Siglent SPD3303 Series
Three trusted 3-channel linear bench supplies — the value SPD3303C, the colour-display SPD3303X-E and the precision SPD3303X. Two 0–32 V/3.2 A channels plus a fixed 2.5/3.3/5 V logic rail, 220 W, with series and parallel modes.
A proven three-rail bench supply
The SPD3303 has been a workshop and lab staple for years, and for good reason. You get two fully adjustable 0–32 V / 3.2 A channels for your main rails, plus a fixed channel you can set to 2.5, 3.3 or 5 V — a ready-made logic supply for digital boards. All three outputs are isolated and can be switched on or off independently or together.
It's a linear design, so ripple and noise stay low (≤ 1 mVrms) — well suited to analog, audio, RF and teaching work. Combine the two main channels in series for up to 60 V or in parallel for up to 6.4 A when a project needs more. Pick the model by the display, resolution and connectivity you need — the output is the same across all three.
Made for everyday bench work
Timing output & waveform display
Programmable panel timing lets you run automated voltage/current steps. On the SPD3303X the 4.3" colour display also charts live voltage and current per channel, so you can watch how a load behaves over time.
Series / parallel / independent
Run the two main channels separately, combine them in series for up to 60 V, or in parallel for up to 6.4 A — one instrument that adapts to higher-voltage or higher-current jobs.
5 memory presets
Save and recall up to 5 sets of voltage/current settings for repeatable test setups.
Front-panel key lock
Lock the controls to prevent accidental changes during a test or in a teaching lab.
SCPI + EasyPower
Automate from a PC with the SCPI command set and the free EasyPower software (USB on all models; LAN on X / X-E).
Rear panel — connections & power
The output binding posts are on the front; the rear carries the communication and mains connections (SPD3303X / X-E shown — the SPD3303C uses USB only and has no LAN port).
Network control via SCPI on the SPD3303X and SPD3303X-E (not fitted on the SPD3303C).
PC connection for the SCPI command set and the free EasyPower software — standard on all three models.
An intelligent fan that ramps only as needed, keeping bench noise down.
Manual selector for 100 / 120 / 220 / 230 V so the unit runs on any regional grid.
IEC mains socket with an integrated, voltage-dependent fuse holder.
All three channels terminate in colour-coded binding posts on the front panel for easy lead access.
Three models — same output, different display & resolution
Every model delivers the same 3-channel, 220 W output. Choose by display type, resolution and connectivity.
- LED (4-digit V / 3-digit I)
- USB Device
- 2× 0–32 V/3.2 A + fixed 2.5/3.3/5 V · 220 W
The value choice for the bench, workshop and education — full 3-channel output without a display upgrade.
- 4.3" TFT (4-digit V / 3-digit I)
- USB Device + LAN
- 2× 0–32 V/3.2 A + fixed 2.5/3.3/5 V · 220 W
Adds a clear colour display and LAN networking — ideal for a connected bench or shared lab.
- 4.3" TFT + waveform (5-digit V / 4-digit I)
- USB Device + LAN
- 2× 0–32 V/3.2 A + fixed 2.5/3.3/5 V · 220 W
The precision model — 10× finer 1 mV/1 mA resolution, higher accuracy and a real-time waveform display for R&D.
Which SPD3303 is right for you?
The output is identical on all three — the choice comes down to three things: the display, how finely you can set and read voltage/current, and whether you need LAN networking.
| SPD3303C | SPD3303X-E | SPD3303X | |
|---|---|---|---|
| Display | LED | 4.3" colour TFT | 4.3" colour TFT + waveform |
| Resolution | 10 mV / 10 mA | 10 mV / 10 mA | 1 mV / 1 mA |
| Voltage accuracy | ±(0.5% + 3 dig) | ±(0.5% + 2 dig) | ±(0.03% + 10 mV) |
| Interfaces | USB | USB + LAN | USB + LAN |
| Best for | Value bench & education | Connected / shared lab | Precision R&D |
| Price | €249 | €380 | €509 |
| Shared | 3 channels (2× 0–32 V/3.2 A + fixed 2.5/3.3/5 V) · 220 W · series/parallel · ≤ 1 mVrms ripple · < 50 µs recovery · 5 memories · key lock | ||
Full specifications
The table shows where the three models differ; everything below it is shared across the whole series.
