The vice president of audio chip manufacturer Cirrus Logic Carl Alberty (Carl Alberty) recently accepted an interview to discuss audio chips in smartphones. He said that in recent years, the number of audio amplifier chips (Amplifier) used in smartphones and tablet computers has increased significantly.The American company Cirrus Logic focuses on manufacturing audio-related chips, including DAC, audio amplifier, ADC, codec, clock chip, and digital signal processing chip DSP.
Carl Alberti revealed that Xiaomi Mi Mix Fold is the world’s first smartphone with 4 audio amplifier chips. This phone has four external speakers and each unit is equipped with a chip. Cirrus Logic supplies part of the audio chip to Xiaomi, as well as the Apple iPhone, iPad, Samsung, and Huawei. He said that in recent years, many smartphones have used more and more audio amplifier chips, gradually increasing from one to two. Apple iPhone 12 series mobile phones have three audio amplifier chips.
Xiaomi Mi MIX Fold
Carl emphasized that the external sound quality of smartphones is not only related to audio amplifiers, but the speakers used in mobile phones are also critical. Today’s large-size mobile phone speakers require an independent amplifier chip to provide energy. The biggest challenge in designing this chip is to improve energy conversion efficiency and save battery life.
Carl Alberti revealed that Cirrus Logic released the CS35L45 mono audio amplifier in April 2021, which increased the maximum output power by 30% compared to the previous generation. This chip also has an adaptive power management function, which can protect the battery during high power output. The CS35L45 chip is currently used in the Black Shark 4 Pro gaming phone and ASUS ROG gaming phone 5 produced by Xiaomi.
ROG gaming phone 5
Later this year, Cirrus Logic will also supply CS35L45 and previous generation CS35L41 chips to major smartphone manufacturers.
Carl Alberti also said that the latest thin and light notebooks are thinner than before, which requires thinner speakers to provide good sound quality, similar in shape to the speakers in smartphones. Cirrus Logic will supply audio amplifier chips and touch solutions for notebooks in the future.
Both CS35L41 and CS35L45 chips use class-D amplification mode, integrate DSP, use digital audio signal input, and support a maximum sampling rate of 192 kHz. Among them, the maximum output voltage of CS35L41 is 11V, the maximum output power under 8Ω load is 5.3W, and the idle noise is 9μV. The latest CS35L45 chip has a maximum output voltage of 15V and a maximum power of 6.8W. The product greatly reduces standby energy consumption and idle noise, but the chip volume is also larger.