BQ24295

The silicon is the same family; the differences are in defaults and OTG behaviour. The BQ24295 is the I2C-controlled version with configurable registers and a 4.208 V default charge voltage. The BQ24296 targets higher-voltage cells (4.35 V/4.4 V class), the BQ24297 has different default register settings and OTG timing, and the M-suffix variants change boost-mode defaults. Always check the register map's reset values in the datasheet for the exact suffix you order, and never assume firmware written for one variant transfers to another without re-checking VREG and OTG defaults.

Heat and charge time. At 5 V input and 3 A into a 3.7 V cell, a linear charger would dissipate about 4 W — impossible in a handheld — while the BQ24295 dissipates under 0.5 W at 90% efficiency. That is why phones and tablets use switch-mode chargers: they can pull 2 A to 3 A from an adapter without cooking the enclosure, and the 1.5 MHz frequency keeps the inductor to 2.2 µH so the whole solution fits in a few square centimetres. The TP4056 remains the right answer below about 500 mA where cost dominates and heat is acceptable.

Yes, that is the point of NVDC power path. SYS is regulated slightly above battery voltage but never below VSYSMIN (programmable, default 3.5 V), so the system has a stable rail from the adapter even with a deeply discharged or absent pack. When adapter current hits the programmed input limit, the device enters dynamic power management: it reduces charge current first, and if the load still cannot be met, the battery FET turns on and the pack supplements the rail with only about 30 mV of drop. Firmware can read the DPM status bit to know when the adapter is undersized.

Wire a 10 kΩ NTC (103AT-2 class) from TS to ground with a divider from REGN through two resistors, and program the cool, cold, warm and hot thresholds in REG06. In the warm zone the device automatically reduces the charge voltage (typically by 140 mV) and in the cool zone it reduces charge current (typically to 50%), which is how you charge a pack safely from 0 °C to 45 °C without firmware intervention. Grounding TS disables the feature — acceptable for prototyping, not for a shipping product. Place the NTC against the cell, not on the PCB near the inductor.

A 2.2 µH inductor rated for ICHG plus half the ripple current — at 3 A charge that means a 3.5 A to 4 A saturation part with low DCR and a 1.2 mm profile. On PMID, at least 20 µF of ceramic close to the pin; 10 µF on BAT and 10 µF on SYS; 0.047 µF from SW to BTST; and 4.7 µF on REGN, which is also the TS bias rail. Keep the PMID-SW-PGND loop under a few square millimetres and solder the thermal pad with vias to the ground plane, otherwise the 32 °C/W junction-to-ambient figure will not be met at 3 A.

No. It is a single-cell device: charge-voltage regulation tops out at 4.4 V and the BAT and SYS pins are rated to 6 V absolute maximum. For 2S packs use the BQ24707, BQ24650 or BQ25302-class devices; for LiFePO4 (3.6 V float) program VREG down to 3.6 V, which is inside the 3.504 V to 4.4 V range, but verify the pre-charge and termination thresholds suit the chemistry and add cell-level protection externally.

QFN remarking is hard to see, so verify electrically and digitally. Read the vendor, device and revision registers over I2C at address 0x6B — a genuine BQ24295 answers correctly, while remarked or clone die either do not respond or return the wrong ID. Then measure: charge-voltage regulation must sit within ±0.5% of the programmed value, switching frequency near 1.5 MHz on the SW node, and ship-mode battery current near 16 µA to 20 µA with the BATFET disabled. Physically, TI QFNs have laser-etched marking and a uniform pad finish; we X-ray and functionally test samples from every reel.

MOQ is 100 pcs loose for prototyping, one small reel of 250 pcs (BQ24295RGET) for pilot builds, or the 3,000-piece production reel (BQ24295RGER) for volume. Shenzhen stock ships in one to two business days; TI authorised channel lead time is eight to sixteen weeks and longer during allocation, so qualify a footprint-compatible fallback early in the programme.