DataSheet8.cn


PDF ( 数据手册 , 数据表 ) AX2020

零件编号 AX2020
描述 1A Step-down High Brightness LED Driver
制造商 AXElite
LOGO AXElite LOGO 


1 Page

No Preview Available !

AX2020 数据手册, 描述, 功能
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







AX2020 pdf, 数据表
AX2020
Reducing output ripple
Peak to peak ripple current in the LED(s) can be reduced, if required, by shunting a
capacitor CLED across the LED(s) as shown below:
VIN
CIN 4.7uF~100uF
L
0.4 47uH
D
CLED
1uF
VIN
DIM
CSN
AX2020
GND
SW
A value of 1uF will reduce the supply ripple current by a factor three (approx.).
Proportionally lower ripple can be achieved with higher capacitor values. Note that the
capacitor will not affect operating frequency or efficiency, but it will increase start-up delay
and reduce the frequency of dimming, by reducing the rate of rise of LED voltage.
By adding this capacitor the current waveform through the LED(s) changes from a
triangular ramp to a more sinusoidal version without altering the mean current value.
Operation at low supply voltage
The internal regulator disables the drive to the switch until the supply has risen above
the startup threshold (VUVLO). Above this threshold, the device will start to for this reason, the
temperature coefficients of the operating. However, with the supply voltage below the
specified minimum value, the switch duty cycle will be high and the device power dissipation
will be at a maximum. Care should be taken to avoid operating the device under such
conditions in the application, in order to minimize the risk of exceeding the maximum allowed
die temperature. (See next section on thermal considerations). The drive to the switch is
turned off when the supply voltage falls below the under-voltage threshold (VUVLO-1V).
This prevents the switch working with excessive 'on' resistance under conditions where
the duty cycle is high.
Thermal shutdown protection
To ensure the reliability, the AX2020 is built with a thermal shutdown (TSD) protection
function. The TSD protests the IC from over temperature (150°C). When the chip
temperature decreases (115°C), the IC recovers again.
8/11
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.2 Oct.06, 2010














页数 11 页
下载[ AX2020.PDF 数据手册 ]


分享链接

Link :

推荐数据表

零件编号描述制造商
AX20201A Step-down High Brightness LED DriverAXElite
AXElite
AX20210.45A Step-down High Brightness LED DriverAXElite
AXElite

零件编号描述制造商
STK15C88256-Kbit (32 K x 8) PowerStore nvSRAMCypress Semiconductor
Cypress Semiconductor
NJM4556DUAL HIGH CURRENT OPERATIONAL AMPLIFIERNew Japan Radio
New Japan Radio
EL1118-G5 PIN LONG CREEPAGE SOP PHOTOTRANSISTOR PHOTOCOUPLEREverlight
Everlight


DataSheet8.cn    |   2020   |  联系我们   |   搜索  |  Simemap