LabJack U3
The LabJack U3 is a low-cost USB DAQ with up to 16 flexible 12-bit analog inputs, two 10-bit analog outputs, two counters and two timers. The U3-LV has 0 to 2.44 V inputs and the U3-HV adds four ±10 V inputs. LabJack now recommends the T4 for new designs.
Specifications
| Analog inputs | 16up to 16 via flexible I/O lines configured as analog; U3-HV has 4 high-voltage inputs (AIN0 to AIN3) |
| Resolution | 12-bitfull resolution in stream mode only up to 2,500 S/s |
| Max sample rate | 50 kS/sstream mode, aggregate across channels |
| Input ranges | U3-LV: 0 to 2.44 V SE, ±2.44 V DIFF, 0 to 3.6 V special; U3-HV adds ±10 V (and -10 to +20 V special) on AIN0 to AIN3 |
| Input modes | single-ended, differential |
| Analog outputs | 2 × 10-bit |
| Digital I/O | 16 |
| Counters | 2 |
| Isolation | No |
| Interfaces | USB |
| List price | $160labjack.com, Oct 2026 (U3-LV and U3-HV) |
Vendor driver by OS
| Driver | none |
| Windows | Yes |
| macOS | Yes |
| Linux | Yes |
Vendor software
| LJControlPanel | WindowsFree. Configuration and test; requires the UD driver |
| LJLogUD | WindowsFree. Logging; requires the UD driver |
| LJStreamUD | WindowsFree. Stream-mode logging; requires the UD driver |
U3-LV and U3-HV
Both variants list at $160 at the time of writing. The U3-LV’s inputs are low-voltage: 0 to 2.44 V single-ended, ±2.44 V differential, or 0 to 3.6 V in a special range. The U3-HV replaces four of those with high-voltage inputs that read ±10 V, or -10 to +20 V in their special range. Flexible I/O lines switch between analog input and digital I/O, so the analog channel count depends on how you configure them. Resolution is 12 bits and the stream rate is 50 kS/s aggregate, but full-resolution streaming is limited to 2,500 S/s, and faster rates trade away effective bits. The two analog outputs are 10-bit and filtered from PWM, with a 16 Hz cutoff. LabJack’s comparison page lists the U3 as active, with end of life expected around 2030.
UD driver on Windows, Exodriver on Mac and Linux
The U3 belongs to LabJack’s second-generation UD family. On Windows, the UD driver installs with LJControlPanel and LabJack’s UD logging apps. LabJack’s U3 datasheet says the UD driver, LJControlPanel and LJSelfUpgrade are not available on macOS or Linux. There it points to the Exodriver, a low-level native USB driver, with LabJackPython running on top of it. LJM and Kipling, LabJack’s current cross-platform software, support only T-series and Digit devices.
Replacing the U3 or keeping it
DAQAtlas, which is in development, talks to LabJack hardware through LJM, so it supports the T4, T7 and T8 but not the U3, U6 or UE9. For new hardware with Mac or Linux logging, the LabJack T4 is LabJack’s recommended replacement, with USB and Ethernet, Lua scripting and LJM support. If you keep the U3, Python data acquisition covers scripting options.
Questions
Does the LabJack U3 work on macOS?
Only at a low level. LabJack’s UD driver and Windows apps are not available on macOS; you install the Exodriver and program the U3 directly or through LabJackPython.
Does DAQAtlas support the LabJack U3?
No. DAQAtlas, which is in development, uses LJM for LabJack devices, and the U3 uses the older UD driver and Exodriver. The T4, T7 and T8 are supported.
What is the difference between the U3-LV and U3-HV?
The U3-HV replaces four low-voltage inputs (AIN0 to AIN3) with high-voltage inputs that read ±10 V. Both list at the same price.
Specifications and prices are taken from the vendor’s published pages at the time of writing and can change. Check the vendor before you buy. Sources: 1 · 2 · 3 · 4 · 5 · 6 · 7