VSD Intern - 10-bit DAC design using eSim and Sky130

Name: VSD Intern - 10-bit DAC design using eSim and Sky130
Rating: 3.9 (109 reviews)

Design 10-bit DAC from scratch using eSim - open source EDA tool for circuit design by FOSSEE IIT Bombay and Sky130 PDKs

Created byKunal Ghosh, Sameer S Durgoji

Last updated 6/2021

English

English [Auto],

What you'll learn

eSim tool usage and installation
DAC IP design - hierarchical approach
Basic circuit design using eSim and Sky130

Course content

5 sections • 14 lectures • 1h 46m total length

Introduction7:50
Introduce how analog signals interface with digital systems, cover adc and dac basics, and illustrate converting a digital word to an analog output with a resistor ladder and switches.
Basic 10-bit DAC design6:10
Understand the basic 10-bit dac design using switches driven by digital input, and outline the schematic to layout workflow with tools such as easy, indispensable, and magic.

eSim installation and basic switch design9:23
Install eSim on Windows, begin a new project, and design a switch schematic by placing MOSFETs, PMOS and NMOS, and wiring components to generate a netlist.
Steps to label and simulate using eSim10:00
Use eSim to label components, assign Sky130 MOSFET models, create a netlist, and run a 40 microsecond simulation to verify the 10-bit DAC switch behavior with digital inputs.

Implement 2-bit DAC using switch9:15
Implement a 2-bit DAC using a switch by designing the switch subcircuit, creating a reusable component in the schematic library, and wiring the digital input for future designs.
2-Bit DAC working10:19
Demonstrates the 2-bit DAC working through eSim and Sky130, detailing schematic opening, subcircuit creation, netlist generation, and pulse-driven digital inputs.
From 2-bit DAC to 10-bit DAC using eSim symbols6:03
Learn a bottom up design of a 10-bit DAC using eSim symbols, building from 2-bit and higher decks with switches, connecting decks, and validating the design through simulation.

Layout and post-layout introduction1:32
Explore the layout and post-layout introduction for a 10-bit DAC design using eSim and Sky130, applying a bottom-up approach to register and deck layouts with simulations.
Layout of resistor9:09
Design the diffusion resistor layout in Sky130 using diffusion resistor layer, define contacts, route interconnects, and run a transient analysis in eSim to verify the 10-bit DAC.
Design of switch layout6:40
Design the switch layout for a 10-bit DAC, detailing diffusion and tunnel considerations, polysilicon gate sizing, contact placement, spacing, and grounding connections in eSim and Sky130.
Labelling, extraction and post-layout simulation7:22
Master labeling, extraction, and post-layout simulation in a 10-bit DAC design using eSim and Sky130. Validate interconnects and digital output through circuit-level simulation.
Design of 2-bit DAC layout10:25
Design a 2-bit digital-to-analog converter layout using eSim and Sky130, connect resistors and switches, verify DRC, and validate the netlist and digital output pulses.
10-bit DAC Layout Design10:21
Design and layout a 10-bit DAC using eSim and Sky130, detailing multi-deck architectures, switch labeling, and simulated outputs across decks.

Requirements

VSD - Circuit design and SPICE simulations
VSD - Custom layout

Description

Most of the signals around us, in the world we live in are not digital in nature, rather they are analog. The digital systems can understand only digital signals, not analog. Hence, it becomes important to interface the digital systems we the external analog world. The analog input signals are to be converted to digital signals using Analog to Digital Converters at the input end of the digital system. After the processing by the system, the digital signals are to be converted back into analog signals using Digital to Analog Converters.

A n-bit Digital to Analog Converter (DAC) takes a n-bit digital word and converts it into a proportional analog voltage with respect to the reference voltage. The potentiometric DAC uses the concept of Voltage Divider. In an N-bit DAC, the analog voltage range, i.e. the Vref (here 3.3 V) is equally divided into 2^N voltage values. This is achieved by a series on 2^N equal resistors and taps are provided across each R. The combination of switches to tap the values is designed using the N-bit digital word as input.

This circuit was designed using eSim

eSim (previously known as Oscad / FreeEDA) is a free/libre and opensource EDA tool for circuit design, simulation, analysis and PCB design. It is an integrated tool built using free/libre and opensource software such as KiCad, Ngspice and GHDL. eSim is released under GPL.

eSim offers similar capabilities and ease of use as any equivalent proprietary software for schematic creation, simulation and PCB design, without having to pay a huge amount of money to procure licenses. Hence it can be an affordable alternative to educational institutions and SMEs. It can serve as an alternative to commercially available/licensed software tools like OrCAD, Xpedition and HSPICE.

Who this course is for:

Beginner VLSI students curious to know about eSim and circuit design
Expert VLSI Physical designers curious to know about custom IP design using real foundry PDKs like Sky130

VSD Intern - 10-bit DAC design using eSim and Sky130

What you'll learn

Explore related topics

Course content

Introduction2 lectures • 14min

eSim Tool installation, circuit design and simualtion2 lectures • 19min

DAC circuit design implementation using eSim3 lectures • 26min

DAC layout using MAGIC6 lectures • 45min

Conclusion1 lecture • 2min

Requirements

Description

Who this course is for: