TPS2121RUX - 22V 4.5A Priority Power MUX | Texas Instruments
部品番号: TPS2121RUX ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.42 | $14.20 |
| 100 | $1.08 | $108.00 |
| 500 | $0.86 | $430.00 |
| 1,000 | $0.69 | $690.00 |
| 3,000 | $0.55 | $1,650.00 |
TPS2121RUX 概要
A power multiplexer is a load-sharing/redundancy switch that allows a system to draw power from one of two sources with priority logic, automatic switchover, and in-rush control. The TPS2121 belongs to the ORing controller / power MUX / load-switch product hierarchy, sitting between discrete MOSFET ORing designs (anode-to-cathode diodes or ideal-diode controllers) and full PMIC solutions. It integrates dual back-to-back N-channel MOSFETs, priority arbitration, adjustable current limit, soft-start, and seamless fast switchover (< 5 µs) inside a tiny QFN footprint, eliminating dozens of discrete components.
Key features include 2.7-V to 22-V operating input range, 56-mΩ per-channel Rds(on), 4.5-A continuous current capability, adjustable current limit (ILIM), seamless switchover within 5 µs, and a logic-controlled priority mode (PR1 = High → IN1 priority; PR1 = Low → IN2 priority). The VQFN-HR-12 (RUX) package has an exposed thermal pad (PowerPAD) for low thermal resistance, supporting up to ~2 W continuous dissipation on a modest PCB copper pour. The device operates over -40 °C to +125 °C junction temperature and is characterized for industrial-grade environments.
The architecture uses TI's priority-based power-path control: the device continuously compares IN1 and IN2 voltages against an internal reference (2.5 V typical on PR1) and switches to the higher-priority source when it is valid. During switchover, internal break-before-make control prevents cross-conduction; the output is held up by output capacitance during the brief (~5 µs) transition. The current-limit and soft-start blocks protect against in-rush spikes when a freshly-selected source is brought online.
Typical applications include redundant power rails in industrial PLCs and factory automation, backup battery switching in portable medical and IoT devices, USB-C PD source multiplexing, multi-battery Point-of-Sale (POS) terminals, and automatic transfer of AC adapters versus battery in notebook docking stations. The compact 2 mm × 2.5 mm footprint makes it ideal for space-constrained designs that previously required a discrete ORing controller plus two MOSFETs.
When designing with the TPS2121, place input and output ceramic capacitors as close as possible to the IC pins (10 µF minimum on IN1, IN2, and OUT recommended) to minimize voltage droop during switchover. Use the PR1 resistor divider to set the VIN1 priority threshold, set ILIM with an external resistor (RILIM = K / ILIM), and provide adequate copper area on the PowerPAD for thermal dissipation. Avoid parallel connection of multiple TPS2121 units - one device per system is standard.
This page synthesizes distributor pricing, drop-in alternatives, prioritized selection guidance, and practical PCB layout notes that go beyond a typical manufacturer datasheet summary.
ドロップイン代替品: TPS2121RUX — 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:
TPS2120RUX
✅ ドロップイン📋 参考代替品（カタログ未掲載）
TPS2121RUXR
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TPS2120RUXR
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TPS2121RUXT
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
TPS2120RUXT
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
TPS2121RUX 最大定格＆電気的特性
| Product Type | Priority Power Multiplexer (Power MUX) |
| トポロジー | Dual-Input, Single-Output (DISO), 2:1 |
| Number of Inputs | 2 (IN1, IN2) |
| 出力数 | 1 (OUT) |
| Input Voltage Range (IN1, IN2) | 2.7 V to 22 V |
| 出力電圧範囲 | 2.7 V to 22 V |
| Continuous Load Current | 4.5 A |
| On-Resistance (per channel, typ.) | 56 mΩ |
| Switchover Time | 5 µs (typical, fast switchover) |
| 電流制限 | Adjustable via external resistor |
| Priority Control | Logic-controlled via PR1 pin (IN1 or IN2 priority) |
| 静止電流 | 200 µA (typical) |
| 動作温度範囲 | -40 °C to +125 °C |
| パッケージ | VQFN-HR-12 (RUX) 2.0 mm × 2.5 mm |
| 実装タイプ | Surface Mount |
| MSLレベル | 2 (per JEDEC J-STD-020) |
| RoHS ステータス | Compliant |
TPS2121RUX ピン構成
| ピン 1 | IN1 — Input 1 power source (MOSFET drain) |
| ピン 2 | IN1 — Input 1 power source (MOSFET drain) |
| ピン 3 | GND — Ground reference |
| ピン 4 | ST — Status / fault output (open-drain) |
| ピン 5 | ILIM — Current-limit set resistor |
| ピン 6 | PR1 — Priority 1 / VIN1 threshold (resistor divider) |
| ピン 7 | OUT — Power output (MOSFET source) |
| ピン 8 | OUT — Power output (MOSFET source) |
| ピン 9 | OUT — Power output (MOSFET source) |
| ピン 10 | IN2 — Input 2 power source (MOSFET drain) |
| ピン 11 | IN2 — Input 2 power source (MOSFET drain) |
| ピン 12 | IN2 — Input 2 power source (MOSFET drain) |
主な用途
TPS2121RUX の用途: 6 件s: Redundant Industrial PLC Power Rails, USB-C Power Delivery Source Multiplexing, Multi-Battery Point-of-Sale (POS) Terminals, Notebook Docking Station Adapter/Battery Switchover, Backup Battery Switching for IoT Edge Gateways, Medical Device Dual-Rail Redundancy.
