analog-temp

# \# Analog Temperature Sensing Prototype



## Project Overview

This project is an Analog Temperature Sensing Board designed for Battery Management Systems (BMS). It utilizes an NTC Thermistor in a voltage divider topology to convert thermal changes into measurable analog voltage signals.



![3D PCB View](images/pcb_3d.png)



![3D PCB View](images/pcb_3d_2.png)



## Technical Specifications

\- Input Voltage (VCC): 5V DC (typical)

\- Top Resistor (R1): 10kΩ Fixed (0805 SMD)

\- Bottom Resistor (TH1): 10kΩ NTC Thermistor (0805 SMD)

\- Output: Analog Voltage (Vout) via 2.54mm Header



![Schematic Diagram](images/schematic.png)



## Design \& Layout

The PCB was designed using LibrePCB. The layout is optimized for a small form factor while maintaining clear signal paths between the power source and the microcontroller interface.



## Simulation \& Verification

To verify the circuit's accuracy, I performed an Operating Point (.op) analysis using Ngspice. This step ensures the hardware logic matches the mathematical model before manufacturing.



![Ngspice Simulation Results](images/simulation_result.png)



## Mathematical Model

The output voltage is calculated using the Voltage Divider formula:

$$V\_{out} = V\_{in} \\times \\frac{R\_{NTC}}{R\_1 + R\_{NTC}}$$



## Simulation Results (Ngspice)

\- Scenario 1 (Room Temp @ 25°C): $R\_{NTC} = 10k\\Omega \\rightarrow V\_{out} = 2.5V$

\- Scenario 2 (High Temp): $R\_{NTC} = 5k\\Omega \\rightarrow V\_{out} = 1.66V$



## Tools Used

\- LibrePCB: Schematic Capture \& PCB Layout

\- Ngspice: Circuit Simulation \& Verification

\- GitHub: Documentation and Version Control