TLV431 + LM339 Battery Monitor

via Freelancer ·

Budget / Salary€8–30
TypeFreelance project
LocationRemote
Posted1 hour ago
I need a clear, self-contained schematic that uses a TLV431 shunt reference and an LM339 comparator to monitor a single-cell Li-ion battery and flag the full-charge point around 4.20 V. The goal is straightforward battery-level monitoring; once the cell reaches the set threshold the circuit will switch an LED or logic line.

Scope
• Create the diagram from scratch (PDF, PNG, or a file from KiCad/Eagle/Altium—whatever you prefer).
• Choose and calculate all resistor values so the reference network trips at 4.20 V with a small amount of hysteresis to prevent chatter.
• Keep quiescent draw low (≤ 300 µA preferred).
• Include a concise BOM and short calculation notes showing how you arrived at the divider and feedback values.
• Optional but appreciated: SPICE or LTspice plot confirming the threshold.

Flexibility
I’m open to small refinements, such as adding dual-LED status or slightly shifting the trip point if you believe it improves reliability, but the TLV431 + LM339 pairing must stay.

Deliverables
1. Schematic file + high-resolution image/PDF.
2. BOM with part numbers and tolerances.
3. Calculation/justification sheet (brief).
4. (Optional) Simulation results.

Done with esay eda pro you will use and any quick thoughts on setting hysteresis with the TLV431.
electronics electrical engineering pcb layout circuit design
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