New MLX91218 and MLX91219 3.3V/5V sensors with high-accuracy simplify inverter/converter control and battery management

Melexis has revealed next-generation current sensors, MLX91219 and  MLX91218 for automotive power-conversion applications which helps in delivering increased resolution, optional 3.3V or 5V operation, and integrated over-current detection circuitry. The MLX91219 is a conventional hall current sensor with a ferromagnetic C-core through which currents can be measured in the ranges of 200A to beyond 2000A while MLX91218 is an IMC-Hall current sensor with a flexible U-shield for crosstalk immunity and it can measure current from 200A to 2000A. Both the sensors integrate over-current detection (OCD) circuitry typically implemented off-chip using an external window comparator which further simplify system design, save board space, and reduce the bill of materials.

These sensors benefit from an increased signal to noise ratio (SNR) and features high linearity, within ±0.3% full scale. These AEC-Q100 automotive-qualified sensors deliver enhanced accuracy for managing high speed applications such as motor control, inverters and converters, but also redundant monitoring of battery-management systems (BMS). Moreover, minimal thermal drift, maintaining electrical offset within +/-5mV and sensitivity within +/-1% ensures accuracy over a wide temperature range and the over-current threshold is set internally during initial product configuration. The SOIC8 packaged products have an additional pin that allows setting the threshold voltage with increased accuracy using an external voltage divider. Two indicator pins show the overcurrent status in relation to internal and external thresholds, with 2us and 10us response times respectively.

Both sensor types provide a selectable analog output that allows the choice of a fixed output or ratiometric output that scales with the supply voltage. With 400kHz bandwidth and fast response time, they are suitable for circuits designed to operate at high switching speeds and fundamental frequencies to minimize phase delay in the control loop. In addition, the future MLX91218 incorporates Melexis’ patented IMC integrated magnetic concentrator to optimize magnetic field shaping, which allows compact, lightweight shielding. With the option of either 3.3V or 5V operating voltage, designers can use these sensors directly in circuits containing new 3.3V low-voltage microcontrollers or with legacy 5V devices.

Features and Benefits of sensors

• End-of-line programmable sensor
• Factory selected 5V or 3.3V supply
• Measurement range from ±12 to ±500mT
• High speed AC and DC current sensing
  • 400kHz bandwidth
  • 2μs response time
• High linearity down to ±0.5% full scale
• Low noise
• AEC-Q100 – Grade 0 Automotive Qualification
• Very low thermal drift for wide range
  • Offset drift (<5mV) c
  • Sensitivity drift (<1%)
• Fast dual overcurrent detection
  • Internal threshold
  • External threshold (Only SOIC8)
• RoHS compliant

Applications of MLX91219

• High Voltage Traction Motor Inverter
• 48V Boost Recuperation Inverter
• DCDC Converter
• Smart Battery Junction Boxes or BDU
• Smart Fuse Overcurrent Detection
• Battery Management System (BMS)

Availability

The single inline (SIP) 4-pin package for MLX91219 is now available while the  MLX91218 and the small-outline SOIC8 package for MLX91219 will be available soon.