Siglent SPD4000X Series
Four independent, high-precision linear outputs in a single 3U half-rack instrument. 1 mV / 1 mA resolution, a 4.3" real-time waveform display, series/parallel channel combining and full web & SCPI control — from 240 W up to 400 W.
Four clean rails on one bench
Modern designs rarely run on a single voltage. A microcontroller board might need 3.3 V and 5 V logic rails, a ±15 V analog supply and a separate rail for a sensor or motor — all powered and switched together. The SPD4000X gives you four fully independent linear outputs in one instrument, so you can power a whole prototype without stacking three or four bench supplies.
Because it's a linear design, ripple and noise stay extremely low (≤ 6 mVpp) — important for op-amps, ADC/DAC front-ends, RF modules and audio. The 4.3" display shows live voltage, current and waveform charts per channel; list mode runs automated voltage/current sequences; and the embedded web server lets you drive everything from a browser. When you need more, combine CH2 and CH3 in series or parallel for higher voltage or current.
Built for precise, repeatable testing
Real-time waveform display
A 4.3" true-colour TFT (480×272) plots live voltage and current run-charts for all four channels, so you can see transients and load changes as they happen — not just a single number.
Web & SCPI control
USB and LAN are standard. The embedded web server runs in any browser with no software to install, and the full SCPI set plus a LabVIEW driver make the SPD4000X easy to fold into an automated test system.
Series / parallel / independent
Run all four outputs separately, or combine CH2 + CH3 in series for more voltage or in parallel for more current.
List / sequence mode
Program up to 50 steps of voltage/current with dwell times, or run one of 8 built-in sequences for automated profiles and ageing tests.
Protection & remote sense
Per-channel OVP and OCP guard your DUT, and remote sense (up to 0.6 V) keeps the voltage accurate right at the load.
Rear panel — every connection explained
All remote-control, sensing and mains connections sit on the back of the SPD4000X. The rear panel is identical across the three models — here is what each connector and control does.
Network port for SCPI control and the embedded web server — operate the supply from any browser, no software needed.
Direct PC connection for the SCPI command set and the LabVIEW driver. The optional USB-GPIB adapter also connects here.
Plug in a USB stick to save and recall setups and to import list/sequence files for multi-step output.
Sense terminals for the two main channels (CH2, CH3) that compensate voltage drop in the leads — up to 0.6 V — so the set voltage appears at the load.
Earth/ground post for tying your device-under-test or shielding to the instrument chassis ground.
Forced-air cooling that only speeds up as the load demands, keeping acoustic noise low on the bench.
Manual mains selector for 100 / 120 / 220 / 230 V, so the unit runs on any regional power grid.
IEC mains socket with an integrated fuse holder. Fuse rating depends on the selected voltage (e.g. T10A at 100/120 V, T3.15A at 220/230 V).
Three models — same features, different ratings
All three share the chassis, 4.3" display, resolution and control. Pick by the output you need most: voltage, current or total power.
- CH1: 6 V / 3.2 A
- CH2: 32 V / 3.2 A
- CH3: 32 V / 3.2 A
- CH4: 6 V / 3.2 A
Highest voltage per channel — dual 32 V mains for dual-rail analog and op-amp work.
- CH1: 15 V / 1.5 A
- CH2: 12 V / 10 A
- CH3: 12 V / 10 A
- CH4: 15 V / 1.5 A
Highest current — dual 10 A mains for high-current 12 V loads, motors and automotive.
- CH1: 15 V / 1.5 A
- CH2: 30 V / 6 A
- CH3: 30 V / 6 A
- CH4: 15 V / 1 A
Most total power — dual 30 V/6 A mains for the widest mix of voltage and current.
SPD4000X vs SPD3303X — what you gain
Both are Siglent linear supplies and share the same 1 mV / 1 mA setting resolution, 4.3" TFT waveform display and independent/series/parallel modes. Where the 3-channel SPD3303X covers basic dual-rail bench work, the SPD4000X adds a fourth fully-adjustable channel, more power and current, finer current readout, true list-mode sequencing, remote voltage sensing and embedded web control. The differences below are taken directly from both datasheets.
| Feature | SPD4000X | SPD3303X / X-E |
|---|---|---|
| Output channels | 4 fully adjustable | 3 (2 adjustable + 1 fixed 2.5/3.3/5 V) |
| Total output power | 240 / 285 / 400 W | 220 W |
| Max current per channel | up to 10 A (SPD4121X) | 3.2 A |
| Parallel current (2 ch) | up to 20 A (SPD4121X) | 6.4 A |
| Current display | 5-digit | 4-digit |
| Sequencing | List mode: 50 steps + 8 built-in | Panel timing output |
| Remote voltage sense | Yes (up to 0.6 V) | No |
| Remote interfaces | USB, LAN, embedded web server (USB-GPIB optional) | USB Device, LAN |
| Ripple & noise (rms) | 600 µV | ≤ 1 mV |
| Shared | Linear regulation · 1 mV/1 mA resolution · 4.3" TFT 480×272 with waveform display · independent/series/parallel · < 50 µs transient recovery · 100/120/220/230 V input | |
Figures from the SPD4000X and SPD3303X datasheets. The SPD3303X remains a strong choice for simple 2–3 rail bench use; the SPD4000X suits work needing a fourth channel, higher current, sequencing or automated/remote control.
