System Role & When to Pick Fluxgate Closed-Loop

A fluxgate closed-loop current transducer is an isolated current sensor that drives a magnetic core and feedback winding so that the net flux stays close to zero while a secondary current accurately mirrors the primary current. It targets tens to hundreds of amperes in DC-links and motor phases, offering sub-percent accuracy over temperature and reinforced galvanic isolation for high-voltage converters and grid-tied systems.

If you only need a few amperes and can tolerate shunt losses, a resistor plus amplifier is cheaper and simpler (see Low-Side Shunt Current Sense Amp). Open-loop Hall sensors fit cost-sensitive isolated sensing. Fluxgate closed-loop devices justify their higher cost when you need high accuracy, low drift, and robust isolation on high-current rails. For AC-only large currents without DC, a Rogowski solution may be more suitable.

In real systems, one fluxgate transducer often serves multiple roles: fast DC-link protection, accurate phase current feedback for field-oriented motor control, and stable DC/current data for power and energy metering. This page focuses on the device itself; system-level protection, control and metering frameworks are covered in their respective pages within the Current Sensing domain.

Fluxgate Sensing & Zero-Flux Closed Loop

Fluxgate Core & Excitation

A fluxgate transducer uses a non-linear magnetic core driven by an AC excitation winding. The excitation waveform moves the operating point into positive and negative regions of the B–H curve, sweeping through saturation every half-cycle. With no DC flux from the primary conductor, this magnetisation pattern remains symmetric; any primary DC current breaks this symmetry.

• Non-linear B–H curve with distinct saturation zones
• AC excitation drives core into ± saturation each cycle
• Symmetric magnetisation when DC flux = 0
• Primary DC current shifts symmetry and alters harmonic content

Detection, Demodulation & Offset

A sense winding picks up the distorted excitation waveform. The harmonic components of this waveform depend on the DC flux imposed by the primary current. Synchronous detection and demodulation extract these harmonics and convert them into a low-frequency error signal representing flux imbalance inside the core.

Even at zero primary current, offsets arise from several mechanisms. Understanding them defines minimum detectable current and calibration intervals.

• Residual magnetisation and asymmetric excitation
• Core/winding tolerances across production & temperature
• Front-end offsets and finite demodulation accuracy

Compensation Winding & Zero-Flux Loop

Instead of using the demodulated signal directly as output, the transducer drives a compensation winding. A loop amplifier injects current until the core flux is forced back toward zero. Under this zero-flux condition, the compensation current becomes a precise, isolated replica of the primary current.

Loop gain and compensation determine rebalancing speed, residual flux, and transient behaviour. These concepts form the basis for the bandwidth, stability, and saturation behaviour discussed in later sections.

Output Typologies: Current, Voltage & Digital

Manufacturers expose the compensation loop in different forms. Some provide a secondary current that requires an external burden resistor. Others integrate burden and amplifier to deliver a voltage output. Newer devices digitise the signal internally and expose it over I²C or SPI for system telemetry.

For shunt-based voltage/current telemetry with digital output, see the Digital Current Monitor (I²C/SPI) page.

Key Parameters & Selection Trade-Offs

Measurement Range & Linearity

Fluxgate closed-loop transducers span ±20 A to beyond ±1000 A depending on core size and compensation capability. Larger cores and heavier compensation currents support higher peak currents, while maintaining sub-percent linearity over temperature and supply variations. Linearity is usually specified as a percentage of full scale and combines core behaviour, loop gain and mechanical placement around the primary conductor.

For selection, allow 20–50 percent margin above the system’s maximum continuous current. For fast protection loops the peak current rating matters more than static accuracy, while control-loop feedback requires tighter linearity with lower drift across temperature.

• Check continuous vs peak current requirements
• Verify linearity in %FS across temperature
• Account for conductor placement tolerance
• Consider margin for fault or transient conditions

Accuracy, Offset & Stability

Closed-loop transducers achieve high accuracy through strong loop gain and symmetric demodulation. Total error comprises offset, gain error, temperature drift and long-term drift. Offset is set by core balance, excitation symmetry and analog front-end limits. Gain accuracy depends on magnetic coupling, compensation resistor and amplifier gain. Temperature and aging contribute additional drift in both offset and gain.

