摘要
根据便携式系统应用要求,设计了一种高效率、高精度、低噪声电荷泵(Light Emitting Diode,LED)驱动电路.设计采用1倍/1.5倍电荷泵升压方案,驱动4个白光LED.改进的LDO(Low Drop Out)电流控制电路将LED正向电流误差控制在3%以内,同时使系统最高驱动效率达到90.16%.电荷泵电路设计采用8位线性反馈移位寄存器(Linear Feedback Shift Register,LFSR)产生的伪随机序列作为时钟信号,明显实现了开关噪声29.94dB的衰减.设计基于主流CMOS工艺,版图面积为1.51mm×1.14mm,并流片.仿真结果验证了设计的可行性.该驱动电路易于实现便携式系统中不同模块的集成,在实际应用中具有较大的参考价值.
In terms of requirements in portable application, this paper presents the design of high efficiency, high accuracy and low noise LED （Light Emitting Diode） driver circuit. 1X/1.5X charge pump circuit is used to drive 4 LEDs. An improved LDO （Low Drop Out） current regulator circuit is designed to limited current error into 3% and achieves highest drive efficiency of 90.16% at the same time. Charge pump circuit design uses pseudorandom sequence generated by 8 - bit LFSR （Linear Feedback Shift Register）. Switching noise is suppressed for 29.94dB. This design bases on IBM crnrtTsf 5V process, layout area is 1.51mm× 1.14mm. It has been sent for tape out already. Simulation results prove the feasibility of this design. The LED driver designed is easy to be integrated with other modules in portable system and has a great value in practical application.
出处
《微电子学与计算机》
CSCD
北大核心
2010年第2期80-84,共5页
Microelectronics & Computer
基金
教育部科学技术重点资助项目(03151)
