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Allegro MicroSystems CTD431-65DC
- Part No.:
- CTD431-65DC
- Manufacturer:
- Allegro MicroSystems
- Category:
- Sensor Evaluation Boards
- Package:
- Datasheet:
-
CTD431-65DC.pdf
- Description:
- EVAL BOARD FOR CT431
- Quantity:
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- Shipping:
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Product details
Overview
CTD431-65DC from Allegro MicroSystems is a high-bandwidth, ultra-low-noise integrated contact current sensor using XtremeSense™ TMR technology for precision DC current measurement up to 65 A. It delivers linear analog voltage output with ≤±1.0% full-scale total error over –40°C to 125°C, 1 MHz bandwidth, and ~300 ns response time, and is used in battery management systems and motor control for accurate real-time current monitoring.
For engineers reviewing the CTD431-65DC datasheet, CTD431-65DC pinout, CTD431-65DC application, or CTD431-65DC equivalent, this page provides verified specifications, functional context, package details, application-specific implementation guidance, and validated alternative options for industrial and automotive current sensing designs requiring reinforced isolation, low noise, and AEC-Q100 Grade 1 compliance.
Technical Context
The CTD431-65DC implements a monolithic TMR-based sensing element with an integrated current-carrying conductor (CCC) rated for 65 A DC, delivering analog output referenced to VREF (0.65 V for unipolar mode). Its architecture includes on-chip overcurrent detection (OCD) with hysteresis, active-low open-drain FLT output, and internal filter resistor (15 kΩ) for external RC noise suppression.
It operates from 3.0–3.6 V supply, consumes ~6.0 mA, achieves –54 dB common-mode field rejection, and meets UL/IEC 62368-1 and UL1577 with 5 kVRMS dielectric withstand voltage and 550 VRMS reinforced working voltage - enabling safe integration into isolated power stages without external galvanic barriers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Current Range | 0 to 65 A DC - supports unipolar high-current battery feed and DC bus monitoring without polarity reversal. |
| Total Output Error | ≤ ±1.0% FS over –40°C to 125°C - ensures stable accuracy across automotive and industrial thermal environments without recalibration. |
| Bandwidth | 1 MHz - enables faithful capture of fast-switching transients in SiC/GaN inverter applications. |
| Response Time | ~300 ns - allows real-time fault detection and closed-loop current control in high-speed motor drives. |
| Noise Density | 11.5 mARMS @ 100 kHz - supports high-resolution current resolution in noise-sensitive BMS cell balancing circuits. |
| Isolation Rating | 5 kVRMS dielectric withstand, 550 VRMS reinforced working voltage - satisfies safety-critical isolation requirements per IEC 62368-1. |
| Supply Voltage | 3.0–3.6 V - compatible with standard 3.3 V logic domains and low-power microcontrollers. |
Pinout & Package
The CTD431-65DC is housed in a green, RoHS-compliant 16-lead SOIC wide (SOICW) package measuring 10.21 mm × 10.31 mm × 2.54 mm, with creepage and clearance ≥7.8 mm and 110 µm internal isolation distance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 | IP+ | Primary conductor input terminal - carries up to 65 A DC; must be routed with low-inductance PCB traces. |
| 5, 6, 7, 8 | IP− | Primary conductor return terminal - completes CCC path; symmetric layout required for field cancellation. |
| 9 | VREF | Stable 0.65 V reference output - used as ADC reference or offset calibration point; requires ≤10 kΩ load. |
| 10 | GND | Analog ground reference - must be connected to clean system ground plane adjacent to VCC bypass capacitor. |
| 11 | FLT | Active-low open-drain fault signal - asserts when OCD or UVLO occurs; requires external pull-up to VCC. |
| 12 | FILTER | RC filter node - connects external capacitor to set cutoff frequency; unused pins must remain floating. |
| 13 | OUT | Analog output voltage (0.65–2.65 V) proportional to sensed current - directly interfaces with 12-bit+ SAR ADCs. |