Combined error ≈ Offset + (Gain × Current) + Temp drift + Long-term drift

Bandwidth (Static Definition)

Datasheet bandwidth reflects loop gain, compensation and magnetic dynamics. Typical fluxgate closed-loop bandwidth ranges from 10 kHz to 100 kHz. High bandwidth supports fast control and protection loops, but increases noise and tightens loop-stability constraints. Small-signal bandwidth is distinct from large-signal transient behaviour, which is covered in the Dynamic Behaviour section.

Large-signal response, saturation & recovery → see next section (#dynamic)

Noise & Filtering

Noise arises from demodulation residuals, burden resistor thermal noise and magnetic coupling. Filtering may be required to align noise with system ADC resolution or metering bandwidth. External RC filters or digital averaging in the controller are common solutions.

• Noise contributors: demod residuals, burden resistor, core noise, wiring
• Filter options: output RC, digital LPF, oversampling
• Balance response time vs stability vs ADC resolution

Isolation Ratings

Isolation performance is defined by basic/reinforced insulation ratings, working voltage, hi-pot withstand and common-mode transient immunity (CMTI). These parameters determine suitability for grid-tied systems and EV traction inverters where fast dV/dt events are common.

Creepage/clearance & insulation classes → see EMC & Safety section

Thermal Limits & Power Dissipation

Thermal behaviour is governed by compensation current, burden resistor power and internal excitation losses. High currents increase compensation effort and heat dissipation. Industrial-grade devices typically support −40 °C to 85 °C; automotive variants extend to −40 °C to 125 °C with derating applied at high ambient temperatures.

• Check burden resistor power at peak compensation current
• Verify internal excitation power dissipation
• Confirm ambient derating curves
• Fully enclosed modules may require airflow or heatsinking

Dynamic Behaviour, Saturation & Fault Handling

Closed-Loop Dynamics & Rebalancing Behaviour

Closed-loop fluxgate transducers regulate the compensation current so that net magnetic flux stays near zero. When primary current changes, the demodulated error signal drives the loop amplifier, pushing compensation current to re-balance the core. Rebalancing speed, overshoot and settling time depend on loop gain, magnetic sensitivity and compensation network shaping.

Fast loops yield low latency and accurate phase information for control, but require careful gain shaping to avoid oscillation or excessive noise amplification. Slower loops reduce jitter but increase delay and may distort fast current edges. Manufacturers rarely expose full loop-transfer plots, so bandwidth and step-response figures become the practical indicators.

• Higher loop gain → faster rebalancing but risk of instability
• External burden and wiring affect loop phase margin
• Long cables may require damping RC near the output
• Datasheet small-signal bandwidth ≠ large-signal response

Large-Signal Events: Slew, Delay & Saturation

Large-signal current steps momentarily exceed the loop’s ability to restore zero flux. During this interval, the compensation current slews at a limited rate, set by amplifier current limits and magnetic dynamics. Output delay arises from this finite slew and the demodulation window used to extract flux imbalance.

When primary current exceeds the loop’s compensation capability, the core drifts out of the zero-flux central region and the device enters saturation. Saturation severely reduces accuracy until the loop recovers. Some modules provide saturation flags or fault outputs indicating when the core leaves its linear operating region.

• Slew-rate limit depends on compensation amplifier & magnetic coupling
• Demodulation interval adds fixed latency (kHz-range excitation)
• Saturation occurs when I_primary > I_comp,max
• Recovery time varies with core state & temperature

Fault Conditions & Protection Considerations

Under severe faults—short circuits, DC-link surges, shoot-through currents—the primary current may exceed compensation range instantly. In this regime the core saturates, the secondary current clips and output deviates from the true current waveform. Low-latency protection cannot rely on the transducer alone; a parallel shunt, fast DI/OC protection or desaturation detection is usually required in traction inverters and motor drives.

After fault removal, recovery time depends on how far the core was driven into saturation, magnetic hysteresis and the internal excitation waveform. Some devices integrate soft-reset logic or current-limit features in the compensation driver to speed up recovery. External burden resistor sizing also affects fault robustness.

• Fault currents >> nominal → immediate saturation
• Saturated core loses directionality until loop rebalances
• May trigger internal fault pin if available
• Protection loops should not rely solely on fluxgate feedback

Mechanical & PCB Integration

Mechanical Mounting: Orientation & Centering

Fluxgate core geometry is symmetric, and accuracy depends on placing the primary conductor as close to the geometric centre of the aperture as possible. Off-centre routing skews magnetic flux distribution, increasing linearity error and amplifying offset drift across temperature. Busbars should remain perpendicular to the aperture plane and maintain consistent height across builds.

