1

00:00:00,500 --> 00:00:06,766

In this lesson, we will talk about the related circuits of the microphone of the HiSilicon platform

2

00:00:07,233 --> 00:00:10,966

Here we take the Huawei P40 model as an example

3

00:00:11,433 --> 00:00:15,100

Let's take a look at what components are in this circuit

4

00:00:15,566 --> 00:00:18,733

The first component is the main microphone

5

00:00:19,466 --> 00:00:25,333

The main microphone leads to the connector J3601, which is the rear microphone

6

00:00:26,533 --> 00:00:33,066

Another component is the secondary microphone, the position number is MIC3002

7

00:00:34,600 --> 00:00:38,666

The secondary microphone is usually on the top of the phone

8

00:00:40,400 --> 00:00:46,300

As we can see from the frame diagram, both microphones are connected to the main audio

9

00:00:47,166 --> 00:00:51,433

This is the main audio chip of HiSilicon 6405

10

00:00:51,966 --> 00:00:54,766

Another component is the CPU

11

00:00:55,266 --> 00:00:58,233

Let's take a look at how the microphone works

12

00:00:58,533 --> 00:01:01,800

The first is the power supply of the microphone

13

00:01:02,800 --> 00:01:08,966

The power supply of the microphone has a special code in the circuit, MICBIAS_2.6V

14

00:01:11,466 --> 00:01:15,966

The microphone has two lines, A_MIC1P, A_MIC1N

15

00:01:16,466 --> 00:01:19,800

They transmit analog electrical signals

16

00:01:20,700 --> 00:01:25,433

When we speak into this microphone, it converts the sound into an electrical signal

17

00:01:25,433 --> 00:01:27,666

and sends it to the main audio

18

00:01:30,466 --> 00:01:35,400

The main audio performs a series of processing on the analog electrical signal,

19

00:01:35,900 --> 00:01:41,566

such as analog-to-digital conversion, which converts the analog signal into a digital signal,

20

00:01:41,833 --> 00:01:44,700

stores it, or sends it to other circuits

21

00:01:45,833 --> 00:01:49,700

This is a general working principle of the microphone

22

00:01:50,633 --> 00:01:56,066

Its circuit is relatively simple, one power supply, and two signal channels

23

00:01:57,333 --> 00:02:01,500

MIC P is called positive, and MIC N is called negative

24

00:02:02,033 --> 00:02:07,666

The circuit of the secondary microphone also includes a power supply and two signal

25

00:02:08,633 --> 00:02:11,866

After the main audio processes the microphone signal,

26

00:02:11,866 --> 00:02:16,733

it is sent to the processor through the SLIMBUS_CLK bus or SLIMBUS_DATA bus,

27

00:02:16,733 --> 00:02:19,733

and the processor sends it to other circuits

28

00:02:21,500 --> 00:02:27,933

The microphone circuit of Hisilicon P40 is relatively simple, only these three lines

29

00:02:28,266 --> 00:02:34,033

Internally, the main audio is mainly responsible for the signal of the microphone

30

00:02:35,366 --> 00:02:39,266

After the main audio processing, it is given to the processor,

31

00:02:39,266 --> 00:02:43,900

and the processor transmits sound data through the clock bus and data bus

32

00:02:44,866 --> 00:02:49,500

This is the relevant circuit of the microphone of Huawei HiSilicon

33

00:02:49,800 --> 00:02:51,700

That's all for this lesson