Skip to main content
Texas Instruments BQ29729DSET — Discrete Semiconductors

BQ29729DSET Battery Protection IC, 1-Cell Li-Ion/Polymer

MPNBQ29729DSET
End of Life

Texas Instruments BQ29729DSET, Battery Protection IC, 1-Cell, Lithium Ion/Polymer, Fault Protection: Over Current, Over/Under Voltage, Short Circuit, 6-WFDFN, -40°C to 85°C.

$1.25Ref. price · indicative, final on quote
Packaging6-WFDFN
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

BQ29729DSET specifications
ParameterValue
MountingSurface Mount
Operating temperature-40°C ~ 85°C (TA)
PackageTape & Reel (TR); Cut Tape (CT)
FunctionBattery Protection
Case6-WFDFN
Number of cells1
Fault protectionOver Current, Over/Under Voltage, Short Circuit
Battery chemistryLithium Ion/Polymer

Product details

What the protection set covers

The fault detection block handles overcurrent during charge and discharge, overvoltage (over-charge), undervoltage (over-discharge), and short-circuit events. That covers the three standard failure modes a single-cell Li-Ion pack needs: cell over-charge, cell over-discharge, and load-side short. There is no integrated FET stage — this is a controller that drives external N-channel MOSFETs, so you size the pass elements for the continuous discharge current your application demands.

Temperature grade and operating range

That puts it in scope for outdoor telecom battery packs, portable instrumentation, and consumer electronics that might see a hot car interior or cold storage. The 6-WSON package with 1.5 mm x 1.5 mm footprint keeps the BOM area small — useful when the protection circuit has to fit inside the battery housing alongside the cell tabs.

Sourcing posture

Frequently asked questions

Is BQ29729DSET RoHS compliant?

Yes, the BQ29729DSET is ROHS3 compliant, covering the full EU RoHS substance restriction set including the four phthalates added in RoHS3.

Does BQ29729DSET support 2-cell batteries?

No, the BQ29729DSET is a single-cell (1-cell) protection IC. For 2-cell to 4-cell packs, look at a multi-cell monitor like the BQ2084DBT-V143, which uses an SMBus interface and targets 2-to-4 series Li-Ion/Polymer stacks.

What is the BQ29729DSET used for?

It monitors for overcurrent, over/under voltage, and short-circuit faults and drives external N-channel MOSFETs to disconnect the cell when thresholds are exceeded. Typical use is in portable device battery packs, power banks, handheld tools, and medical equipment where a hardware safety watch is required independent of the system firmware.