Flat busbars, round wires and multi-strand conductors all behave differently inside the aperture. Flat busbars must be centred in the z-axis to avoid asymmetric flux. Multi-path or laminated conductors should be aligned so that current distribution remains predictable across variants and temperature.

• Keep conductor centred in aperture (x/y/z symmetry)
• Avoid tilted or angled busbars
• Maintain consistent mechanical height between units
• Ensure one single, well-defined current path

Conductor Routing: Single Path, No Return Loop

Only the intended primary current must pass through the aperture. Any return path through or near the core cancels part of the magnetic flux and distorts measurement. In three-phase systems, phase spacing and busbar arrangement should minimise cross-coupling between adjacent phases.

• Avoid return currents passing through or close to the aperture
• Separate forward and return paths physically
• Ensure phase conductors do not overlap magnetic fields
• Keep external high-current loops predictable and symmetric

PCB Placement & Secondary Routing

The secondary side of a fluxgate transducer behaves like a low-noise analog block. Burden resistors, RC filters and any loop-stability components must be placed close to the module pins to minimise parasitic inductance and external noise pickup. Keep outputs away from switching nodes, gate-drive routes and high-di/dt copper pours.

Stray Magnetic Fields & Interference

Fluxgate sensors are very sensitive to low-frequency magnetic fields. Place inductors, transformers, chokes and large switching loops at a safe distance. Ferromagnetic screws or brackets near the aperture disturb flux symmetry and should be avoided or replaced with non-magnetic hardware.

• Keep inductors and transformers at least 10–20 mm away
• Avoid ferromagnetic screws around the core
• Maintain symmetric phase-conductor layout
• Minimise exposure to strong external magnetic fields

Thermal Considerations

Busbar heating, internal excitation losses and compensation-loop power all contribute to temperature rise. Elevated temperature affects core balance, offset stability and long-term drift. Ensure adequate clearance from hot copper and provide airflow or heatsinking where required.

• Avoid mounting directly above high-temperature busbars
• Check burden resistor dissipation under peak compensation current
• Consider airflow for enclosed modules
• Monitor drift over temperature for calibration-sensitive systems

EMC Behaviour & Safety Integration

Conducted & Radiated EMC Behaviour

Fluxgate transducers sit close to high-current, high-dV/dt conductors and can both pick up and emit noise. On the primary side, the aperture surrounds the power path and is largely insensitive to high-frequency ripple as long as net ampere-turns are correctly routed. On the secondary side, excitation and compensation waveforms can couple into nearby traces if layout is careless.

For conducted EMC, keep the secondary return path compact and reference it to a quiet ground plane. Decoupling capacitors near the module supply pins help contain excitation currents. For radiated EMC, maintain distance from antenna-like structures such as long control cables, communication buses and poorly referenced shield connections.

• Minimise loop area of secondary-side supply and output paths
• Place decoupling close to supply pins with short returns
• Keep away from long unshielded control or I/O traces
• Validate noise margins during EMC testing, not only in lab benchtop setups

dV/dt, CMTI & Common-Mode Transients

In fast-switching inverters and converters, high dV/dt on the DC-link can inject common-mode currents through parasitic capacitances in the fluxgate module. Common-mode transient immunity (CMTI) specifies the maximum dV/dt the isolation barrier can withstand without corrupting measurement or violating insulation integrity.

Layout should route the primary conductor and its high-dV/dt nodes away from sensitive secondary traces. A well-defined reference for the secondary ground, plus short, direct ties to the controller, helps avoid common-mode voltage excursions on the measurement side during fast switching events.

• Verify module CMTI against inverter dV/dt and switching frequency
• Route high-dV/dt nodes away from secondary pins and traces
• Keep secondary reference tied to a low-impedance ground island
• Confirm measurement integrity under worst-case transient conditions

Creepage, Clearance & Insulation Coordination

Safety integration starts with creepage, clearance and insulation class compliance. The fluxgate module typically provides internal reinforced or basic insulation, but board-level creepage and clearance must be designed to match the target working voltage, pollution degree and over-voltage category.

