AW8155

July 2018 V1.1

www.awinic.com.cn

13

Copyright © 2018 SHANGHAI AWINIC TECHNOLOGY CO., LTD

Gain=21.5dB,NCN level=0.85w. When there are three rising edges, AW8155 start to work and set

Gain=21.5dB,net audio is enable. When there are four rising edges, AW8155 start to work in Class_AB

mode,while gain is to be set 21. 5dB..

As shown in figure 6, when CTRL pull down above 500us, AW8155 will enter shutdown mode.

Mode 1

Mode 2

Mode 3

Mode 4

One-Wire pulse control

When AW8155 work in different mode,PIN CTRL should be low above 500us which make the AW8155 shut

down, Then series pulse make the AW8155 work in right mode.

MODE2

MODE3

1ms

CTRL

One-wire pulse mode switch

RNS (RF TDD Noise Suppression)

GSM radios transmit using time-division multiple access with 217Hz intervals. The result is an RF signal with

strong amplitude modulation at 217Hz and its harmonics that is easily demodulated by audio amplifiers.

In RF applications, improvements to both layout and component selection decrease the AW8155

’s suscepti-

bility to RF noise and prevent RF signals from being demodulated into audible noise. Minimizing the trace

lengths prevents them from functioning as antennas and coupling RF signals into the AW 8155. Additional RF

immunity can also be obtained from relying on the self-resonant frequency of capacitors as it exhibits the

frequency response similar to a notch filter. Depending on the manufacturer, 10pF to 20pF capacitors typically

exhibit self resonance at RF frequencies. These capacitors, when placed at the input pins, can effectively shunt

the RF noise at the inputs of the AW8155. For these capacitors to be effective, they must have a low-imped-

ance, low-inductance path to the ground plane.

Some RF energy will couple onto audio traces regardless of the effort to prevent this phenomenon from oc-

curring, form audible TDD Noise。The AW8155 features a unique RNS technology, which effectively reduces RF

energy, attenuate the RF TDD-noise, an acceptable audible level to the customer.