uCurrent Gold: Burden Voltage Eliminator

Summary

The uCurrent™ provides a solution for the problem of burden voltage on a multimeter. This little-known problem can be a real big issue, even on a "precision" 0.05% multimeter. It also turns your multimeter into a powerful and precise nanoamp level measurement tool.

Thousands are in use all around the world, and it has quickly become the industry standard low-cost tool for low power current measurement in modern low power microcontroller based digital electronics.

The µCurrent™ GOLD is the latest design with greatly improved specs over the original. Improvements have been made in basic accuracy, bandwidth (now you can measure fast changing "sleep" modes), current handling, and an added shorting mode to ensure uninterrupted power to your device under test while changing ranges. The µCurrent can rival 5 1/2 digit multimeters in accuracy, it is truly a precision instrument.

Specifications - µCurrent™ GOLD:

3 Current ranges:

± 0-1250mA (20µV / mA burden voltage typical) * switch contact resistance plays a role here. 10µV due to the shunt resistor.
± 0-1250µA (10µV / uA burden voltage)
± 0-1250nA (10µV / nA burden voltage)
(NOTE: Higher currents are available by increasing the battery voltage, to a maximum of 5.5V, which would give ±2250mA/2250µA/2250nA maximum)

Output Voltage Units:

1mV/mA
1mV/µA
1mV/nA

Resolution (nA range): 100pA (3.5digit meter), 10pA (4.5 digit meter), 1pA (5.5 digit meter)

Accuracy (typical): <±0.05% on µA and nA ranges, <±0.1% on mA range.

Output Offset Voltage: <50µV (essentially insignificant on 4.5 digit meter)

Bandwidth: >300KHz (-3dB)

Temperature Drift: <10ppm / degC (µA/nA), <15ppm / degC (mA)

Noise: < -90dBV

THD: < -60dB

Battery: CR2032 Lithium coin cell (optional 3 x AAA's)

Battery Life: >50 hours (battery good LED ensures accurate measurement when LED is on). 2.65V cutout voltage.

Specifications

Manufacturer	Analog Devices Inc./Maxim Integrated
Category	Sensor Solutions
Sub-Category	Current Sensing
Eval Board	Board not Stocked
Voltage In	2.7 ~ 5.5 V
Sensing Method	Resistive Current Sensor
Current Sensing Max	1.25 uA 1.25 mA 1.25 A
Features	Bad Battery Detection
Quiescent Current [Maximum]	- Not Given
Quiescent Current [Typical]	- Not Given
Component Count + Extras	27 + 4
Design Author	Dave Jones
Main I.C. Base Part	MAX4239
Date Created By Author
Date Added To Library	2018-11