Instruction Set Simulator （ISS） is a highly abstracted and executable model of micro architecture. It is widely used in the fields of verification and debugging during the development of microprocessors. However, wi...Instruction Set Simulator （ISS） is a highly abstracted and executable model of micro architecture. It is widely used in the fields of verification and debugging during the development of microprocessors. However, with the emergence of Chip Multi-Processors, the single-core ISS cannot meet the needs of microprocessor development. In this paper, we introduce our multi-core chip architecture first, after that a general methodology to expand a single-core ISS to a multi- core ISS （MCISS） is proposed. On this basis, a real-time comparison environment is created for multi-core verification, and the problems of multi-core communication and synchronization are addressed gracefully. With the ＂save and restore＂ mechanism, the verification procedure and the debugging are speeding up greatly.展开更多
A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented.According to the amplitude of the input signals,the charge pump has two level output voltage rails available...A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented.According to the amplitude of the input signals,the charge pump has two level output voltage rails available to save power.It operates both in current mode at high output load and in pulse frequency modulation （PFM） at light load to reduce the power dissipation.Also,dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range.The prototype is implemented in 0.18μm 3.3 V CMOS technology.Experimental results show that the maximum power efficiency of the charge pump is 79.5%@ 0.5x mode and 83.6%@ lx mode.The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control.An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.展开更多
A speaker driver applied to class G/classⅠwith a single phase power supply is presented.Gain expanding and compressing technology are employed in the signal processing circuit to optimize power dissipation.The circui...A speaker driver applied to class G/classⅠwith a single phase power supply is presented.Gain expanding and compressing technology are employed in the signal processing circuit to optimize power dissipation.The circuit is implemented in 0.18μm N-well CMOS.Experimental results show that the speaker driver has a good audio sound quality and power efficiency.Less than 0.006%THD at a low power range and less than 0.4%at a medium power range can be obtained with a 1 kHz sine wave signal.Maximum output power of 360 mW can be gained at a load of 8Ω.The power efficiency is about twice that of a traditional class AB driver at the power range of 80 mW and shows more than 18%improvement at the higher output power range.展开更多
A high efficiency class-1 linear audio power amplifier （PA） with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors＇ voltage drop. A gain compression tec...A high efficiency class-1 linear audio power amplifier （PA） with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors＇ voltage drop. A gain compression technique is adopted to make the amplifier accommodate a single positive supply. Circuit complicity and chip area are reduced because no charge pump is necessary for the negative supply. A common shared mode voltage and a symmetric layout pattern are used to minimize the non-linearity. A peak efficiency of 80% is reached at peak output power. The measured THD＋N before and after the supply switching point are 0.01% and 0.05%, respectively. The maximum output power is 410 mW for an 8 f2 speaker load. Unlike switching amplifiers, the class-I amplifier operates as a linear amplifier and hence has a low EMI. The advantage of a high efficiency and low EMI makes the class-1 amplifier suitable for portable and RF sensitive applications.展开更多
文摘Instruction Set Simulator （ISS） is a highly abstracted and executable model of micro architecture. It is widely used in the fields of verification and debugging during the development of microprocessors. However, with the emergence of Chip Multi-Processors, the single-core ISS cannot meet the needs of microprocessor development. In this paper, we introduce our multi-core chip architecture first, after that a general methodology to expand a single-core ISS to a multi- core ISS （MCISS） is proposed. On this basis, a real-time comparison environment is created for multi-core verification, and the problems of multi-core communication and synchronization are addressed gracefully. With the ＂save and restore＂ mechanism, the verification procedure and the debugging are speeding up greatly.
文摘A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented.According to the amplitude of the input signals,the charge pump has two level output voltage rails available to save power.It operates both in current mode at high output load and in pulse frequency modulation （PFM） at light load to reduce the power dissipation.Also,dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range.The prototype is implemented in 0.18μm 3.3 V CMOS technology.Experimental results show that the maximum power efficiency of the charge pump is 79.5%@ 0.5x mode and 83.6%@ lx mode.The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control.An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.
文摘A speaker driver applied to class G/classⅠwith a single phase power supply is presented.Gain expanding and compressing technology are employed in the signal processing circuit to optimize power dissipation.The circuit is implemented in 0.18μm N-well CMOS.Experimental results show that the speaker driver has a good audio sound quality and power efficiency.Less than 0.006%THD at a low power range and less than 0.4%at a medium power range can be obtained with a 1 kHz sine wave signal.Maximum output power of 360 mW can be gained at a load of 8Ω.The power efficiency is about twice that of a traditional class AB driver at the power range of 80 mW and shows more than 18%improvement at the higher output power range.
基金supported by the Analog Devices and ASIC Laboratory,China
文摘A high efficiency class-1 linear audio power amplifier （PA） with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors＇ voltage drop. A gain compression technique is adopted to make the amplifier accommodate a single positive supply. Circuit complicity and chip area are reduced because no charge pump is necessary for the negative supply. A common shared mode voltage and a symmetric layout pattern are used to minimize the non-linearity. A peak efficiency of 80% is reached at peak output power. The measured THD＋N before and after the supply switching point are 0.01% and 0.05%, respectively. The maximum output power is 410 mW for an 8 f2 speaker load. Unlike switching amplifiers, the class-I amplifier operates as a linear amplifier and hence has a low EMI. The advantage of a high efficiency and low EMI makes the class-1 amplifier suitable for portable and RF sensitive applications.
