commit 668d6c13c25b491ff05dc6df6fb0f8c4a00f6662
author jhz701 <84003266+jhz701@users.noreply.github.com> Sun Oct 24 02:50:37 2021 -0400
committer GitHub <noreply@github.com> Sun Oct 24 02:50:37 2021 -0400
tree 007a04416bd92c5c0948b9ae0b9f4c89e2c03fc8
parent cac031a3048e30abd17651b0323f4a900abd6be9

Update README.md

README.md

diff --git a/README.md b/README.md
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+++ b/README.md
@@ -1,22 +1,16 @@
-<<<<<<< HEAD
-# class_d_audio_amplifier
-=======
-# Caravel Analog User
+# Class-D Audio Amplifier
+## Overview
 
-[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![CI](https://github.com/efabless/caravel_user_project_analog/actions/workflows/user_project_ci.yml/badge.svg)](https://github.com/efabless/caravel_user_project_analog/actions/workflows/user_project_ci.yml) [![Caravan Build](https://github.com/efabless/caravel_user_project_analog/actions/workflows/caravan_build.yml/badge.svg)](https://github.com/efabless/caravel_user_project_analog/actions/workflows/caravan_build.yml)
+This project is intended to implement a closed-loop class-d audio amplifier with 1.8 V power supply to drive a 8 ohm speaker.
 
----
+## Introduction
 
-| :exclamation: Important Note            |
-|-----------------------------------------|
+An audio amplifier is a circuit used to reproduce input audio signals at sound-producing output elements. Class-D audio amplifier uses a CMOS switch as the output load driver which theoretically consumes no static power and transmits all dynamic power to the load. Thus, the Class-D audio amplifier can achieve high power efficiency.
 
-## Please fill in your project documentation in this README.md file 
+A Class-D audio amplifier is proposed in this project, which is designed with SkyWater Open PDK for the 130nm process. The overall structure of the audio amplifier is shown below. The output is in full-bridge configuration to provide more power to the load and cancel the even harmonics. A negative feedback loop is used to improve the linearity and PSRR. The error signal at the integrator output is compared with a 500 kHz triangular wave to produce the PWM signal, which will be buffered to drive the output switch. A non-overlapping generator is added to prevent the shoot through current. The switching output is filtered with a LC lowpass filter. 
+<img src="https://github.com/jhz701/class_d_audio_amplifier/blob/main/class-d.png" width="150" height="150" alt=""/>
 
-
-:warning: | Use this sample project for analog user projects. 
-:---: | :---
-
----
-
-Refer to [README](docs/source/index.rst) for this sample project documentation. 
->>>>>>> ab6ba9c30b06bc7e68d9478afca6f676c7e4c1ff
+## Schematic
+<img src="https://github.com/jhz701/class_d_audio_amplifier/blob/main/Class_d_sch.png" width="150" height="150" alt=""/>
+## Layout
+<img src="https://github.com/jhz701/class_d_audio_amplifier/blob/main/Class_d_ly.png" width="150" height="150" alt=""/>