
T
Performance Characteristics
4.7
A
4.7
= 25°C, V
6-Channel High Efficiency Charge Pump
Dimming on ENM and ENS
Symbol
5.1
5.1
C1
C2
t
IN
= 3.6 V (unless otherwise noted)
5.5
5.5
Parameter Units/Division
t
I
V
LED16
time
ENM
100.0
95.0
90.0
85.0
80.0
75.0
70.0
65.0
60.0
55.0
50.0
30
25
20
15
10
5
50 mA
2.7
50 ms
0.5 V
4
Sub
V
ENM
and V
3.1
6
Efficiency versus Supply Voltage
I
LED1-6
ENS
V
IN
R
SET
falling, V
3.5
R
8
= 6.65 kΩ
SET
Main
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
Main + Sub
White LED Driver
versus LED Current
R
3.9
SET
10
f
R
= 3.1 V at 10 mA
SET
V
= 8.87 kΩ
IN
(kΩ)
(V)
4.3
12
4.7
14
5.1
16
5.5
18
5