Full specifications
Output ratings differ per model; everything below the table is shared across the whole series.
| Specification | SPD4323X | SPD4121X | SPD4306X |
|---|---|---|---|
| Output channels | 4 | 4 | 4 |
| CH1 rated V / I | 6 V / 3.2 A | 15 V / 1.5 A | 15 V / 1.5 A |
| CH2 rated V / I | 32 V / 3.2 A | 12 V / 10 A | 30 V / 6 A |
| CH3 rated V / I | 32 V / 3.2 A | 12 V / 10 A | 30 V / 6 A |
| CH4 rated V / I | 6 V / 3.2 A | 15 V / 1.5 A | 15 V / 1 A |
| CH2+CH3 in series | 60 V / 3.2 A | 24 V / 10 A | 60 V / 6 A |
| CH2+CH3 in parallel | 32 V / 6.4 A | 12 V / 20 A | 30 V / 12 A |
| Total rated power | 240 W | 285 W | 400 W |
| Max input power | 470 W / 570 VA | 620 W / 740 VA | 720 W / 910 VA |
Shared across all SPD4000X models
Resolution & accuracy
- Voltage / current resolution
- 1 mV / 1 mA
- Voltage programming & readback
- ± (0.03% of reading + 10 mV)
- Current programming & readback
- ± (0.3% of reading + 10 mA)
- Display
- 5-digit voltage & current
Regulation & noise (C.V.)
- Line regulation
- 0.01% + 2 mV
- Load regulation (remote sense)
- 0.01% + 2 mV
- Ripple & noise
- ≤ 6 mVpp · 600 µVrms
- Transient response time
- < 50 µs
- Remote sense compensation
- up to 0.6 V
Control & interfaces
- Display
- 4.3" TFT-LCD (480 × 272)
- Standard interfaces
- USB (Host & Device), LAN
- Optional interface
- USB-GPIB adapter
- Remote control
- Embedded web server, SCPI, LabVIEW driver
- List / sequence mode
- 50 steps + 8 built-in sequences
Protection & general
- Over-voltage protection (OVP)
- 10% – 110% of rated voltage
- Over-current protection (OCP)
- 0 – 110% of rated current
- AC input
- 100/120/220/230 V ±10%, 50/60 Hz
- Dimensions (W×H×D)
- 221 × 133 × 360 mm (3U half-rack)
- Weight
- 12 kg · Warranty 3 years
Specifications are taken from the official SPD4000X datasheet and are subject to change; errors & omissions excepted. See the datasheet for full, guaranteed specifications and test conditions.
In the box
- Power cord
- USB cable
- 4× 3 A output test cords
- Quick Start guide
- Calibration certificate
Optional: USB-GPIB adapter for GPIB-based automation.
Need help choosing a model?
Tell us the voltages, currents and channels your project needs and we'll recommend the right SPD4000X — with EU stock, support and calibration.
Frequently asked questions
What is the Siglent SPD4000X series?
The SPD4000X is a family of 4-channel programmable linear DC power supplies. Each unit has four independent, controllable outputs, a 4.3" colour waveform display, 1 mV / 1 mA resolution and web & SCPI control. Three models cover 240 W, 285 W and 400 W of total output power.
What's the difference between the SPD4323X, SPD4121X and SPD4306X?
They share the same chassis, display and features but differ in output ratings: the SPD4323X gives the highest voltage (dual 32 V/3.2 A, 240 W), the SPD4121X the highest current (dual 12 V/10 A, 285 W) and the SPD4306X the most total power (dual 30 V/6 A, 400 W). See the comparison table above.
Can I combine channels for more voltage or current?
Yes. On every model the two main channels (CH2 and CH3) can be connected in series for higher voltage or in parallel for higher current — for example up to 60 V on the SPD4323X/SPD4306X or up to 20 A on the SPD4121X.
Why choose a linear supply instead of a switching supply?
Linear supplies deliver the lowest noise and ripple (≤ 6 mVpp here) and very fast transient response, which makes them ideal for sensitive analog, audio, RF and R&D work. For wide-range, high-power output choose a switching supply such as the Siglent SPS series.
How do I control the SPD4000X remotely?
USB and LAN are standard. The embedded web server lets you monitor and control the supply from any browser with no software to install, and the full SCPI command set plus a LabVIEW driver support test automation. A USB-GPIB adapter is available as an option.
Does it support remote voltage sensing?
Yes — the high-current channel supports remote sense to compensate for voltage drop in the test leads, with up to 0.6 V of compensation, so the voltage at your load stays accurate.