參數(shù)資料
型號: AAT3164IRN-T1
廠商: Advanced Analogic Technologies, Inc.
英文描述: High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications
中文描述: 高效率1x/1.5x/2x充電泵為六通道白光LED應(yīng)用
文件頁數(shù): 10/14頁
文件大?。?/td> 397K
代理商: AAT3164IRN-T1
AAT3164
High Efficiency 1X/1.5X/2X Charge Pump for
Six-Channel White LED Applications
10
3164.2006.07.1.0
Applications Information
LED Selection
Although the AAT3164 is specifically designed to
drive white LEDs, the device can also be used to
drive most types of LEDs with forward voltage
specifications ranging from 2.0V to 4.7V. LED
applications may include LCD display backlight-
ing, camera photo-flash applications, color (RGB)
LEDs, infrared (IR) diodes for remotes, and other
loads benefiting from a controlled output current
generated from a varying input voltage. Since the
D1 to D6 input current sinks are matched with
negligible voltage dependence, the LED bright-
ness will be matched regardless of the specific
LED forward voltage (V
F
) levels. In some
instances (e.g., in high luminous output applica-
tions such as photo flash), it may be necessary to
drive high-V
F
type LEDs. The low dropout (~0.1V
@ 20mA I
LED
) current sinks in the AAT3164 make
it capable of driving LEDs with forward voltages
as high as 4.7V from an input supply as low as
3.0V. Outputs can be paralleled to drive high-cur-
rent LEDs without complication.
Determining the Maximum LED Current
Level
The value of R
SET
determines the maximum LED
current level. In the typical application, selecting
R
SET
= 26.1k
Ω
results in 20mA/channel LED cur-
rent. From this reference point, the R
SET
value
required for other current levels can be calculated
as:
A visual representation of the maximum LED cur-
rent per channel versus R
SET
value is shown in
Figure 2.
Figure 2: Maximum LED Current vs. R
SET
.
Brightness Control Using the RSET Pin
Additional methods of brightness control can be
achieved with the RSET pin. For example, using an
additional resistor to connect the RSET pin with a
digital output provides a HI/LO control. Figure 3
illustrates a configuration of the RSET pin utilizing
two resistors.
Figure 3: RSET Configuration Using
Two Resistors.
When the digital output is asserted high, the result-
ing brightness level is LO and the individual LED
currents are:
When the digital output is asserted low, the result-
ing brightness level is HI and the individual LED
currents are:
I
LED(HI)
= 870
0.6
R
1
// R
2
I
LED(LO)
= 870
-
0.6
R
1
// R
2
V
IO
R
2
AAT3164
RSET
R
1
R
2
HI/LO
or
V
DAC
R
SET
(k
Ω
)
I
D
0
5
10
15
20
25
30
35
40
45
10
15
20
25
30
35
40
45
50
55
60
65
70
75
R
SET
= 20I
Ω
LED(MAX)
相關(guān)PDF資料
PDF描述
AAT3166 High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3166IWP-T1 High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3167 High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3167ISN-T1 High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3169 High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AAT3166 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3166IWP-T1 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3167 制造商:AAT 制造商全稱:AAT 功能描述:High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3167_07 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications
AAT3167IFO-T1 制造商:AAT 制造商全稱:AAT 功能描述:High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications