BQ24251RGER - 2A I2C Li-Ion Charger IC | Texas Instruments
部品番号: BQ24251RGER ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $3.18 | $3.18 |
| 10 | $2.87 | $28.70 |
| 100 | $2.64 | $264.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.26 | $2,260.00 |
BQ24251RGER 概要
A battery charger IC is a power management device that regulates the charging of rechargeable batteries, ensuring safe and efficient energy transfer. The BQ24251 belongs to the battery charger IC family, which falls under battery management ICs, a subset of power management integrated circuits (PMICs). These devices are essential in portable electronics, where they manage charge current, voltage, and thermal conditions to extend battery life and ensure safety.
Key features include a selectable input current limit of 100 mA, 500 mA, 900 mA, 1.5 A, and 2 A, USB charging compliance, BC1.2-compatible D+/D- detection in host mode, and a separate power path that allows system startup from a deeply discharged or missing battery. The I2C interface enables dynamic control of charge parameters, while standalone mode supports autonomous operation without host intervention.
The BQ24251 uses a switched-mode architecture with a high-efficiency synchronous buck converter, achieving up to 92% efficiency. It integrates power-path management, which prioritizes system load over battery charging, reducing battery cycling and enabling instant-on functionality. The device also includes safety features such as thermal regulation, overvoltage protection, and a watchdog timer.
Typical applications include smartphones, tablets, portable media players, and other USB-powered devices. Its power-path management makes it ideal for applications requiring instant system operation even with a depleted battery, such as GPS units and handheld medical devices.
When designing with the BQ24251, ensure proper PCB layout with adequate ground plane and input/output capacitor placement to minimize noise and optimize thermal performance. The I2C address and charge parameters should be configured according to the system requirements, and the watchdog timer must be serviced in host mode to avoid unintended shutdown.
ドロップイン代替品: BQ24251RGER — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: BQ24251RGER （同一形状・フットプリント） — 相違点: Battery Chemistry, Package.
クイック比較ツール — 並列比較する代替部品を選択:
BQ24250RGER
✅ ドロップイン📋 参考代替品（カタログ未掲載）
BQ24252RGER
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
BQ24296RGER
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
BQ24295RGER
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$1.55 / 個
データシートを見る →BQ24610QRGERQ1
⚡ 同一パッケージ✓ 在庫あり
$2.66 / 個
データシートを見る →BQ24251RGER 仕様
| Battery Chemistry | Lithium Ion (Li-Ion) |
| Charge Current | 2 A (up to 2500 mA configurable) |
| Charge Voltage Range | 3.5 V to 4.44 V |
| Input Current Limit Options | 100 mA, 500 mA, 900 mA, 1.5 A, 2 A |
| Charger Topology | Switched-mode synchronous buck |
| 効率 | Up to 92% |
| インターフェース | I2C / standalone |
| USB Detection | BC1.2 compatible D+/D- detection (host mode) |
| Power-Path Management | Yes |
| パッケージ | 24-VQFN (4x4 mm) exposed pad |
| 実装タイプ | Surface Mount |
| Safety Features | Thermal regulation, overvoltage protection, watchdog timer |
| RoHS ステータス | Compliant |
| Packaging | Tape & Reel (RGE suffix R) |
BQ24251RGER ピン構成
| ピン 1 | BOOT — Bootstrap capacitor for high-side gate driver |
| ピン 2 | SW — Switch node of buck converter |
| ピン 3 | PGND — Power ground |
| ピン 4 | CSIN — Battery current sense input (negative) |
| ピン 5 | CSOUT — Battery current sense output (positive) |
| ピン 6 | BAT — Battery voltage sense / connection |
| ピン 7 | SYS — System power-path output |
| ピン 8 | OTG — On-the-go / accessory control input |
| ピン 9 | ILIM — Input current limit programming |
| ピン 10 | D+ — USB D+ for BC1.2 detection |
| ピン 11 | D- — USB D- for BC1.2 detection |
| ピン 12 | STAT/INT — Status output / host interrupt |
| ピン 13 | SDA — I2C serial data |
| ピン 14 | SCL — I2C serial clock |
| ピン 15 | VREF — Internal reference bypass |
| ピン 16 | VIN — Input supply from adapter/USB |
| ピン 17 | PMID — Input MOSFET drain / power path node |
| ピン 21 | AGND — Analog ground |
| ピン 24 | PGND/Thermal Pad — Exposed thermal pad, ground |
主な用途
BQ24251RGER の用途: 6 件s: Smartphone and Tablet Charging, Handheld Medical Devices, Portable GPS Navigation, Portable Media Players, Industrial Handheld Instruments, Wearable and IoT Battery Systems.
