摘要
基于PWM技术的D类音频功放已广泛应用于各类电子产品中,PWM载波由振荡器产生,振荡器的性能直接影响D类功放的性能。文中主要从提高电路抗噪能力的角度提出一种基于BCD工艺的低噪声频率稳定振荡器的设计,噪声电流仅为0.42nA。该电路能在10～36V和-40～150℃范围内正常工作,振荡频率随电压的变化率小于1%,且具有主-从工作模式的同步功能。通过一个外接电阻调节振荡频率范围为300～500kHz。该电路已成功应用于一种中功率D类音频功放中。
Class D audio amplifiers based on PWM technology are widely used, the PWM carrier is generated from an oscillator, so the performance of class D amplifier is affected by the oscillator. An low-noise, stable-frequency oscillator based on BCD technology is presented, aimed at improving noise performance, noise current is only 0.42 hA. This oscillator is capable of operating at supply voltage of 10 -36 V and temperature of -40 -＋ 150 ℃, in which it can keep stable frequency, the change of frequency from 10 V to 36 V is less than 1%. It also can be setted in master or slave mode to synchronize the class-D devices. The frequency of this oscillator can be adjusted from 300 -500 kHz by an external resistor. This circuit is successfully applied to a middle power class-D audio amplifier.
出处
《电子器件》
CAS
2010年第1期41-44,共4页
Chinese Journal of Electron Devices
基金
合肥工业大学学生创新基金资助(XS09092)
关键词
振荡器
低噪声BCD工艺
采样定理
频率稳定
D类功放
oscillator
low-noise
BCD technology
sampling theorem
stable-frequency
class D amplifier
