A Bcd Process-based Power Amplifier Chip Circuit Design And Layout To Achieve

The tendency of digitalizing of audio and video and the requirements of power saving and environment protection is calling for digitalized audio amplifiers that are more effective and power saving. To satisfy these requirements, digital audio power amplifiers (DAPA) were developed, which become the mainstream of audio domain for their high efficiency, low distortion, and low cost.The high efficiency and low distortion of digital amplifier are directly related to the switching power amplifier. The switching rate (SR), transient response (TR), active range, phase shift, power conversion efficiency and the load driving ability of this stage would affect the performance of the whole system. So, the design of the switching power amplifier is of great importance. H-bridge switching power amplifiers are popular for their high efficiency and large power output.Based on analysis and experiments of mainstream DAA and DAPS, a 10W H-bridge power amplifier circuit is designed with JAZZ 0.5um BCD technology. Amplifying PWM (Pulse Width Modulation) signal, the chip is compatible with 4Ω, 6Ω, 8Ωspeaker loads. It can work in voltage range of 6V～16V, and provide the maximum RMS (Root Meaning Square) power of 27W (4Ωload and V_POWER=16V) and the maximum efficiency of 81% (8Ωload and V_POWER=15V) with over-current, over-temperature and over-voltage protections. It can also be easily tested for its state output circuit.The contents of this paper are featured as follows.(1) Wide input voltage range realizes wide power output: The designed chip employs two voltage supplies, the low voltage and the high voltage. The lower voltage ( V_DDL =3.3V) is for the logic and protection part of the chip,. And the H-bridge output structure is powered by a 6V～16V voltage (V_POWER), and make the output power range from 2W to 27W.(2) High efficiency output: The designed chip has very high output efficiency, and the maximum efficiency is 81 % (with 8Ωload).(3) Three kinds of protection circuits and convenient testing: The designed chip has over-current protection circuit differs from the ancient ones. The state output circuit can feedback all kinds of states in which the designed chip works, so the chip can be easily tested.