BQ25798RQMR - 1-4 Cell 5A Buck-Boost Solar Charger IC | TI
部品番号: BQ25798RQMR ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.55 | $2,550.00 |
BQ25798RQMR 概要
A buck-boost battery charger is a switched-mode DC-DC converter that maintains a stable output voltage even when the input voltage sits below, equal to, or above the battery voltage. BQ25798RQMR sits within the battery management IC family in the broader power management IC category. Compared with buck-only chargers, the buck-boost topology handles wide VIN ranges (such as a depleted solar panel or weak USB source) without a separate pre-boost regulator, reducing BOM and PCB area.
Key specifications include 5-A continuous charging current (with parallel charging for higher power), dual-input source selector with MPPT for photovoltaic panels, integrated ADC for input/battery current and voltage monitoring, and high power density through four integrated N-channel MOSFETs. The IC also features an integrated BATFET that supports fast backup mode for UPS-like operation, USB-PD 3.0 PPS compatibility, and I²C programmable parameters including charge voltage, current limits, and switching frequency.
The BQ25798 utilizes a four-switch buck-boost topology with current-mode control to deliver high efficiency across the full VIN/VBAT range. The internal gate drivers and dead-time optimization minimize body-diode conduction, while the integrated charge-management engine implements JEITA temperature profiles and thermal regulation. The 29-pin VQFN-HR package provides a low-thermal-resistance path, enabling 5-A charging in a compact 4x4 mm footprint without external FETs.
Typical applications include solar-powered USB-C power banks, 2S-4S portable power stations, USB-PD PPS charging docks for power tools, e-bike and e-scooter onboard chargers, and battery backup systems for IoT gateways. The MPPT function targets small photovoltaic panels used in outdoor IoT and consumer solar installations.
When designing with this part, provide adequate thermal copper around the exposed pad and follow TI's layout guidelines for high-current buck-boost loops. Use the Battery Management Studio (BQStudio) GUI or host MCU firmware for I²C configuration.
This page synthesizes distributor pricing, drop-in alternatives, application notes, and a comparison table against competing TI and third-party solutions beyond the manufacturer datasheet.
ドロップイン代替品: BQ25798RQMR — 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。
クイック比較ツール — 並列比較する代替部品を選択:
BQ25792RQMR
✅ ドロップイン📋 参考代替品（カタログ未掲載）
BQ25790RQMR
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
BQ25703RQMR
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
BQ25798RQMR 仕様
| 機能 | Buck-Boost Battery Charger with MPPT and Dual-Input Selector |
| Battery Chemistry | Lithium Ion / Lithium Polymer / LiFePO4 |
| Number of Cells Supported | 1 to 4 cells |
| Charge Current (max) | 5 A |
| Operating Input Voltage Range | 3.5 V to 24 V |
| Charge Voltage Range | 1.024 V to 19.2 V (programmable per cell count) |
| トポロジー | 4-switch buck-boost with I²C control |
| インターフェース | I²C (400 kHz / 3.4 MHz selectable) |
| Integrated Power MOSFETs | Yes (4 N-channel) |
| USB PD Support | USB PD 3.0 PPS |
| MPPT | Yes (periodic input voltage sweep) |
| Dual Input Selector | Yes (programmable priority) |
| Backup Mode | Yes (BATFET reverse-mode for UPS) |
| 動作温度範囲 | -40 C to +85 C |
| パッケージ | VQFN-HR (RQM) 4x4 mm, 29 pins |
| 実装タイプ | Surface Mount |
| MSLレベル | 2 |
| RoHS ステータス | Compliant |
BQ25798RQMR ピン構成
| ピン 1 | VAC1 — Input voltage from primary charger adapter |
| ピン 2 | VAC2 — Input voltage from secondary/USB-C adapter |
| ピン 3 | DPPM |
主な用途
BQ25798RQMR の用途: 6 件s: Solar-Powered USB-C Power Bank, Portable Power Station 2S-4S, USB-PD PPS Power Tool Charger, E-Bike and E-Scooter Onboard Charger, Battery Backup System for IoT Gateways, Solar Outdoor Lighting Controller.
Solar-Powered USB-C Power Bank
The BQ25798RQMR is ideal for solar-powered USB-C power banks up to 4S where its integrated MPPT sweeps the photovoltaic panel operating point and locks onto the maximum-power voltage, while the buck-boost topology accepts any combination of solar, USB PD 3.0 PPS, or legacy 5-V adapter. Its 5-A continuous charge current drives 1S to 4S Li-ion packs at high wattage without external FETs, and the dual-input selector arbitrates between solar and USB-C for highest-energy source selection. Backup mode lets the pack act as a UPS for downstream rails during input dropout.
