currentranger's Introduction

CurrentRanger

Precision auto-ranging current meter (ammeter)

Please see the full guide and latest updates posted here.

Quick Highlights

Here are some of the features of this instrument which sets it apart:

Low noise zero-offset with 3-ranges (1mV output per nA/µA/mA)
Low input burden voltage, high precision & bandwidth analog outputs
Increased flexibility and usability with several input and output terminal options
Auto-ranging capable
Use standalone with a small OLED display or with a multimeter/oscilloscope
Ultra fast range switching between any ranges (even nA to mA) without any glitching/bouncing of a mechanical switch
Low Pass Filter mode – very useful to capture low noise signals on oscilloscopes
Unidirectional mode – most used mode in measuring DC currents ranging from [0, 3.3A]
Bidirectional mode – split supply biasing allows AC currents measurement ranging from [-1.65A, 1.65A]
LiPo battery powered – long life and extended measurement range
Auto-power-off
Full digital control for power & range switching via touch pads
OLED display option to read output with usable precision
Datalogging possible via Bluetooth serial module
SAMD21 Cortex M0+ powered, change firmware to your needs
Optional buzzer for audible feedback
Current ranges output:
- 0-3300 nA/µA/mA (Unidirectional mode)
- +/- 0-1650 nA/µA/mA (Bidirectional mode)
- Burden voltage:
- 17µV/mA
- 10µV/µA
- 10µV/nA
Output offset voltage¹: typically <10µV, max 50µV
Maximum input voltage differential (see Safety): 33mV
Accuracy:
- +/-0.05% (µA, nA ranges)
- +/-0.1% (mA range)
Highest resolution (nA range):
- 100pA (3.5digit meter)
- 10pA (4.5 digit meter)
- 1pA (5.5 digit meter)
Cascaded MAX4239 amplifiers with 100x output gain
- Bandwidth: >300KHz (-3dB)