| 14, 16 | N/C | No-connect terminals - must be left unconnected; no internal bonding or function. |
| 15 | VCC | 3.0–3.6 V supply input - requires 1.0 µF ceramic bypass capacitor placed within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| XtremeSense™ TMR Sensing | Enables <1% total error and 11.5 mARMS noise at 100 kHz - critical for high-fidelity battery pack SoC estimation. |
| Integrated CCC (65 A) | Eliminates external shunt and associated power loss, thermal drift, and PCB space - reduces bill-of-materials in EV traction inverters. |
| Reinforced Isolation (550 VRMS) | Meets IEC 62368-1 reinforced insulation requirements - enables direct connection to high-voltage DC buses without optocouplers or isolators. |
| On-Chip OCD with Hysteresis | Detects overcurrent at 1.1× range (71.5 A) with 0.2× hysteresis (13 A) - prevents nuisance tripping during transient surges in motor startup. |
| AEC-Q100 Grade 1 | Qualified for automotive ambient temperatures (–40°C to +125°C) - suitable for under-hood and battery-pack mounted current sensing. |
Applications
| Battery Management Systems | Motor Control |
|---|---|
Use Scenario: Real-time monitoring of pack-level charge/discharge current in 400 V–800 V EV battery systems. IC Role / Device Role / Timing Role: Primary current sensor providing analog feedback to BMS MCU for state-of-charge (SoC), state-of-health (SoH), and thermal runaway prevention. Use Value: ≤±1.0% FS error and 300 ns response enable precise Coulomb counting and rapid fault shutdown before cell damage occurs. | Use Scenario: Phase current sensing in three-phase PMSM or BLDC motor drives for field-oriented control (FOC). IC Role / Device Role / Timing Role: High-bandwidth current feedback device interfacing with PWM-controlled gate drivers and ADCs in real-time control loops. Use Value: 1 MHz bandwidth and low noise preserve current waveform fidelity during high-frequency switching, improving torque ripple and efficiency. |
| Solar Inverters | Industrial UPS |
Use Scenario: DC-side string current monitoring and AC-side output current protection in grid-tied photovoltaic inverters. IC Role / Device Role / Timing Role: Isolated current transducer for both MPPT tracking and overcurrent trip functions in dual-conversion topologies. Use Value: Reinforced isolation rating and 5 kVRMS surge withstand allow direct integration into high-voltage DC input stages without auxiliary isolation components. | Use Scenario: Input and output current monitoring in modular uninterruptible power supplies for datacenter backup systems. IC Role / Device Role / Timing Role: Dual-role sensor supporting both load current regulation and short-circuit protection via FLT pin assertion. Use Value: Integrated OCD and fast FLT response (<250 ns) enable sub-microsecond fault detection, meeting IEC 62040-1 short-circuit coordination requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current sensing applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CT433-65DR | Successor device with identical 0–65 A range, same SOICW package, but improved lifetime drift (±1.5% FS vs. ±2.3% FS) and updated AEC-Q100 qualification. | Designed for new designs; CTD431-65DC is Not for New Design per Allegro's March 2025 status update. | Select CT433-65DR for all new projects requiring long-term supply continuity and enhanced stability. |
| ACS724LLCTR-65AB-T | 65 A bipolar Hall-effect sensor; lower bandwidth (80 kHz), higher noise (20 mARMS), and ±1.5% total error - lacks reinforced isolation certification. | Suitable only where basic isolation suffices and cost sensitivity outweighs accuracy or safety certification needs. | Use ACS724LLCTR-65AB-T only in non-safety-critical industrial controls with relaxed accuracy and isolation requirements. |
Compared with CTD431-65DC, CT433-65DR offers superior long-term stability and design support continuity, while ACS724LLCTR-65AB-T trades isolation robustness and precision for lower cost in less demanding applications - making CT433-65DR the recommended upgrade path for new designs.
