AD8240: LED Driver/Monitor
The AD8240 LED driver/monitor, in combination with an external transistor, supplies a constant 12 V to drive LED lamps. This allows cost-effective LED lamp monitoring and short-circuit protection. The output is regulated at 12 V when the supply voltage is between 12.5 V and 27 V.
A CMOS compatible, level-dependent, digital input can be used for PWM control of the LED brightness. VO is turned on when the PWM input is high and turned off when the input is low. The AD8240 is designed to work with a PWM frequency up to 500 Hz, and a typical PWM range from 5% to 95%.
Open LED detection is accomplished by measuring the change in LED lamp current caused by an open LED(s) through the use of an internal high-side current-sense amplifier that amplifies the voltage across an external current shunt. The voltage across the shunt resistor is amplified to a level that can be measured by a microcontroller A/D converter or a comparator. The ability to measure the change in LED lamp current is the key benefit of constant-voltage LED lamp driving.
AD8240 特点
- PWM input for LED Brightness Control
- Open LED Detection
- Latch-off Overcurrent Protection
- Constant Voltage Regulated Output
- Regulated Voltage Range: 12.5V to 27V
- Supply range: 9V to 27 V
- Operating current: 300 uA
- Shutdown current: 10 uA
- Temperature range -40°C to +125°C
- 8-lead MSOP package
AD8240 功能框图
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 |
|---|---|---|---|---|
| AD8240YRM | 量产 | 8 ld MSOP | 8 | 汽车级 |
| AD8240YRM-REEL | 量产 | 8 ld MSOP | 8 | 工业 |
| AD8240YRM-REEL7 | 量产 | 8 ld MSOP | 8 | 工业 |
| AD8240YRMZ | 量产 | 8 ld MSOP | 8 | 汽车级 |
| AD8240YRMZ-R7 | 量产 | 8 ld MSOP | 8 | 工业 |
| AD8240YRMZ-RL | 量产 | 8 ld MSOP | 8 | 工业 |