This item is made to order, and may take 3-4 business days to ship. Please get in touch if you need it urgently, and we'll see what we can do!
An Open Hardware, low-noise, oscilloscope power rail probe. It allows you to measure millivolt-level ripple on a power rail up to 25V, with 1GHz bandwidth, using a normal oscilloscope. Commercial versions of this product cost upwards of £4,850!
The probe accepts a connection from a power rail under test, via a 50-ohm cable. AC is passed, and an adjustable offset is applied to the DC voltage. Your oscilloscope sees 0V DC, allowing power supply ripple and transients to be viewed in high resolution.
New v2.0 model available with SMA connectors and improved frequency response.
- Open Hardware, made in the UK. Schematics and design files are freely available.
- Max voltage offset ±25.9V
- Input impedance 50kΩ (0 - 30kHz) / 50Ω (30kHz - 2GHz)
- Nominal AC signal attenuation of 1:1.07 (approx. -0.31 dB)
- DC step relative error <0.5%
- Frequency response (S12) flat
-
- ...within 1dB 265kHz - 500MHz
- ...within 2dB 265kHz - 810MHz
- ...within 3dB 265kHz - 1100MHz
- Frequency response fully characterised to 2GHz, S-parameters supplied
- Noise <190 µVrms over full measurement bandwidth (0Hz to 1GHz)
- Active signal range ±1.75V
- Precision SMA female test connectors
- Indication of over-range signal (above or below offset setting)
- High-precision Nidec M-1305 5-turn potentiometer for accurate offset adjustment
- Battery powered to minimise noise
- Li-Ion 18650 batteries rechargeable via USB-C connector
- 9V+ USB-PD supply required - most laptop power supplies are compatible - or alternatively 12V DC barrel jack
- Version 2.0
The user guide with typical S-parameters is available here.
The probe should be connected to an oscilloscope set to 50-ohm input impedance, and works best with inputs <10-ohm impedance.
Frequency response
The probe's frequency response is flat within 1dB between approximately 265kHz and 500MHz, and flat within 3dB to 1.1GHz.
What's included?
Assembled probe
- 1x finished power rail probe, ready to use.
No cables are included. You will need to supply your own USB-C power cable and USB-C power supply capable of 9V USB-C PD (eg, a laptop power supply). Most USB-C power supplies advertising 20W or higher are suitable.
Alternatively, you can tick the box to include a USB-C cable and compatible UK power supply. International customers will need to use an appropriate international adapter.
Assembled probe + BNC cable kit
- 1x finished power rail probe, ready to use.
- 2x 1 metre coaxial cables (BNC male - BNC male)
- 2x SMA male - BNC female adapters
PCB and enclosure option
If you select this option, you'll receive
- an unpopulated PCB
- an aluminium enclosure
- machined front and back panels + bolts.
You'll need to purchase the components and assemble the board yourself (see GitHub for a BOM & schematic).
This product must be shipped via DHL, due to the internal batteries.