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AX2020のメーカーはAXEliteです、この部品の機能は「1A Step-down High Brightness LED Driver」です。 |
部品番号 | AX2020 |
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部品説明 | 1A Step-down High Brightness LED Driver | ||
メーカ | AXElite | ||
ロゴ | |||
このページの下部にプレビューとAX2020ダウンロード(pdfファイル)リンクがあります。 Total 11 pages
AX2020
32V,1A Step-down High Brightness
LED Driver with 5000:1 Dimming
GENERAL DESCRIPTION
The AX2020 is a continuous conduction mode inductive step-down converter, designed
for driving single or multiple series connected LED efficiently from a voltage source higher
than the total LED chain voltage. The device operates from an input supply between 8V and
32V and provides an externally adjustable output current of up to 1A. Depending upon the
supply voltage and external components, the AX2020 can provide more than 15 watts of
output power. The AX2020 includes the power switch and a high-side output current sensing
circuit, which uses an external resistor to set the nominal average output current, and a
dedicated DIM input accepts a wide range of pulsed dimming. Applying a voltage of 0.3V or
lower to the DIM pin turns the output off and switches the device into a low current standby
state.
The AX2020 is available in SOT89-5L package.
FEATURES
- Simple low parts count
- Wide input voltage range: 8V to 32V
- Up to 1A output current
- Single pin on/off and brightness control using PWM
- Up to 1MHz switching frequency
- Typical 5% output current accuracy
- High-Side Current Sense
- Hysteretic Control: No Compensation
- Adjustable Constant LED Current
Axelite Confidential Materials, do not copy or distribute without written consent.
1/11
1 Page AX2020
ABSOLUTE MAXIMUM RATINGS (at TA=25°C)
Characteristics
Symbol
Rating
Unit
Supply Voltage
VIN
-0.3 to 40
V
Driver output Voltage
SW
-0.3 to 40
V
Current sense input (Respect to VIN)
CSN +0.3 to (-6.0) V
Logic level dimming input
DIM -0.3 to +6 V
Switch output current
ISW 1.2 A
Power Dissipation
PDMAX 1.5 W
Operation Junction Temperature Range
TJ -40 to 125 °C
Storage Temperature
TSTG -55 to 150 °C
Thermal Resistance from Junction to case
θJC 15 °C/W
Thermal Resistance from Junction to ambient
θJA 50 °C/W
Note: θJA is measured with the PCB copper are (need connect to tap) of approximately 1 in2 (Multi-layer).
ELECTRICAL CHARACTERISTICS
The following specifications apply for VIN = 12V, TA=25°C, unless specified otherwise.
Characteristics
Symbol Conditions Min Typ Max Units
Input voltage
VIN 8 - 32 V
Under voltage lock out
VUVLO VIN rising
- 7-V
UVLO Hysterisis
VUVLO_hys VIN falling
- 1000 - mV
Max. Switching Frequency
FSW
- - 1 MHZ
Current Sense
Mean current sense threshold voltage VCSN VIN–VCSN
120 130 140 mV
Sense threshold hysteresis
VCSN_hys
- ±15 - %
CSN Pin Input Current
ICSN VIN–VCSN = 50mV - 0.5 - μA
DIM Input
DIM input voltage High
VDIM_H
2.0 - - V
DIM input voltage Low
VDIM_L
- - 0.3 V
Max. DIM Frequency
fDIM fOSC = 500kHz
Duty cycle
dimming
range
of
low
frequency
DPWM_LF
fDIM = 100Hz
Brightness control range
- - 50
0.02% - 1
- 5000:1 -
kHZ
3/11
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.2 Oct.06, 2010
3Pages AX2020
Output current adjustment by PWM control
A Pulse Width Modulated (PWM) signal with duty cycle PWM can be applied to the
DIM pin, as shown below, to adjust the output current to a value below the nominal average
value set by resistor RS:
IOUT =
0.13 × D
RS
(0≦D≦100%, 0.3V<Vpulse<2.5V)
RS L
VIN 0.4 47uH
CIN 4.7uF~100uF
D
PWM
VIN
DIM
CSN
AX2020
GND
SW
PWM dimming provides reduced brightness by modulating the LED’s forward current
between 0% and 100%. The LED brightness is controlled by adjusting the relative ratios of
the on time to the off time. A 25% brightness level is achieved by turning the LED on at full
current for 25% of one cycle. To ensure this switching process between on and off state is
invisible by human eyes, the switching frequency must be greater than 100 Hz. Above 100
Hz, the human eyes average the on and off times, seeing only an effective brightness that is
proportional to the LED’s on-time duty cycle. The advantage of PWM dimming is that the
forward current is always constant; therefore the LED color does not vary with brightness as
it does with analog dimming. Pulsing the current provides precise brightness control while
preserving the color purity. The dimming frequency of AX2020 can be as high as 20 kHz.
Shutdown mode
Taking the DIM pin to a voltage below 0.3V will turn off the output and the supply
current will fall to a low standby level of 70μA nominal.
6/11
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.2 Oct.06, 2010
6 Page | |||
ページ | 合計 : 11 ページ | ||
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PDF ダウンロード | [ AX2020 データシート.PDF ] |
データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。 |
部品番号 | 部品説明 | メーカ |
AX2020 | 1A Step-down High Brightness LED Driver | AXElite |
AX2021 | 0.45A Step-down High Brightness LED Driver | AXElite |