Overview
The INA239, produced by Texas Instruments, is an ultra-precise digital power monitor designed specifically for current-sensing applications. It features a high-resolution 16-bit delta-sigma ADC, enabling accurate measurements of current, bus voltage, temperature, and power. The device supports a wide common-mode range from –0.3 V to +85 V and can measure full-scale differential inputs of ±163.84 mV or ±40.96 mV across a resistive shunt sense element. The INA239 is known for its low offset and gain drift, making it suitable for precise systems without the need for multi-temperature calibration during manufacturing.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| ADC Resolution | 16-bit | |
| Offset Voltage | ±5 µV (maximum) | µV |
| Offset Drift | ±0.02 µV/°C (maximum) | µV/°C |
| Gain Error | ±0.1% (maximum) | % |
| Gain Error Drift | ±25 ppm/°C (maximum) | ppm/°C |
| Common Mode Rejection | 140 dB (minimum) | dB |
| Power Monitoring Accuracy | 0.7% full scale, –40°C to +125°C (maximum) | % |
| Alert Response Time | 75 µs | µs |
| Common-Mode Input Range | –0.3 V to +85 V | V |
| Bus Voltage Input Range | 0 V to 85 V | V |
| Shunt Full-Scale Differential Range | ±163.84 mV / ±40.96 mV | mV |
| Input Bias Current | 2.5 nA (maximum) | nA |
| Temperature Sensor Accuracy | ±1°C (maximum at 25°C) | °C |
| Supply Voltage | 2.7 V to 5.5 V | V |
| Operational Current | 640 µA (typical) | µA |
| Shutdown Current | 5 µA (maximum) | µA |
| SPI Communication Interface | 10 MHz | MHz |
Key Features
- High-resolution 16-bit delta-sigma ADC for precise current, voltage, and power measurements.
- Low offset voltage (±5 µV maximum) and low gain drift (±25 ppm/°C maximum) for accurate measurements across a wide temperature range.
- Wide common-mode range from –0.3 V to +85 V and bus voltage sense input from 0 V to 85 V.
- Fast alert response time of 75 µs.
- Integrated temperature sensor with ±1°C accuracy at 25°C.
- Programmable ADC conversion times from 50 µs to 4.12 ms and sample averaging from 1x to 1024x to reduce noise.
- Low input bias current (2.5 nA maximum) allowing for larger current-sense resistors.
- 10-MHz SPI communication interface for easy integration with microcontrollers.
- Operates from a single supply of 2.7 V to 5.5 V with low operational and shutdown currents.
Applications
- DC/DC converters and power inverters.
- Industrial battery packs.
- Power-over-Ethernet (PoE) systems.
- Telecom equipment.
- Enterprise servers.
Q & A
- What is the ADC resolution of the INA239?
The INA239 features a high-resolution 16-bit delta-sigma ADC.
- What is the offset voltage of the INA239?
The offset voltage is ±5 µV (maximum).
- What is the common-mode rejection ratio of the INA239?
The common-mode rejection ratio is 140 dB (minimum).
- How fast is the alert response time of the INA239?
The alert response time is 75 µs.
- What is the temperature accuracy of the integrated temperature sensor?
The temperature accuracy is ±1°C (maximum at 25°C).
- What is the supply voltage range for the INA239?
The device operates from a single supply of 2.7 V to 5.5 V.
- What is the typical operational current of the INA239?
The typical operational current is 640 µA.
- What is the maximum shutdown current of the INA239?
The maximum shutdown current is 5 µA.
- What communication interface does the INA239 use?
The device uses a 10-MHz SPI communication interface.
- What are some common applications of the INA239?
Common applications include DC/DC converters, industrial battery packs, Power-over-Ethernet (PoE) systems, telecom equipment, and enterprise servers.