Redundant Industrial PLC Power Rails
The TPS2121RUX is well suited for redundant industrial PLC and factory-automation power rails: its 2.7 V-22 V input range covers common 5 V, 12 V, and 24 V industrial buses, and the 56 mΩ on-resistance keeps steady-state losses below ~1 W at 4 A load. Placed between a primary 24 V backplane rail and a backup battery or UPS output, the device switchover completes within 5 µs, fast enough to ride through brief outages without resetting the PLC CPU. The exposed-pad 12-VQFN-HR package (2.0 mm × 2.5 mm) occupies minimal PCB area, allowing drop-in replacement of much larger diode-OR circuits built from discrete Schottky diodes or LM5050 ORing controllers.
おすすめ
USB-C Power Delivery Source Multiplexing
In USB-C Power Delivery designs that must switch between an adapter input and a battery source, the TPS2121RUX provides a compact ORing switch with 22 V tolerance - sufficient for the 20 V PD profile used by laptops and tablets. The device's seamless switchover (~5 µs) is faster than typical PD contract re-negotiation, so the downstream PD controller never sees a glitch. The 56 mΩ per-channel Rds(on) keeps efficiency above 95 % at 3 A load, and the integrated adjustable current limit (set via ILIM resistor) protects against in-rush when a fresh PD source is selected. Use one TPS2121 per USB-C port to keep ports electrically independent.
おすすめ
Multi-Battery Point-of-Sale (POS) Terminals
The TPS2121RUX is a strong choice for multi-battery POS terminals that must hot-swap between a main Li-ion pack, a coin-cell backup, and an AC adapter: its 2.7 V-22 V range handles all three sources with a single device, and the integrated soft-start eliminates the in-rush spikes that would otherwise trip upstream USB or adapter current limits. In a typical POS architecture, the TPS2121 sits between the three power sources and the 5 V system rail, picking the highest-priority valid source via the PR1 pin. The exposed-pad package keeps the junction temperature low even at continuous 4 A throughput, and the 5 µs switchover preserves the terminal's Wi-Fi/Bluetooth link during a battery-to-adapter transition.
おすすめ
Notebook Docking Station Adapter/Battery Switchover
The TPS2121RUX supports seamless adapter-to-battery switchover in notebook docking stations: when the dock is unplugged from its AC adapter, the device automatically switches to the laptop's battery feed within 5 µs, providing enough hold-up margin for the laptop's internal power-management IC to ramp up its battery rail without dropping the dock's USB, Ethernet, or display ports. The 4.5 A continuous rating covers dock-power-hungry peripherals (USB-PD charging, multiple USB-SS ports, 2.5 GbE), and the 56 mΩ Rds(on) ensures thermal performance stays manageable in the dock's confined chassis. The 12-VQFN-HR footprint is small enough to fit alongside a Type-C connector and an ESD array on the dock PCB.
おすすめ
Backup Battery Switching for IoT Edge Gateways
In industrial IoT edge gateways that must keep running through brownouts and brief outages, the TPS2121RUX provides a compact, thermally efficient backup-path switch between the main DC supply and a backup Li-ion or super-capacitor bank. The 2.7 V-22 V range accepts any standard industrial 12-24 V input, and the 56 mΩ Rds(on) keeps efficiency above 96 % at typical 2 A gateway loads. The 5 µs seamless switchover preserves the LTE/5G modem link, and the exposed-pad package minimizes PCB area - critical for compact DIN-rail or panel-mount enclosures. Use the ILIM pin to cap in-rush when a depleted backup battery is suddenly placed on the bus.
