LED driving scheme
High voltage and high brightness linear LED driving scheme
Coreview Technology Introduces High Voltage 350mA, Adjustable High Brightness LED Linear Driver AT8800
A few days ago, Optics Valley, Wuhan, China — Analog and mixed-signal device supplier Core View Technology introduced a high-voltage high-brightness linear LED driver chip AT8800. The AT8800 current regulator can operate from an input voltage range of 6.5V to 40V, providing a total current of up to 350mA to drive one or more columns of high-brightness LEDs. Use an external current-sense resistor in series with the LED to adjust the output current of the AT8800. The enable input enables a wide range of "pulse" brightness control. The waveform shaping circuit reduces EMI. Differential current sense input improves noise rejection. The AT8800 is ideally suited for applications requiring high voltage input and can withstand automotive load dumps up to 40V. On-board adjustment components greatly reduce the number of external components and provide ± 3.5% output current accuracy. The device also provides 5V regulated output and features such as short circuit protection and thermal protection. Through external transistors, the AT8800 can drive LED current up to several amps.
Main features
+ 6.5V to + 40V operating voltage range
Adjustable output current (35mA to 350mA)
Expandable output drive current up to several amps via external transistor
± 3.5% output current accuracy
Built-in adjustment element, low dropout (typical value 0.5V)
Output short-circuit protection
+ 5V regulated output, 4mA source current capability
Thermal shutdown
Differential LED current detection
High-voltage enable pin for brightness control interface
Low shutdown supply current (12µA typical)
204mV low-current detection reference reduces power consumption
The waveform shaping circuit makes the pulse current have smooth edges, thereby reducing the EMI during PWM brightness control
Available in small, thermally enhanced, 5mm x 5mm, 16-pin TQFN and ESOP8 packages
-40 ° C to + 125 ° C operating temperature range
Application
Car interior: map, gated cabin lighting, spotlights
Car exterior: taillights and CHMSL
Traffic warning lights
Navigation and fleet management
General lighting equipment
Nameplate, gas station overhead light, lighthouse
Pin definition and description
|
|
Pin number | Pin number | Description |
OUT | 1,16 | Current regulation output pin, No. 1 and No. 16 PIN pins are connected |
IN | 2,3 | Positive voltage input <, / SPAN> |
N.C. | 4-8,13,14 | Dangling |
CS+ | 9 | Internal differential amplifier inverting input, connect a current detection resistor between CS + and CS- to set the current ILED flowing through the LED |
CS- | 10 | Internal differential amplifier inverting input, connect a current detection resistor between CS + and CS- to set the current ILED flowing through the LED |
V5 | 11 | 5V regulated output, V5 connects 0.1uf capacitor to ground |
GND | 12 | Ground |
EN | 15 | Enable control, active high |
Typical application circuit
Functional Block Diagram
About Wuhan CoreTek Technology Co., Ltd. (AnalogTek),
AnalogTek, headquartered in Optics Valley, Wuhan, China, designs and markets analog and mixed-signal chip products. Its product line includes real-time calendar clock RTC, white and color LED drivers, DC / DC converters, LDO regulators, and power monitoring. Controller, bus expander, LCD controller, satellite receiver LNB control chip, etc. Corechip's chip products are often used in industrial control and consumer electronics markets. Typical applications include LCM modules, LED lighting, electricity meters, MP3, handheld devices, satellite receiving LNBs, navigation systems, set-top boxes, and network routers. For more information about AT8800 chip products, please visit http://www.analogtek.com.cn/product.asp?id=1131; At present the AT8800 can begin to provide samples and accept batch orders.
Contact:
Mr. Xu (Wilson Xu)
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Wuhan Coreview Technology Co., Ltd.
5th Floor, Building A9, Optics Valley Software Park, No. 1 Guanshan 1st Road, East Lake Development Zone, Wuhan
Tel: + 086-027-87611245-8666
Fax: + 086-027-87611255
Mobile: 13307119036
Mail: svcxwf@163.com
Msn: svcxwf@hotmail.com
Web: www.analogtek.com.cn
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