Smartphone and Tablet Charging
The BQ24251RGER fits smartphone and tablet charging designs because its 2A synchronous buck charger and selectable input limits (100 mA to 2 A) match USB port capabilities, while BC1.2 D+/D- detection identifies the source port type automatically. Power-path management lets the device boot instantly even with a depleted battery, and I2C control allows the application processor to tune charge voltage (3.5V to 4.44V) and termination current dynamically.
おすすめ
Handheld Medical Devices
In handheld medical diagnostics, the BQ24251RGER enables instant-on operation after long storage because its separate power path starts the system from a deeply discharged or missing battery. Thermal regulation and overvoltage protection safeguard patient-adjacent electronics, while 92% charge efficiency limits heat inside enclosed plastic housings, protecting battery longevity and ensuring reliable multi-hour clinical use.
おすすめ
Portable GPS Navigation
GPS units demand uninterrupted operation during navigation, and the BQ24251RGER delivers it through power-path management that prioritizes system load over charging. With up to 92% synchronous buck efficiency and 2A charge current, a 3000 mAh cell recharges in roughly 1.5 hours while the receiver stays running, and the watchdog timer plus standalone fallback ensures charging continues safely even if the host firmware stalls.
おすすめ
Portable Media Players
Media players benefit from the BQ24251RGER because charging noise is isolated from audio circuitry: the switched-mode charger runs at high efficiency while the power-path SYS rail supplies the audio codec independently of battery charge state. I2C control lets firmware lower charge current during playback to reduce conducted EMI, and BC1.2 detection ensures proper current draw from PCs versus wall adapters.
おすすめ
Industrial Handheld Instruments
Field instruments such as handheld meters and data loggers rely on the BQ24251RGER for robust single-cell management: the selectable 100 mA to 2 A input limit accommodates weak USB power or higher-current adapters, and overvoltage protection tolerates miswired adapters. Host-mode I2C supervision with a watchdog timer provides a failsafe charging profile, critical for unattended industrial equipment that must recover autonomously after a fault.
おすすめ
Wearable and IoT Battery Systems
For smart sensors and IoT wearables, the BQ24251RGER supports small single-cell packs with precise 3.5V to 4.44V regulation and configurable termination, extending cycle life. OTG-style power capability and power-path operation allow accessories to run while charging, and the compact 4x4 mm VQFN-24 fits space-constrained boards; static host control can be dropped by using standalone mode to minimize firmware complexity.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: BQ24251RGER — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | BQ24250RGER | BQ24252RGER | BQ24610QRGERQ1 |
|---|---|---|---|---|
| Package | 24-VQFN (RGE, 4x4 mm) | 24-VQFN (RGE) - same | 24-VQFN (RGE) - same | 24-VQFN (RGE) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| I2C Interface | Yes | No (standalone) | Yes | Standalone |
| BC1.2 D+/D- Detection | Yes (host mode) | No | Yes | No |
| Power-Path Management | Yes | Yes | Yes | Yes (NVDC-type) |
| Automotive Grade (AEC-Q100) | No | No | No | Yes (Q1) |
主な差別化要因
- I2C host control with BC1.2 detection （vs BQ24250RGER)
- Same-footprint automotive upgrade path （vs BQ24610QRGERQ1)
- Power-path instant-on operation （vs BQ24252RGER)
設計ノート
Place the BOOT capacitor close to BOOT/SW pins and keep the SW node loop (VIN, SW, PGND) as small as possible to reduce EMI. Use a solid ground plane with the exposed thermal pad soldered to multiple via stitching for heat spreading. Input and output capacitors must sit within a few millimeters of VIN and SYS/BAT pins per TI BQ2425x datasheet layout guidelines.
Size the inductor for the 2A switching current with adequate saturation margin; the synchronous buck achieves up to 92% efficiency, but at VIN-VOUT deltas above 10V thermal dissipation rises. Verify thermal regulation behavior - the BQ24251 automatically reduces charge current when the junction nears its limit, which extends charge time at high ambient temperature.
In host (I2C) mode, the watchdog timer must be serviced or charge parameters revert to standalone defaults - a frequent field-failure cause. Also ensure BC1.2 detection on D+/D- is disabled or properly sequenced if the USB data lines are shared with a data switch, and never exceed the adapter overvoltage threshold on VIN.
コンプライアンス情報
RoHS compliance per TI product page. For automotive AEC-Q100 qualified charging, see BQ24610QRGERQ1.