Respect recommended keep-out zones around the module’s primary and secondary pins. Do not route copper features or pour planes into manufacturer-defined clearance gaps. If conformal coating or potting is used, coordinate its dielectric properties and thickness with the insulation design rules for your standard.

• Follow creepage/clearance guidelines for the target working voltage
• Keep copper and vias out of isolation slots and keep-out areas
• Account for pollution degree and over-voltage category in design
• Consider conformal coating effects in margin calculations

Shielding, Grounding & Reference Strategy

Some transducers provide shield pins or dedicated reference points for internal screening. Connect shields according to the manufacturer’s recommendation—often to the secondary-side reference plane at a single point. Improperly referenced shields can act as antennas and worsen radiated emissions.

The preferred strategy is a quiet analog ground island for the fluxgate secondary side, connected to the main ground at a controlled star point. Avoid routing digital return currents under the module. If cable shields are used on the secondary side, terminate them consistently and avoid multiple, uncontrolled shield connections.

• Use a quiet analog ground reference for the secondary side
• Connect shield pins as specified by the datasheet
• Avoid digital return paths underneath the module area
• Terminate cable shields at a defined, low-impedance point

Safety Standards & Test Planning

Fluxgate transducers are often deployed in systems targeted at standards such as industrial drive safety, grid-connected inverters or EV traction. While the device itself may carry certifications, system-level compliance still requires coordinated hi-pot, surge, ESD and EFT testing across the entire insulation path.

Build a test plan that exercises worst-case conditions: maximum working voltage, highest ambient temperature, worst pollution conditions and fast transients on both primary and secondary sides. Ensure that insulation margins are not only met on paper but verified with real hardware stress.

• Verify hi-pot levels and leakage limits at system level
• Include surge, ESD and EFT tests in qualification
• Test at maximum ambient and supply conditions
• Document insulation coordination and pass/fail criteria for audits

Self-Test, Calibration & Aging Diagnostics

Built-In Self-Test Hooks

Many fluxgate transducers include internal test features such as excitation monitor pins, fault outputs or dedicated self-test inputs. Self-test functions typically inject a known test current or emulate a flux imbalance so that the secondary signal chain and controller can verify integrity without applying real primary current.

At the minimum, monitor supply current, excitation status and fault pins at power-up. Where available, use built-in self-test modes during maintenance windows to confirm that the compensation loop and burden path respond as expected. Record test results in system logs for long-term health tracking.

• Use internal self-test input (if provided) to emulate known current
• Check fault pins for saturation, over-temperature or internal errors
• Verify supply current and excitation activity at start-up
• Log self-test results for trending over product lifetime

Offset & Gain Calibration

Offset calibration is often performed at zero primary current by sampling the output over a quiet window and subtracting the averaged value from subsequent measurements. Gain calibration requires a known reference current, applied either through the main bus or a controlled test path, and adjusting the digital scaling factor in the controller.

For high-accuracy systems, combine factory calibration with in-system trims. Factory calibration aligns the transducer and burden hardware; in-system calibration compensates for installation-specific effects such as conductor centring, external wiring and layout. Store calibration constants in non-volatile memory together with version and temperature information.

• Perform zero-current offset calibration at a stable temperature
• Use a traceable reference current for gain calibration
• Maintain separate offset and gain coefficients per range or mode
• Record calibration date, method and temperature for traceability

Temperature Behaviour & Drift Monitoring

Offset and gain vary with temperature due to core properties, winding resistance and analog front-end drift. Systems that operate over a wide ambient range should capture temperature alongside current readings to enable temperature-dependent compensation or at least to interpret residual error correctly.

A simple drift-monitoring strategy periodically re-runs zero-current offset checks at known operating points and compares results to initial calibration. Significant deviation can trigger warnings, reduced accuracy modes or maintenance flags. For metering applications, periodic in-field calibration may be mandatory.

• Log temperature with calibration and self-test results
• Define acceptable drift limits for offset and gain
• Trigger alerts when drift exceeds predefined thresholds
• Plan periodic re-calibration for metering-grade accuracy

Aging, Lifetime & Maintenance Planning

Over years of operation, mechanical stress, thermal cycling and magnetic aging shift the fluxgate’s characteristics. Aging manifests as slow drift in offset, gain and noise. The rate of drift depends on operating temperature, mechanical mounting and exposure to fault currents or transient overloads.