おすすめ
Medical Device Dual-Rail Redundancy
Medical devices such as portable patient monitors and infusion pumps increasingly demand redundant power sources for safety and uptime, making the TPS2121RUX an appropriate ORing element between an AC adapter and a primary Li-ion battery: its 2.7 V-22 V input range handles 5 V and 12 V adapter rails, the 56 mΩ on-resistance minimizes heat dissipation at 2-3 A continuous loads, and the seamless switchover keeps the monitor's display, processor, and wireless link live during a power-source swap. The exposed-pad QFN package allows the device to dissipate ~2 W safely on a small copper pour, and its -40 °C to +125 °C operating range covers clinical and storage environments.
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: TPS2121RUX — 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 | TPS2120RUX | TPS2121RUXR | TPS2120RUXR | TPS2121RUXT | TPS2120RUXT |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | VQFN-HR-12 (RUX) 2.0x2.5 mm | VQFN-HR-12 (RUX) 2.0x2.5 mm - same | VQFN-HR-12 (RUX) 2.0x2.5 mm - same | VQFN-HR-12 (RUX) 2.0x2.5 mm - same | VQFN-HR-12 (RUX) 2.0x2.5 mm - same | VQFN-HR-12 (RUX) 2.0x2.5 mm - same |
| Continuous Output Current | 4.5 A | 2.5 A | 4.5 A | 2.5 A | 4.5 A | 2.5 A |
| Input Voltage Range | 2.7 V to 22 V | 2.7 V to 22 V | 2.7 V to 22 V | 2.7 V to 22 V | 2.7 V to 22 V | 2.7 V to 22 V |
| Switchover Time | 5 µs (typical) | 5 µs (typical) | 5 µs (typical) | 5 µs (typical) | 5 µs (typical) | 5 µs (typical) |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
| RoHS / Pb-Free | Yes | Yes | Yes | Yes | Yes | Yes |
| Pin Configuration | Standard RUX pinout | Standard RUX pinout - pin-to-pin compatible | Standard RUX pinout - pin-to-pin compatible | Standard RUX pinout - pin-to-pin compatible | Standard RUX pinout - pin-to-pin compatible | Standard RUX pinout - pin-to-pin compatible |
主な差別化要因
- Higher peak current in identical footprint （vs TPS2120RUX)
- Seamless < 5 µs switchover eliminates output capacitance bulk （vs Discrete Schottky ORing diode pair)
- Adjustable current limit with internal MOSFETs （vs External MOSFET + LM5050 ORing controller)
設計ノート
Place 10 µF ceramic input/output capacitors as close as possible to each of the IN1, IN2, and OUT pins; this minimizes voltage droop during the ~5 µs switchover window. Use X7R or X5R dielectrics rated for the full input voltage (e.g., 25 V or 50 V parts at a 22 V max input). For high-transient loads, parallel 0.1 µF decoupling capacitors directly at each pin to suppress ringing.
Estimated: at 4.5 A continuous current through a single 56 mΩ channel, internal dissipation is P = I² × Rds(on) = 4.5² × 0.056 ≈ 1.13 W. The VQFN-HR-12 (RUX) thermal pad (PowerPAD) should be soldered to at least ~100 mm² of inner-layer copper (1-oz or 2-oz) to keep junction temperature rise below ~30 °C at 25 °C ambient. At lower currents the device runs comfortably without additional copper, but sustained 4 A loads require a 1-oz copper pour covering the full underside of the package footprint.
Do not confuse PR1 (priority select threshold) with the EN pin - the TPS2121 has no dedicated enable. PR1 is set by an external resistor divider on IN1; when PR1 < 1 V the device defaults to IN2 priority, when PR1 > VREF (~2.5 V) it switches to IN1 priority. Choose RPR1 values large enough (100 kΩ or more) to avoid loading IN1, and add a 100 nF filter cap to PR1 if the divider is on a noisy rail. Do not parallel multiple TPS2121 devices to increase current - one device per system is standard.
Route IN1, IN2, and OUT traces as wide as possible (≥ 1 oz copper, ≥ 30 mil wide at 4.5 A) directly into the exposed pad pours. Keep the PR1 and ILIM traces short and isolated from switching-current paths. The status (ST) pin is open-drain and can pull up to any logic rail up to 6 V - place the pull-up close to the receiving MCU GPIO, not at the TPS2121 end, to minimize noise pickup.
コンプライアンス情報
RoHS and REACH compliance confirmed via TI product page. Not AEC-Q100 qualified - the TPS2121 family targets industrial / commercial applications. Halogen-free per TI's Pb-Free/Halogen-Free policy.
