MCU-758 ACS758LCB-050B 50A Bidirectional Hall-Effect Current Sensor Module

 Specifications

• Sensor IC: Allegro ACS758LCB-050B-PFF-T
• Current Sensing Range: $\pm50\text{A}$ (Bidirectional AC / DC)
• Sensitivity: $40\text{ mV/A}$ (at 5.0V VCC supply)
• Zero-Current Voltage Output: $\text{VCC} / 2$ (Nominally 2.5V at 5.0V VCC)
• Supply Voltage (VCC): 3.0V to 5.5V DC (5.0V recommended for maximum dynamic range)
• Primary Conductor Resistance: $100\ \mu\Omega$ ($0.1\text{ m}\Omega$) typical for minimal power loss
• Galvanic Isolation Voltage: 1000V RMS dielectric isolation rating
• Bandwidth: 120 kHz typical
• Output Type: Analog Voltage (Linear output proportional to applied current)
• Operating Temperature: -40°C to +150°C (Core IC rating)

Applications

• Solar Power Systems: High-current solar inverter monitoring and MPPT charge controller tracking.
• Electric Vehicles & Robotics: High-power BLDC and brushed DC motor current profiling and over-current protection.
• Industrial Automation: Machine load detection, pump current diagnostics, and power supply metering.
• Battery Management Systems (BMS): Bidirectional state-of-charge (SoC) Coulomb counting and charge/discharge rate logging.

Unlock New Capabilities

• Past Projects: If you've mastered basic power monitoring using the small 20A ACS712 sensors...
• Feature Upgrade: This MCU-758 ACS758 module unlocks heavy-lifting! Move from desktop hobby electronics to monitoring house-scale solar rigs and electric go-kart motors with professional isolation.
• Effort/Requirements: Intermediate. You will need a 5V microcontroller (like an Arduino Uno), high-gauge AWG wire for the load terminals, and a solid understanding of how to read and scale analog inputs (ADC).

Package included:

• 1 x MCU-758 ACS758LCB-050B 50A Bidirectional Hall-Effect Current Sensor Module

Frequently Asked Questions (FAQ)

• What is the maximum current this MCU-758 module can measure?
  It can measure up to ±50A safely.
• Does the ACS758LCB-050B measure AC or DC current?
  It measures both AC and DC bidirectional current.
• What is the resting output voltage when no current is flowing?
  The output rests at exactly half of the supply voltage (VCC / 2). If VCC is 5V, output is 2.5V.
• What is the sensitivity of the 50A variant?
  The ACS758LCB-050B has a sensitivity of approximately 40 mV per Ampere.
• Can I use this with a 3.3V microcontroller like an ESP32 or Raspberry Pi Pico?
  Yes, you can power it with 3.3V, but the sensitivity and resting voltage will scale proportionally. Alternatively, use a voltage divider on the output if powering at 5V.
• Is the output digital (I2C/SPI) or analog?
  The output is a purely analog voltage signal.
• What is the difference between the OU1 and OU2 pins?
  OU1 usually has a built-in RC filter capacitor on the PCB for smoother readings, while OU2 provides the raw, fast-response output directly from the IC.
• How does it protect my microcontroller from 50A spikes?
  The sensor relies on the Hall-effect. There is no physical electrical connection between the high-current IP+ / IP- path and your microcontroller pins, providing galvanic isolation.
• What is the accepted operating voltage (VCC) of the module?
  The module strictly operates between 3.3V and 5V DC.
• Can I connect this directly to an AC mains power line?
  While the IC provides galvanic isolation, working with AC mains requires strict safety enclosures, fused setups, and extreme caution. Ensure your PCB mounting is safely isolated.
• How do I calibrate the ACS758 sensor in software?
  Read the analog value multiple times at exactly 0 Amps, find the average, and set that baseline as your "Zero Current" offset in your code before calculating the mV/A slope.
• Why does my Arduino analog reading fluctuate randomly?
  Hall-effect sensors are sensitive to stray magnetic fields and power supply noise. Ensure you are using a stable VCC, apply software averaging, and use the filtered OU1 pin.