1、Allegro A6210 谷电流模式控制降压稳压方案关键词：电源管理 ,DC/DC 转换器,A6210Allegro 公司的 A6210 是谷电流模式控制降压稳压器, 开关频率高达 2MHz,可以得到非常短的开启时间,非常适合需要高开关频率,高输入电压和低输出 LED 摆幅电压的地方如高亮 LED 和 LED 驱动模块. A6210 输入电压从 9V 到 46V,不需要输出电容,输出电流高达 3A,而待机电流小于 100uA,并具有热关断特性.亮度控制可通过 DIS 引脚的 PWM 来完成.本文介绍了 A6210 的主要特性, 方框图案以及几中应用电路和推荐使用的元件数值和清单.The A6
2、210 is a buck regulator that uses valley current-mode control. This control scheme allows very short switch on-times to be achieved, making it ideal for applications that require high switching frequencies combined with high input voltages and low output LED span voltages. Low system cost is accompl
3、ished through high switching frequencies of up to 2.0 MHz, allowing smaller and lower value inductors and capacitors. In addition, few external components are required through high levels of integration. Optimal drive circuits minimize switching losses.The switching frequency is maintained constant,
4、 as the on-time is modulated by the input voltage. This feed-forward control ensures excellent line correction. The on-time is set by an external resistor pulled-up to the input supply.Internal housekeeping and bootstrap supplies are provided which require the addition of only one small ceramic capa
5、citor. A top-off charge pump ensures correct operation at light loads. Internal diagnostics provide comprehensive protection against input undervoltages and overtemperatures.The device package is a 16-contact, 4 mm 4 mm, 0.75 mm nominal overall height QFN, with exposed pad for enhanced thermal dissi
6、pation. It is lead (Pb) free, with 100% matte tin leadframe plating.A6210 特性和优势 :User-configurable on-time, achieving switching frequencies up to 2.0 MHzBrightness control through PWM of DIS pinMinimal external components requiredNo output capacitor requiredWide input voltage range: 9 to 46 VLow 0.1
7、8 V sense voltage for higher efficiencyOutput Current: up to 3.0 ALow standby current 100 AThermal shutdownSupplied in a thermally-enhanced 4 mm QFN package应用:High brightness LEDsLED driver modules, power supplies and lamps, such as MR16 and MR1图 1.A6210 功能方框图图 2.A6210 应用电路(1)和推荐元件图 3.A6210 应用电路(2)和
8、推荐元件Other Application Circuits Application Circuit 1Channel 1 Current through inductor and LED Assembly, Channel 2 Main switching voltage (LX node)图 4.A6210 应用电路(3)和推荐元件AO-Electronics 傲壹电子 官网： 中文网：Application Circuit 2 Channel 1 Current through inductor and LED Assembly, Channel 2 Main switching voltage (LX node)
