AAT2400 Datasheet, PDF (23/32 Pages) Skyworks Solutions Inc. – Sixteen-Channel White LED Driver Solution

DATA SHEET
AAT2400/2401
Sixteen-Channel White LED Driver Solution
with Full LED Current and Timing Control
Manufacturer
Diode, Inc.
ON Semi
Part Number
B360A
MBRD360
Rated Foward
Current (A)
3A
3A
Rated Voltage
(V)
60
60
Thermal Resistance,
θ_JA, (°C/W)
100
80
Table 22: Typical Surface Mount Schottky Rectifiers for Various Output Loads
(select T_J < 110°C in Application Circuit).
Case
SMA
DPAK
Selecting the Boost Inductor
The AAT2400 controller utilizes PWM control and the
switching frequency is fixed. To maintain 600kHz switch-
ing frequency and stable operation, a 10μH inductor is
recommended. Manufacturer’s specifications list both
the inductor DC current rating, which is a thermal limita-
tion, and peak inductor current rating, which is deter-
mined by the saturation characteristics. Measurements
at full load and high ambient temperature should be per-
formed to ensure that the inductor does not saturate or
exhibit excessive temperature rise.
The output inductor (L) is selected to avoid saturation at
minimum input voltage and maximum output load condi-
tions. Worst-case peak current occurs at minimum input
voltage (maximum duty cycle) and maximum load. At
high load the switching frequency is somewhat dimin-
ished, resulting in higher I_PEAK. Bench measurements are
recommended to confirm actual I_PEAK and to ensure that
the inductor does not saturate at maximum LED current
and minimum input supply voltage. The RMS current
flowing through the boost inductor is equal to the DC
plus AC ripple components. Under worst case RMS condi-
tions, the current waveform is critically continuous. The
resulting RMS calculation yields worst case inductor loss.
The RMS current value should be compared against the
inductor manufacturer’s temperature rise, or thermal
degrading, guidelines:
I_RMS
=
I_PEAK
3
For a given inductor type, smaller inductor size leads to
an increase in DCR winding resistance and, in most
cases, increased thermal impedance. Winding resistance
degrades boost converter efficiency and increases the
inductor’s operating temperature:
P_LOSS(L) = I^2RMS · DCR
Manufacturer
Cooper
Bussmann
Cooper
Bussmann
Sumida
Sumida
Sumida
Sumida
TDK
TDK
Würth Elektronik
Part Number
DR1040-100-R
DR1050-100-R
CDR12D43RNP-100M
CDR10D48MNNP-100MC
CDRH10D43RNP-100NC
CDRH105RNP-100NC
VLF10045T-100M4R3-PF
RLF12545T-100M5R1-PF
WE-PD Type “LS“ - 100
Inductance
(µH)
10
10
10
10
10
10
10
10
10
Saturated
Rated Current
(A)
4.4
4.58
6.3
5.5
5.2
4.45
4.3
6
4.2
DCR
(mΩ)
26
18
18
32
26.1
26
25
12.4
25
Size (mm)
LxWxH
10.3 x 10.5 x 4.0
10.3 x 10.5 x 5.0
12.4 x 12.4 x 4.5
10.3 x 10.3 x 5.0
10.5 x 10.8 x 4.5
10.3 x 10.5 x 5.0
9.7 x 10.0 x 4.5
12.8 x 12.5 x 4.7
12 x 12 x 4.5
Type
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Shielded Drum Core
Table 23: Typical Suggested Surface Mount Inductors.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
202307A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 24, 2012
23