519 sky130 Bandgap Reference
519 : sky130 Bandgap Reference
- Author: Guruprasad
- Description: Bandgap reference (~0.9V) with analog VREF output
- GitHub repository
- Open in 3D viewer
- Clock: 0 Hz
Bandgap Reference Overview
This project implements a bandgap reference (BGR) in the Sky130 process to generate a stable voltage of approximately 0.9V, independent of temperature and supply variations.
Architecture
The below figure shows conceptual block diagram of BGR.
The design consists of:
- PTAT current generation
- CTAT voltage component
- Current mirror
- Final stage to convert current to voltage
These components combine to produce a temperature-independent reference voltage.
Key Features
- Technology: Sky130 (1.8V)
- Output: ~0.9V
- Fully custom layout
- Post-layout verified
Tiny Tapeout Integration
- VREF is exposed via
ua[0](analog output)
Notes
- Output is unbuffered
- External loading may affect accuracy
- Intended for characterization and demonstration
Results Summary
- VREF ≈ 0.9V
- Temp coefficient ≈ 20–40 ppm/°C
- Post-layout verified
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | unused | ||
| 1 | unused | ||
| 2 | unused | ||
| 3 | unused | ||
| 4 | unused | ||
| 5 | unused | ||
| 6 | unused | ||
| 7 | unused |
Analog pins
ua | PCB Pin | Internal index | Description |
|---|---|---|---|
| 0 | B5 | 11 | VREF (0.9 Analog output) |