Design a maintenance strategy that includes periodic recalibration, self-test runs and inspection of mechanical mounting and busbar condition. Long-term logs of calibration and self-test data help determine whether drift remains within acceptable limits or if module replacement is warranted.

• Characterise drift over expected lifetime where possible
• Schedule recalibration or validation intervals
• Inspect mechanical mounting and thermal environment periodically
• Use logged data to decide when replacement is required

Vendor & Part Mapping for Fluxgate Closed-Loop Transducers

This section maps well-known fluxgate closed-loop current transducer families to typical use-cases such as DC-link metering, phase current sensing and EV traction inverters. Always cross-check latest datasheets for isolation ratings, bandwidth and accuracy before final selection.

LEM — High-Current Industrial & Traction

LEM offers a broad portfolio of fluxgate and closed-loop transducers for industrial drives, renewable energy and traction applications. Devices span tens to thousands of amperes with reinforced isolation and options for PCB, panel or busbar mounting.

• ITC / ITC-Family — Compact closed-loop transducers for ±50 A to ±200 A, voltage or current output versions, suited for DC-link and motor phase sensing in industrial drives.
• LTSR 15-NP / 25-NP / 50-NP — PCB-mount closed-loop transducers with primary conductor through aperture; typical for servo and robotics current feedback.
• LF 205-S / LF 310-S — High-current closed-loop transducers for traction and large inverters, supporting several hundred amperes with reinforced isolation.
• ART / DHAB series — Automotive-oriented current transducers targeting HEV/EV battery and traction applications.

Tamura — Industrial & Power Electronics

Tamura provides closed-loop transducers for general industrial inverters, UPS systems and renewable-energy converters, with a focus on robust performance and wide current ranges.

• L18P / L34P / L52P — PCB-mount closed-loop current transducers for ±15 A to ±50 A ranges, suitable for mid-power drives and SMPS applications.
• LF Series (e.g. LF-100K, LF-200K) — Panel-mount transducers for higher currents in industrial drives and power conversion.
• CurrentSense families for UPS / PV — Devices optimised for grid-tied inverters, UPS and power-quality monitoring.

VAC (Vacuumschmelze) — Precision Fluxgate Solutions

VAC offers precision fluxgate current sensors for metering, grid monitoring and traction drives with excellent accuracy, low drift and high isolation capability.

• T60404-F Series — Fluxgate-based current transducers for precision measurement tasks, e.g. DC metering and energy measurement.
• VACUUMSCHMELZE current sensor families — Dedicated closed-loop sensors for traction and renewable applications.
• High-precision fluxgate modules — Target applications where thermal drift and long-term stability are critical, such as calibration systems and lab equipment.

Other Industrial Vendors & Modules

Besides major fluxgate brands, several industrial suppliers provide closed-loop current transducers and modules aimed at specific sectors such as drives, UPS and EV charging. Cross-check mechanical form factor, isolation class and bandwidth with your target platform.

• Honeywell CSNX / CSNV Families — Closed-loop current sensors with high isolation and good linearity for industrial drives and converters.
• TE Connectivity / Measurement Specialties — Current transducer modules including fluxgate and Hall solutions for grid and industrial metering.
• Custom or module vendors — Various regional suppliers offer fluxgate-based current sensors tailored to local standards and busbar geometries.

Fluxgate IC + Core Solutions (Custom Transducer Design)

Some designs integrate fluxgate ICs with discrete cores and compensation windings to create custom transducers. These solutions are suitable where mechanical constraints, busbar geometry or specific isolation structures require a bespoke sensor.

• Fluxgate sensing ICs from specialist vendors — ICs providing excitation, demodulation and loop control, to be combined with custom cores.
• Custom core + winding houses — Partners capable of designing magnetic cores and windings that meet bespoke current ranges and isolation requirements.
• System integrators — Offer complete current-sensor modules integrated into power stacks, inverters or converter assemblies.

For shunt-based or Hall-effect current sensors within the same system, refer to the corresponding Current Sensing sub-pages rather than this fluxgate-focused mapping.

BOM & Procurement Notes for Fluxgate Closed-Loop Transducers

Fluxgate Closed-Loop Current Transducer — FAQs

1. When should I choose a fluxgate closed-loop current transducer instead of a shunt, Hall or Rogowski sensor?

Choose a fluxgate closed-loop transducer when you need isolated, sub-percent accuracy at tens to hundreds of amperes and good DC performance. Shunts excel at low-cost, low-voltage rails, Hall sensors at moderate accuracy, and Rogowski coils at high di/dt AC. For detailed trade-offs, map each rail to its safety, accuracy and isolation needs.