おすすめ
Portable Power Station 2S-4S
For 2S to 4S portable power stations up to ~100 W, the BQ25798RQMR delivers 5-A charging with USB PD 3.0 PPS input negotiation to pull maximum current from a USB-C adapter, including 9-V/12-V/15-V/20-V PPS profiles. Wide-input buck-boost tolerates weak sources (low-battery source adapters) without collapsing. The internal BATFET drives the system load during discharge, while fast backup mode keeps a downstream DC-DC bus alive during input brownouts. Total solution is compact due to the 4x4 mm VQFN-HR footprint.
おすすめ
USB-PD PPS Power Tool Charger
Power tool charging docks based on USB-PD 3.0 PPS can use the BQ25798RQMR as the secondary-side charger because it accepts 5-V to 20-V PPS contracts and delivers up to 5 A into the 1S to 4S pack. The buck-boost converter holds VOUT stable when the pack voltage sags near VIN during high-current charging, eliminating thermal stress. The I²C-controlled JEITA thermal-regulation loop also protects Li-ion cells in hot tool environments. The 29-pin VQFN-HR footprint is small enough for hand-held dock designs.
おすすめ
E-Bike and E-Scooter Onboard Charger
Lightweight e-mobility onboard chargers benefit from the BQ25798RQMR's wide 3.5-24 V VIN range, which accepts solar panels or generic laptop-style adapters that swing from below to above the pack voltage. Its 5-A continuous charge current charges a 36-V / 48-V pack at 180-240 W in only a few hours without active cooling. MPPT firmware handles small photovoltaic rooftop panels for solar-assisted cargo bikes. The 29-pin QFN package plus internal FETs minimize PCB area under the frame.
おすすめ
Battery Backup System for IoT Gateways
IoT gateways in industrial, telecom, or smart-home applications often stack a wall adapter plus a 2S to 4S backup battery. The BQ25798RQMR's BATFET reverse-mode backup keeps the gateway alive during short power interruptions without a separate UPS IC - the charger itself drives the system load from the battery when VAC drops, then seamlessly switches back to wall-input charging. MPPT also allows pairing with solar trickle-chargers in outdoor 4G/5G gateways. Wide temperature range -40 to +85 C supports outdoor enclosures.
おすすめ
Solar Outdoor Lighting Controller
Outdoor solar lighting controllers running 1S to 4S LiFePO4 packs pair well with the BQ25798RQMR because its MPPT firmware is configured at firmware boot to support small PV panels typically found on solar garden light bollards. The buck-boost topology sustains LED driver input across the full state-of-charge curve, reducing flicker as V_BAT varies. BATFET backup mode enables dusk-to-dawn lighting even with no PV energy available. The 4x4 mm VQFN-HR fits compact bollard heads.
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: BQ25798RQMR — 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 | BQ25792RQMR | BQ25790RQMR | BQ25703RQMR |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | VQFN-HR (RQM) 29-pin 4x4 mm | VQFN-HR (RQM) 29-pin 4x4 mm - same | VQFN-HR (RQM) 29-pin 4x4 mm - same | VQFN-HR (RQM) 29-pin 4x4 mm - same |
| Topology | 4-switch buck-boost | 4-switch buck-boost - same | 4-switch buck-boost - same | 4-switch buck-boost - same |
| Cell Range | 1 to 4 cells | 1 to 4 cells | 1 to 4 cells | 1 to 4 cells |
| Maximum Charge Current | 5 A | 5 A | 5 A | 5 A |
| USB PD 3.0 PPS Support | Yes | Yes | Yes | No |
| Integrated MPPT | Yes | No | Yes | No |
主な差別化要因
- Integrated MPPT with dual-input selector （vs BQ25792RQMR)
- Public stock and improved backup mode （vs BQ25792RQMR)
- USB PD 3.0 PPS native support （vs BQ25703RQMR)
設計ノート
Place 1uH buck-boost inductors as close as possible to the SW1/SW2 nodes with the high-side input ceramic caps (typically 2.2uF each) adjacent to PMID. The exposed thermal pad of the VQFN-HR RQM package must be soldered to a copper pour of at least 10x10 mm with thermal vias to an inner plane to keep theta-JA around 35 C/W at 5-A continuous charge.
Estimated: At 12-V VIN, 8.4-V V_BAT, and 5-A charge, the converter delivers 42 W of charge power with ~93% efficiency, dissipating ~3.1 W in the IC. With a 35 C/W theta-JA on a 4-layer JEDEC test PCB this means a delta-T of ~108 C above 25 C ambient. Reduce charge current or improve copper if ambient exceeds 50 C inside the enclosure.
Always enable the I²C watchdog in firmware before final ship because an SDA/SCL stuck low can leave the charger in an indeterminate state. Validate input MPPT periodic sweep interval against the source - panels smaller than 5 W can be perturbed heavily by the MPPT step. Use the TI BQStudio GUI to dump the charger's status registers and verify JEITA temperature loops engage during fast charge.
コンプライアンス情報
RoHS and Pb-free per TI product page. Not AEC-Q100 qualified - this part targets consumer/industrial USB-C and solar applications, not automotive. Halogen-free status was not surfaced in verified web data.
