LowPowerLab CurrentRanger R3 Current Sense Amplifier

The CurrentRanger is a nano-ampere current amplifier with automatic range selection, uni/bi-directional mode, Bluetooth data logger options and more.

It is an affordable current meter with an extremely low burden voltage that enables the detection of fast current transients with high measurement accuracy.

Highlights

• Low-noise amplifier with zero offset and three ranges (1mV per nA/µA/mA)
• Ultra-low burden voltage, high accuracy and bandwidth
• Ultra-fast manual or automatic range switching (Auto-Ranging) between any ranges (also nA to mA) without glitching/bouncing of a mechanical switch
• Fully digital control of range switching via touchpads, buzzer for acoustic feedback
• Connection to a multimeter or oscilloscope as well as standalone operation with optional OLED display possible
• Wireless data logging via optional Bluetooth module possible
• Low pass filter mode for low noise signal acquisition on oscilloscope
• Switchable unidirectional or bidirectional mode: Measurement of DC currents in the range of 0 .. +3.3A or AC current measurement in the range of -1.65A ... +1.65A.
• Rechargeable and long battery life thanks to LiPo battery and auto power-off
• SAMD21 Cortex M0+ microcontroller with customizable open source firmware

Use information

Please read the manual first!

It is important to understand how to use the CurrentRanger correctly, otherwise it may be damaged. To keep cost low, there is no galvanic isolation between input, output and USB port or other pin headers. Ground loops and current paths from the input to the output or to the USB port are to be avoided at all costs.

Box Contents

• CurrentRanger board
• Low profile sockets for 4mm banana plugs (4 pcs)
• Input terminal for simple wire connection (separate, can be soldered)
• Buzzer for acoustic feedback (separate, can be soldered)
• 3D-printed PLA case and mounting screws
• 0.96" OLED display (optional)
• LiPo battery with JST connector (optional)

Technical data

• Current ranges:
  • 0 .. 3300 nA/µA/mA (unidirectional mode)
  • +/- 0 .. 1650 nA/µA/mA (Bidirectional mode)
• Burden voltage:
  • 17µV/mA
  • 10µV/µA
  • 10µV/nA
• Output offset voltage*: typically <10µV, max. 50µV
• Maximum allowed input voltage difference: 33mV
• Accuracy:
  • +/-0.05% (µA, nA ranges)
  • +/-0.1% (mA range)
• Highest resolution (nA range):
  • 100pA (3.5-digit number)
  • 10pA (4.5-digit number)
  • 1pA (5.5-digit number)
• Bandwidth: >300KHz (-3dB)      

*) Note: It may take a few minutes for the offset to reach its lowest value (time to recover).