Provisional integration guide — researched October 6, 2026. The project's stored datasheet points to LCSC C2927799, identified by LCSC as YONGYUTAI DW01A. The stored download did not return a PDF, and the alternate datasheet did not produce readable, citation-backed evidence after two attempts. Manufacturer product-page facts below are verified against that page; pin assignments, reference-circuit values, and formal absolute-maximum ratings remain explicitly unverified. Do not release a schematic or approve a substitution using the provisional entries alone. Identically named DW01A devices from other manufacturers must not be assumed electrically equivalent.

1. Define B+ / B− as the raw cell terminals and P+ / P− as the protected pack terminals. In the conventional topology, B+ and P+ share the positive conductor.
2. Place two back-to-back N-channel MOSFETs between B− and P−, with their drains joined and sources at the two negative terminals. The B−-side device performs discharge control; the P−-side device performs charge control. Confirm this orientation against the exact reference circuit before implementation.
3. Reference the IC to B− and sense cell positive through an input resistor. Place the bypass capacitor between the IC-side supply node and its cell-negative reference.
4. Sense P− through a separate resistor at the current-sense input. This lets the IC observe the negative-path voltage drop and charger conditions.
5. Connect the load and charger battery terminals to P+ / P−. Any external conductor that bridges B− and P− bypasses the cutoff path; inspect programmer, USB, chassis, and measurement-ground connections.

• Keep the bypass loop small: place C1 at the IC supply/reference pins, with a short return to B−. Keep it away from the main load-current return path.
• Use separate sense branches: pick up B− at the cell-side switch connection and P− at the protected-side connection; avoid shared high-current trace sections that add unintended sensed voltage.
• Size the entire power path: dimension B+/P+ copper, both switch connections, vias, pads, and connectors for normal current, temperature rise, and fault transients. No universal trace width is justified without copper thickness, current, layer geometry, and thermal limits.
• Provide MOSFET thermal copper: use the device manufacturer's pad/thermal guidance. Avoid narrow thermal-relief spokes that compromise the current path; balance solderability against resistance and heat spreading.
• Preserve the cutoff boundary: never flood B− and P− into a common ground zone. Keep gate/sense traces short and away from noisy switching nodes; differential-pair routing is not required for this IC.

1. Treating the protector as a charger, or bypassing its switch path. A cutoff threshold does not regulate charging. Connecting a load, charger, USB return, or test-ground lead directly to B− can defeat low-side protection. Verify the complete assembled product's return paths, not just the protection subcircuit.
2. Buying an unspecified DW01A variant or choosing MOSFETs from threshold voltage alone. Manufacturer identity, protection thresholds, timing, low-cell-voltage behavior, pin 4, and package geometry require exact-part confirmation. MOSFET VGS(th) does not guarantee low-resistance operation at the available battery voltage. Characterize voltage cutoff, overload, short-circuit response, recovery, and temperature with controlled bench tests before product release.

• YONGYUTAI DW01A manufacturer product page — package, published VDD entry, operating temperature, and protection-threshold ranges; no document revision/date supplied on the inspected page.
• YONGYUTAI battery-protection product catalogue — corroborates the manufacturer-specific package and threshold listing.
• LCSC C2927799 product listing — manufacturer identity, distributor attributes, minimum quantity/order multiple, and full-reel quantity; inspected October 6, 2026.
• Required but unread datasheet: Project's LCSC C2927799 datasheet endpoint and YONGYUTAI-labelled PDF hosted by Oneyac. These are retrieval targets, not verified technical evidence. Revision/date, formal ratings, pinout, support values, and package drawing remain unresolved.
• Texas Instruments BQ29700DSET product/ordering page — functional alternative and package. Manufacturer datasheet URL supplied for subsequent exact-part review; not used here to assert numeric threshold equivalence.
• Diodes Incorporated AP9101C product page — functional alternative, package choices, and NRND status. Manufacturer datasheet URL supplied for subsequent exact-ordering-code review; indexed search identifies DS37771 Rev. 8-3, April 2023, but that revision was not independently verified by a successful datasheet read.