2. How does the zero-flux compensation loop in a fluxgate transducer actually work?

Fluxgate sensors drive a nonlinear core with an AC excitation and watch how the waveform changes when DC flux is present. A demodulator converts that imbalance into an error signal. The closed loop then drives a compensation current to force net flux back to zero, so measuring the compensation current is equivalent to measuring primary current.

3. How much headroom should I leave between my maximum primary current and the transducer’s rated range?

Leave headroom above your worst-case continuous and fault currents, not just the nominal rating. A common rule is 20–50 percent headroom for drives and chargers, more if fault currents last longer than a few microseconds. Too little margin forces the core into saturation early and stretches recovery time. Always check peak and fault tables, not only IFS.

4. What bandwidth or response time do I need for protection, control and metering loops?

Protection loops care about detecting big faults quickly, while control loops care about phase accuracy and linearity, and metering cares about low noise. Many designs use tens of kilohertz of bandwidth for control and protection, but only a few kilohertz for metering. Align the sensor’s bandwidth and filtering with your fastest loop and your ADC sampling strategy.

5. What limits di/dt and overload behaviour in a fluxgate closed-loop current transducer?

Di over dt is limited by the compensation amplifier, loop gain and magnetic dynamics, so very steep edges can outrun the loop and temporarily distort readings. Severe overloads push the core into saturation once compensation current hits its limit. Plan separate, very fast fault detectors, and treat the fluxgate reading as confirmation rather than the only shutdown trigger.

6. How should I interpret accuracy, linearity and drift figures in the datasheet?

Accuracy numbers combine offset, gain error, linearity and drift. Offset sets the minimum measurable current, gain error scales every reading, and linearity describes how error changes with current. Drift parameters tell you how all of this moves with temperature and time. Build a simple error budget, then see whether you need calibration hooks to meet your system target.

7. What are the key layout and mechanical integration rules for reliable fluxgate measurements?

Layout and mechanics decide whether the fluxgate ever reaches its datasheet accuracy. Keep the primary conductor centred in the aperture, route only the intended current path through the window, and avoid return currents nearby. On the secondary side, place burden and filters close to the pins and keep traces away from switching nodes and noisy grounds.

8. How do high dV/dt and common-mode noise in inverters affect fluxgate current sensing?

High dV over dt in inverters couples through parasitic capacitances and can inject common-mode disturbances into the fluxgate output. Good devices specify CMTI, but layout still matters. Keep high-dV over dt nodes away from secondary pins, give the sensor a solid analog ground island and test measurement stability under worst-case switching conditions, not only on a quiet bench.

9. Which isolation ratings and safety categories matter for drives, PV and EV traction systems?

Isolation ratings tell you which working voltage, pollution degree and over-voltage category the transducer can safely support. Basic insulation may be fine for internal signaling, while reinforced insulation is often needed for grid-tied and traction systems. Match the sensor’s insulation class and creepage and clearance recommendations to your system standard and expected lifetime stress profile.

10. What calibration and self-test strategies are recommended for fluxgate transducers?

A minimum scheme uses zero-current offset calibration at start-up and perhaps a single gain calibration against a known reference current. More demanding systems schedule periodic offset checks, store temperature with every calibration result and compare them against drift limits. If the sensor offers built-in self-test, integrate it into maintenance windows and log failures as health indicators.

11. How do aging and long-term drift affect fluxgate current sensors over the product lifetime?

Aging slowly shifts offset, gain and noise as the core, windings and analog circuitry experience thermal cycling and magnetic stress. Performance may stay inside data-sheet limits for years, but precision metering or safety-critical loops should still plan periodic verification. Use long-term logs of calibration and self-test results to decide whether you can recalibrate or need replacement.

12. Which BOM fields should I share with suppliers to get a realistic fluxgate current sensor proposal?

Suppliers respond much faster when your RFQ includes primary current ranges, accuracy and drift targets, isolation and working voltage class, mechanical constraints such as busbar size and window geometry, interface type and bandwidth expectations, and environment and lifetime details. Put those fields into your BOM or submit-BOM form so proposals arrive close to what your design actually needs.