| Specification | SPD3303C | SPD3303X-E | SPD3303X |
|---|---|---|---|
| Display | LED (4-digit V / 3-digit I) | 4.3" colour TFT (4-digit V / 3-digit I) | 4.3" colour TFT + waveform (5-digit V / 4-digit I) |
| Setting resolution | 10 mV / 10 mA | 10 mV / 10 mA | 1 mV / 1 mA |
| Voltage programming & readback | ± (0.5% + 3 digits) | ± (0.5% + 2 digits) | ± (0.03% of reading + 10 mV) |
| Current programming & readback | ± (0.5% + 3 digits) | ± (0.5% + 2 digits) | ± (0.3% of reading + 10 mA) |
| Interfaces | USB Device | USB Device + LAN | USB Device + LAN |
| Dimensions (W×H×D) | 275 × 225 × 136 mm | 225 × 143 × 278 mm | 225 × 143 × 278 mm |
| Weight | 7.5 kg | ≈ 8 kg | ≈ 8 kg |
| Price | €249.00 | €380.00 | €509.00 |
Shared across all SPD3303 models
Outputs (all models)
- Channel 1
- 0 – 32 V / 0 – 3.2 A
- Channel 2
- 0 – 32 V / 0 – 3.2 A
- Channel 3 (fixed)
- 2.5 / 3.3 / 5 V · 3.2 A (±8%)
- Total output power
- 220 W
Channel combining
- Series mode (max)
- up to 60 V
- Parallel mode
- up to 6.4 A (CH1 + CH2)
- Output modes
- Independent · Series · Parallel
Regulation & noise
- Line / load regulation (C.V.)
- ≤ 0.01% + 3 mV
- Ripple & noise (C.V.)
- ≤ 1 mVrms (5 Hz – 1 MHz)
- Transient recovery
- < 50 µs
- Line / load regulation (C.C.)
- ≤ 0.2% + 3 mA
- Ripple & noise (C.C.)
- ≤ 3 mArms
Features & general
- Memory save / recall
- 5 sets
- Front-panel key lock
- Yes
- Timing / sequenced output
- Yes
- AC input
- 100 / 120 / 220 / 230 V ±10%, 50/60 Hz
- Remote control
- SCPI + free EasyPower PC software
Specifications are taken from the official SPD3303C and SPD3303X / X-E datasheets and are subject to change; errors & omissions excepted. See the datasheets for full, guaranteed specifications and test conditions.
In the box
- Power cord
- USB cable
- Output test cords (2 sets · SPD3303X / X-E)
- Quick Start guide
- Calibration certificate
Not sure which model you need?
Tell us how you'll use it — bench, education, production or R&D — and we'll recommend the right SPD3303, with EU stock, support and calibration.
Frequently asked questions
What's the difference between the SPD3303C, SPD3303X-E and SPD3303X?
All three are the same 3-channel 220 W linear supply; they differ in display, resolution and connectivity. The SPD3303C has an LED display, 10 mV/10 mA resolution and USB. The SPD3303X-E adds a 4.3" colour TFT and LAN. The SPD3303X adds 10× finer 1 mV/1 mA resolution, higher accuracy and a real-time waveform display.
How many channels does it have and what are the voltages?
Three isolated outputs: two adjustable channels of 0–32 V / 3.2 A each, plus one fixed channel selectable to 2.5 V, 3.3 V or 5 V at 3.2 A — a ready-made logic rail. Total output power is 220 W.
Can I get more than 32 V or 3.2 A?
Yes. The two main channels can be combined: in series for up to 60 V, or in parallel for up to 6.4 A. Each channel can also be switched on or off independently.
Which model has the finest resolution and accuracy?
The SPD3303X. It sets and reads back to 1 mV / 1 mA with ±(0.03% + 10 mV) voltage accuracy, versus 10 mV / 10 mA and ±(0.5% + digits) on the SPD3303C and SPD3303X-E.
How do I control it from a PC?
Every model supports the SCPI command set and the free EasyPower PC software over USB. The SPD3303X and SPD3303X-E also add a LAN port for control over the network; the SPD3303C uses USB only.
Are these linear power supplies?
Yes — all SPD3303 models are linear designs with low ripple (≤ 1 mVrms), which suits sensitive analog, audio, RF and educational use. If you need four channels, higher current or more total power, see the SPD4000X series.