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TLV431 + LM339 Battery Monitor

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placeMA home_workRemote assignmentContract publicAggregated job · MA

eventPublished on Sep 22, 2026 · verifiedWe confirmed on Sep 22, 2026 that it's still live

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€ 8 – € 30 per project

About the job

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.

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