A8507 View Datasheet(PDF) - Allegro MicroSystems
Part Name
Description
MFG CO.
'A8507' PDF : 16 Pages View PDF
A8507
LED Backlight Driver for LCD Monitors and Televisions
Characteristic Performance
99
98
97
96
95
94
93
92
91
90
6 parallel strings, 12 serial LEDs each, ILED = 55 mA
89
88
6 parallel strings, 9 serial LEDs each, ILED = 55 mA
87
6 parallel strings, 12 serial LEDs each, ILED = 80 mA
86
6 parallel strings, 9 serial LEDs each, ILED = 80 mA
85
10 12 14 16 18 20 22 24 26 28
VBAT (V)
Figure 2. Efficiency versus Battery Voltage at various LED configurations, RFSET = 105 kΩ
(500 kHz), RISET = 14.3 kΩ (55 mA) or 10 kΩ (80 mA), Q1 = FQB17N08L, L1 = 10 μH
100
VBAT= 21 V
95
90
85
VBAT= 16 V
VBAT= 12 V
VBAT= 8 V
80
75
0 10 20 30 40 50 60 70 80 90 100
PWM Duty Cycle (%)
Figure 3. Efficiency versus PWM Duty Cycle at various VBAT levels,
5 parallel strings with 9 series LEDs each, ILED = 55 mA per channel
1.007
1.006
1.005
1.004
1.003
1.002
1.001
1.000
0.999
10 12 14 16 18 20 22 24 26 28 30
RISET (kΩ)
Figure 4. Normalized Current Gain versus RISET , normalized to 1 for
RISET = 12.4 kΩ
55.5
55.4
55.3
55.2
55.1
55.0
54.9
-40 -20 0
20 40 60 80 100
Temperature (°C)
Figure 5. LED Current versus Ambient Temperature, RISET = 14.3 kΩ
60
50
40
30
VBAT (V)
20
21
16
10
12
8
0
0
20
40
60
80 100 120
PWM Duty Cycle(%)
Figure 6. Average LED Current versus PWM Duty Cycle at various
VBAT levels, 6 parallel strings with 9 series LEDs each, ILED = 55 mA
per channel, fPWM = 200 Hz
Allegro MicroSystems, Inc.
6
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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