AL8808WT-7 Diodes Inc., AL8808WT-7 Datasheet - Page 13

• Manufacturer Part Number: AL8808WT-7
• Description: LED Lighting Drivers LED MV Int Switch TS Switch TSOT25 T&R 3K
• Manufacturer: Diodes Inc.

Specifications of AL8808WT-7

• Rohs: yes
• Input Voltage: 6 V to 30 V
• Operating Frequency: 1 MHz
• Maximum Supply Current: 450 uA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: TSOT-25
• Minimum Operating Temperature: - 40 C

Applicatio
Inductor Sele
Recommended
data for selecte
required switchi
LED current acc
The inductor sho
The chosen coil
required mean o
Suitable coils for
The inductor val
The following eq
Switch ‘On’ tim
Switch ‘Off’ tim
Where:
AL8808
Document number
MSS1038-333
MSS1038-683
NPIS64D330M
L is the coil
r
R
I
V
ΔI is the coil
V
R
V
t
t
avg
L
ON
OFF
S
IN
LED
SW
D
is the coil
is the cur
is the dio
is the su
is the re
=
is the s
is the t
=
Part
V
V
IN
on Informat
me:
me:
ection
MTRF
ed component va
curacy (due to pro
L
LED
upply voltage (V)
switch resistance
output current.
quations can be u
ode forward volta
ould be mounted
total LED forward
r: DS35648 Rev. 2
l peak-peak rippl
ng frequency. L
r use with the AL
No.
−
−
inductance (H)
rrent sense resis
inductor values
ue should be cho
quired LED curre
should have a s
resistance (Ω)
V
LED
+
V
D
−
+
I
AVG
L
I
Δ
AVG
L
I
Δ
d as close to the d
saturation current
Lower inductor v
age at the require
L8807 are listed i
G
stance (Ω)
d voltage (V)
tion
alues. The induc
used as a guide,
x
x
ent (A)
opagation delays
osen to maintain
I
for the AL8808
e current (A) {Int
- 2
(Ω) {=0.35Ω nom
(
x
R
(µH)
(
33
68
33
L
S
R
+
S
(cont.)
r
+
Figure 4
L
r
+
L
)
R
SW
0.
0.
0.
D
DCR
n operating duty c
W
ed load current (V
ctance used will
(
(V)
s) and increase p
t higher than the
in the table below
ternally set to 0.4
minal}
alues can be us
device as possib
are in the range
0. Inductor Valu
093
213
124
with reference t
)
I
(A)
2.3
1.5
1.1
SAT
e 33µH to 100µH
sed to increase t
ue with Input Volt
ble with low resis
3
5
1
power dissipation
w:
)
4 x I
V)
w
www.diodes.co
T
cycle and switch
o Figure 1 - Ope
peak output cur
depend on a c
AVG
13 of 20
}
Co
stance/stray induc
erating waveform
H. Note that the
combination of In
rrent and a contin
oilCraft www.coi
n (due to switchin
tage and Numbe
m
he switching freq
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'on'/'off' times ov
Manufactu
Figure
ms.
er of LEDs
e AL8808 Web C
nuous current rat
mp.com
e 41. Typical Swi
nput voltage and
ng losses).
ver the supply vo
quency and redu
ctance connectio
rer
lcraft.com
Calculator provid
ons to the SW pi
oltage and load c
d LED chain vo
uce solution size
ting above the
itching Waveform
m
e but may affect
current range.
n.
es performance
ltage to set the
© Diodes Incorporate
AL8808
January 201
ed
3