NSC2860
NSC2860 is a high-side current sense amplifier with 100V common-mode range, 3% accuracy, and dedicated output...
Product Overview
Description
The NSC2860 is a high-side current sense amplifier designed for battery management, power supply monitoring, and motor control applications requiring accurate current measurement.
With 100V common-mode voltage range, the NSC2860 can monitor current in high-voltage systems without needing isolated supplies or level shifting circuits.
The integrated amplifier with fixed gain simplifies design and provides consistent accuracy across production volumes without precision resistor matching.
Product Series
NSC
Primary Application
Battery management systems
Key Features
- 100V common-mode voltage range
- 3% accuracy over temperature
- 400kHz bandwidth for fast transient monitoring
- Fixed 50V/V gain simplifies design
- Rail-to-rail output compatible with ADC inputs
- Wide supply voltage: 3V to 60V
- Low power consumption: 1mA
- SOT23-6 space-saving package
Specifications
| Supply Voltage | 3V to 60V |
|---|---|
| Common-Mode Range | 0V to 100V |
| Bandwidth | 400kHz |
| Accuracy | 3% (over temperature) |
| Gain | 50V/V (fixed) |
| Sense Voltage Range | 0V to 250mV |
| Output Swing | Rail-to-rail |
| Operating Temperature | -40C to +125C |
| Package | SOT23-6 |
Applications
Battery management systems
Battery and charging management
DC-DC converter current sense
Power conversion and supply
Motor control current monitoring
Motor drive and control systems
Overcurrent protection
Electronic system design
Power supply monitoring
Power conversion and supply
FAE Expert Insights
"The NSC2860 has become essential in my power supply and motor control designs for accurate current monitoring. What I appreciate most is the 100V common-mode range - in a recent 48V battery management system project, this allowed direct connection to the high-side of the battery stack without expensive isolated amplifiers or complex level shifting. The 3% accuracy over temperature is adequate for most monitoring and protection functions, though for precise Coulomb counting I'd add calibration. The 400kHz bandwidth enables monitoring of fast load transients, which is critical for detecting short circuits or motor stall conditions. The fixed 50V/V gain simplifies design significantly - we no longer need precision matched resistor networks. For overcurrent protection applications, I've implemented fast-acting protection by connecting the output to a comparator with <1us response time, well within the NSC2860's capability."
100V common-mode range enables simple high-voltage current monitoring without isolation
— David Chen, BeiLuo
Frequently Asked Questions
How do I select the sense resistor value for NSC2860?
Sense resistor selection balances accuracy, power loss, and voltage headroom: Maximum sense voltage should stay below 250mV at full-scale current. Calculate R_sense = 250mV / I_max. For example, for 10A max current: R_sense = 250mV / 10A = 25mohm. Power dissipation: P = I_rms^2 x R_sense. At 10A continuous, P = 100 x 0.025 = 2.5W, requiring appropriate resistor wattage rating. For 3% accuracy, the sense voltage should be at least 10x the input offset voltage referred to input (RTI) of NSC2860. At 3% accuracy, RTI is approximately 3mV. The NSC2860's output noise of 28uV RMS (in 0.1Hz to 10Hz) sets a practical minimum sense voltage for high-resolution applications. I recommend starting with the highest practical sense resistor value that keeps power dissipation acceptable, then verify accuracy meets your requirements.
Calculate R_sense based on max current and 250mV limit. Choose resistor with adequate power rating (2x calculated dissipation). Verify accuracy with your specific accuracy requirements.
What is the difference between high-side and low-side current sensing?
High-side sensing (NSC2860) measures current between the positive supply and the load, while low-side sensing measures between load and ground. High-side advantages: Detects load shorts to ground that low-side cannot see. Maintains cleaner ground reference for the load. Required for battery management where ground is floating. High-side challenges: Requires high common-mode voltage capability (NSC2860 handles 100V). More susceptible to supply transients. Slightly more complex measurement. Low-side advantages: Simple ground-referenced measurement. Lower common-mode voltage allows simpler amplifiers. Low-side challenges: Adds voltage drop in ground path. Cannot detect shorts to positive supply. Load ground is elevated from system ground. For battery management, motor control, and safety-critical systems, high-side sensing with NSC2860 is preferred despite the complexity.
Use NSC2860 high-side sensing for battery systems, motor control, and safety applications. Low-side is acceptable for simple power supply monitoring where ground elevation is acceptable.
How does NSC2860 handle fast transient currents in motor control?
The NSC2860's 400kHz bandwidth captures fast current transients with the following considerations: For PWM motor control at 20kHz switching, the fundamental frequency is well within the 400kHz bandwidth. Harmonics above 400kHz will be attenuated, but this is typically acceptable as they is switching noise rather than motor current. The NSC2860's propagation delay of approximately 1us means the output tracks the input with 1us lag - adequate for overcurrent protection response times of 10-100us. For detecting motor stall or short-circuit conditions, the NSC2860 can drive a fast comparator for <1us total fault response. If you need faster response, consider adding a hardware comparator after the NSC2860 output. The output stage can drive 2kohm loads, sufficient for most ADC inputs and comparator circuits.
NSC2860 bandwidth handles PWM frequencies up to 50kHz. For overcurrent protection, add external comparator. Verify transient response with your specific motor and PWM frequency.
What accuracy can I expect from NSC2860 and how does temperature affect it?
The NSC2860 specifies 3% total accuracy over the full temperature range from -40C to +125C, which includes: Input offset voltage contribution (approximately 0.5mV RTI at 25C, increases with temperature). Gain error (typically 0.5% at 25C). Gain drift with temperature (typically 50ppm/C). CMRR effect on accuracy (typically negligible at 100V/100V = 1). The 3% specification is the worst-case over temperature. At room temperature, accuracy is typically 1-1.5%. For applications requiring better accuracy, you can implement system calibration: Measure and store zero-current offset at system startup. Apply correction factor based on expected temperature range. For precision applications requiring <1% accuracy, consider NSC2862 with 1% accuracy or INA240 with 0.2% accuracy.
Expect 3% accuracy over full temperature range. For 1% accuracy, use NSC2862. For <0.5% accuracy, use INA240 or implement system calibration with NSC2860.
Can NSC2860 be used in automotive battery management systems?
Yes, Novosense offers the NSC2860-Q1 with AEC-Q100 Grade 1 qualification for automotive applications. The automotive version meets stringent requirements: AEC-Q100 Grade 1 qualification (-40C to +125C). Full PPAP documentation support. IATF 16949 manufacturing certification. Enhanced reliability for automotive lifetime requirements. Automotive BMS applications for NSC2860-Q1 include: Battery pack current monitoring for charge/discharge measurement. Cell balancing current sensing. Pre-charge circuit monitoring. Contact weld detection. The 100V common-mode range is sufficient for 48V mild hybrid systems. For 400V and 800V EV batteries, higher voltage variants or isolated sensing is required. Contact BeiLuo for NSC2860-Q1 availability and automotive pricing, and request PPAP documentation for your automotive qualification process.
For automotive BMS, specify NSC2860-Q1 with AEC-Q100 Grade 1 qualification. Request PPAP Level 3 documentation. For 48V systems, NSC2860-Q1 is suitable. For higher voltage, consider isolated solutions.