【摘要】 介绍了电池供电的高精度仪表中 ,低纹波多组输出的隔离DC/DC变换电路及其微功耗电池保护电路的设计。为解决普通DC/DC变换电路存在的问题 ,利用晶体振荡器取得稳定的开关频率 ,通过开关控制把直流电压转换为驱动隔离变压器的交流方波电压 ,以变换成所需的多组输出 ,并通过合理的整流、滤流、稳压电路的设计得到高性能直流电压 ,以满足精密仪表的电源系统要求。在电荷平衡原理的七位半A/D转换器应用中 ,此电源系统引入的误差可以忽略。更多还原

【Abstract】 The low ripple multi-output isolated power spply system and the micro power dissipation battery protected circuit in the battery powered precision instrument are designed.In order to olve the problem the common DC/DC converter existed,the rystal osillator is used to achieve stable switch frequency,and the DC voltage is converted into square wave AC voltage to drive the isolated transformer,and the needed voltages are transformed.By the reasonable design of commutating,filtering and voltage regulating cirucits,the high performance DC voltages are achieved to meet the power system requirement of the precision instrument.In the application of the charge balance based 7 1/2 A/D converter,the errors introduced by the power system can be neglected.更多还原