High Reliability Reinforced Isolated Amplifier NSI1611

With high-accuracy performance, robust isolation capability, and flexible input/output configurations, the solution optimizes high-voltage sensing in server power supplies from three key dimensions—measurement accuracy, isolation safety, and system cost—while supporting high-frequency power architectures based on SiC and GaN technologies.

The NSI1611 is NOVOSENSE’s high-performance capacitive isolation amplifier, leveraging capacitive isolation technology to deliver excellent immunity to magnetic interference. It supports a 0.01–4 V single-ended input and single-ended output, eliminating the need for an external differential-to-single-ended conversion stage. With low offset and low gain drift, the device ensures high measurement accuracy across the full operating temperature range. Its high input impedance makes it well suited for interfacing with high-impedance signal sources, while its high common-mode transient immunity (CMTI) enables accurate signal measurement in high-power switching environments such as motor control applications.

The NSI1611 is a high-performance isolated amplifier with output separated from input based on NOVOSENSE capacitive isolation technology, which provides the amplifier with exceptional resistance to magnetic interference. The device accepts a single-ended voltage input of 0.01-4V and provides a single-ended output which can help to reduce the external differential to single ended amplifier. The low offset and gain drift ensure the accuracy over the entire temperature range. The NSI1611 features high input impedance, making it an ideal choice for applications where large resistive dividers are used or when connecting any high-impedance voltage signal source to the input. The high common-mode transient immunity ensures that the device is able to provide accurate and reliable measurements even in the presence of high-power switching such as in motor control applications.

Features

• Up to 5700Vrms Insulation voltage
• 0.01~4V linear Input Voltage Range
• Single-Ended Output with Adjustable Gain:

       - Gain = 0.2* VREFIN
       - VREFIN = 5.0V recommended for best accuracy

• Low Offset Error and Drift: ±1.5mV (Max), ±45μV/°C (Max)
• Low Gain Error and Drift: ±0.25% (Max), ±35ppm/°C (Max)
• Low Nonlinearity and Drift: ±0.04% (Max), ±1ppm/°C (Typ)
• SNR: 82dB (Typ, BW=10kHz), 71dB (Typ, BW=100kHz)
• Wide bandwidth: 330kHz (Typ)
• High CMTI: 150kV/μs (Typ)
• Operation Temperature: -40°C ~125°C
• RoHS-Compliant Packages: SOP8 (300mil)
• UL recognition: 5700Vrms for 1 minute per UL1577
• CQC certification per GB4943.1
• CSA component notice 5A
• DIN EN IEC 60747-17 (VDE 0884-17)

Application

• Motor Drives
• Server Power Supply Units
• Energy Storage Systems
• Solar Inverters
• Charging Piles

Block Diagram