Availability
CTD431-65DC is available at Aetrix Electronics and suitable for battery management systems, motor control, solar inverters, and industrial UPS requiring stable component supply despite its Not for New Design status.
Supply support for CTD431-65DC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensors and power ICs, specializing in motion control, energy-efficient power conversion, and precision current sensing.
The CT431 product line delivers isolated, high-accuracy current sensing using proprietary XtremeSense™ TMR technology for automotive, industrial, and renewable energy applications demanding reliability, low noise, and safety certification.
FAQ
What is the maximum continuous current rating for CTD431-65DC?
The CTD431-65DC supports a maximum continuous primary current of 65 A DC in unipolar configuration. Its integrated current-carrying conductor (CCC) is rated for 70 A absolute maximum under TA = 25°C per absolute ratings, but sustained operation at 65 A is validated across –40°C to 125°C with ≤±1.0% total error. Derating may be required above 100°C ambient.
Does CTD431-65DC require external filtering components?
CTD431-65DC includes an internal 15 kΩ filter resistor (RFILTER) on the FILTER pin; an external capacitor must be added to set the desired cutoff frequency. If noise performance is not critical, the FILTER pin may be left unconnected. No external shunt, amplifier, or isolation components are needed due to its fully integrated architecture.
What is the meaning of "Not for New Design" for CTD431-65DC?
"Not for New Design" indicates that Allegro has discontinued marketing CTD431-65DC for new product development as of March 28, 2025. While still in production for existing customer programs, it is not recommended for new designs due to probable near-term obsolescence. CTD431-65DC remains supported for legacy production, but CT433-65DR is the designated replacement.
How does the FLT pin operate in CTD431-65DC?
The FLT pin on CTD431-65DC is an active-low, open-drain output that asserts low during overcurrent detection (OCD) or undervoltage lockout (UVLO). It triggers at 1.1× full-scale current (71.5 A) with 13 A hysteresis and responds in <250 ns. An external pull-up resistor (typically 10–100 kΩ to VCC) is required for proper logic-level signaling to the host MCU.
Is CTD431-65DC certified for reinforced isolation?
Yes, CTD431-65DC is certified for reinforced isolation per UL 62368-1 and UL 1577, with a rated dielectric withstand voltage of 5 kVRMS and a reinforced working voltage of 550 VRMS. This enables safe use in high-voltage systems such as EV battery packs and solar inverters without additional isolation barriers.
CTD431-65DC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- XtremeSense™ Crocus Technology
- Packaging:
- Bulk
- Product Status:
- Active
- Sensor Type:
- Current Sensor
- Sensing Range:
- 65A
- Interface:
- Analog
- Sensitivity:
- 30.8mV/A
- Voltage - Supply:
- 3V ~ 3.6V
- Embedded:
- No
- Contents:
- Board(s)
- Utilized IC / Part:
- CT431
CTD431-65DC FAQ
1.How can I place an order for CTD431-65DC through Aetrix?
Please submit a Request for Quotation (RFQ) for CTD431-65DC on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for CTD431-65DC reliable?
The price and inventory of CTD431-65DC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CTD431-65DC is usually 5 days.
3.What payment methods are accepted for CTD431-65DC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CTD431-65DC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CTD431-65DC?
CTD431-65DC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CTD431-65DC order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for CTD431-65DC?
For technical support, including CTD431-65DC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CTD431-65DC requirements.
6.How does Aetrix verify that CTD431-65DC is sourced from the original manufacturer or authorized distributors?
All CTD431-65DC products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that CTD431-65DC meets industry standards.
7.What is the process for return or replacement of CTD431-65DC?
All CTD431-65DC units undergo pre-shipment inspection (PSI). If there is an issue with CTD431-65DC, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The CTD431-65DC part is unused and in its original packaging.
Return procedure for CTD431-65DC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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