INA237
- High-resolution, 16-bit delta-sigma ADC
- Current monitoring accuracy:
- Offset voltage: ±50 µV (maximum)
- Offset drift: ±0.02 µV/°C (maximum)
- Gain error: ±0.3% (maximum)
- Gain error drift: ±50 ppm/°C (maximum)
- Common mode rejection: 120 dB (minimum)
- Power monitoring accuracy:
- 1.6% full scale, –40°C to +125°C (maximum)
- Fast alert response: 75 µs
- Wide common-mode range: –0.3 V to +85 V
- Bus voltage sense input: 0 V to 85 V
- Shunt full-scale differential range: ±163.84 mV / ±40.96 mV
- Input bias current: 2.5 nA (maximum)
- Temperature sensor: ±1°C (maximum at 25°C)
- Programmable conversion time and averaging
- 2.94-MHz high-speed I2C interface with 16 pin-selectable addresses
- Operates from a 2.7-V to 5.5-V
supply:
- Operational current: 640 µA (typical)
- Shutdown current: 5 µA (maximum)
The INA237 is an ultra-precise digital power monitor with a 16-bit delta-sigma ADC specifically designed for current-sensing applications. The device can measure a full-scale differential input of ±163.84 mV or ±40.96 mV across a resistive shunt sense element with common-mode voltage support from –0.3 V to +85 V.
The INA237 reports current, bus voltage, temperature, and power, all while performing the needed calculations in the background. The integrated temperature sensor is ±1°C accurate for die temperature measurement and is useful in monitoring the system ambient temperature.
The low offset and gain drift design of the INA237 allows the device to be used in precise systems that do not undergo multi-temperature calibration during manufacturing. Further, the very low offset voltage and noise allow for use in A to kA sensing applications and provide a wide dynamic range without significant power dissipation losses on the sensing shunt element. The low input bias current of the device permits the use of larger current-sense resistors, thus providing accurate current measurements in the micro-amp range.
The device allows for selectable ADC conversion times from 50 µs to 4.12 ms as well as sample averaging from 1x to 1024x, which further helps reduce the noise of the measured data.
技術文件
設計與開發
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INA228_237_238EVM — INA228、INA237 和 INA238 評估模組
此評估模組 (EVM) 是一款易於使用的平台,可評估 INA228、INA237 或 INA238 的主要功能與性能。
EVM 支援高達 10-A 的電流量測,並隨附圖形使用者介面 (GUI) 支援,可讀取及寫入裝置暫存器。
ASC-STUDIO-INA237 — ASC studio (SysConfig) for configuring all aspects of the INA237 current sensor
ANALOG-ENGINEER-CALC — PC software analog engineer's calculator
類比工程師的計算機旨在加速類比電路設計工程師定期使用的許多重複計算。此基於 PC 的工具提供圖形介面,列出各種常見計算,從使用回饋電阻器設定運算放大器增益到選擇適當的電路設計元件以穩定類比數位轉換器 (ADC) 驅動緩衝電路。
除了作為獨立工具使用外,此計算機還與類比工程師口袋參考中描述的概念相得益彰。
CS-AMPLIFIER-ERROR-TOOL — Current Sense Amplifier Comparison and Error Tool
SBOR021 — Power Monitor Tool
PMP23365 — 具備外部熱插拔及遙測功能的 24V、3A 8 類 PoE PD 參考設計
此參考設計利用 24V 與 3A 輸出實作乙太網路供電 (PoE) 電源裝置 (PD) 主動箝位順向式轉換器。配備整合式脈衝寬度調變器 (PWM) 控制器的 TPS23730 PD 可提供所有必要功能,以實現主動箝位順向式轉換器的 PoE PD 與 PWM 控制。此設計使用二次側調節 (SSR) 和光耦合器回饋。增加外部熱插拔以實現 7 類與 8 類 PD 應用。一次側使用 INA237 來監控 DC/DC 輸入電壓和電流,電源資訊則會由 I2C 隔離器或光耦合器架構電路傳送至二次側。
PMP23366 — 具有平順轉換和遙測功能的雙輸入備援 PoE Class 6 PD 參考設計
此設計實作乙太網路供電 (PoE) 第 6 類供電產品 (PD),搭載雙備援 PoE 輸入,可在這些輸入與輔助輸入間順暢轉換。使用兩個 TPS2372-3 PD 控制器進行高達 51W 的高功率 PoE 控制。5V 9A 主動箝位順向式轉換器隨 TPS23734 IC 的 PWM 部分實作。INA237A 透過 I2C 提供輸入電壓/電流/功率/溫度量測。
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| VSSOP (DGS) | 10 | Ultra Librarian |