Siglent SPD4121X 4 channel 285W power supply
The Siglent SPD4121X is a 4-Channel DC Linear Programmable Power Supply offers a total output power of 285W with a resolution of 1mV/1mA. The maximum voltage and current for each channel are as follows:
- CH1: 15V/1.5A
- CH2: 12V/10A
- CH3: 12V/10A
- CH4: 15V/1.5A
SPD4121X — 4-channel 285 W linear power supply
The SPD4121X is the high-current model: two 0–12 V / 10 A channels for power-hungry loads plus two 0–15 V / 1.5 A channels for control and instrumentation rails — 285 W in total from four independently controlled linear outputs.
Put CH2 and CH3 in parallel and you have 20 A at 12 V from a single pair of terminals; in series they reach 24 V at 10 A. Remote sense on the high-current channels compensates up to 0.6 V of lead drop, which is exactly what you need when 20 amps is flowing through your test leads.
Four rails you can actually watch
A display that shows every channel at once, and the tools to sequence and monitor them.
All four channels, five digits each
The 4.3″ colour TFT shows every channel simultaneously with a 5-digit voltage and current readout — set values, measured values and the CV/CC mode of each rail in one glance. Resolution is 1 mV / 1 mA with ±(0.03% + 10 mV) accuracy, so the number on screen is the number at the terminals. The 2W/4W indicator tells you at a glance which channels are running remote sense.
Real-time waveform view & recording
Plot voltage and current for all four channels against time and watch inrush, sequencing and load steps as they happen — then record the run to a CSV file on a USB stick. Combined with the list mode (50 steps per sequence, 8 stored sets), you can run a start-up profile or a margin sweep standalone and keep the evidence of what the rails actually did.
Independent, series or parallel
All four outputs switch on and off individually or together. Pair CH2 and CH3 in series for 24 V / 10 A or in parallel for 12 V / 20 A — the supply handles the master–slave tracking, and the terminals are labelled so the wiring is obvious.
List mode — test sequences without a PC
Enter voltage, current and duration per step — up to 50 steps, 8 stored sequences, with repeat count and continuous looping. Import a list from a USB stick for longer profiles. Power-cycle endurance, staged start-up and margin sweeps run standalone.
Web control — nothing to install
The embedded web server puts a full control panel in any browser on the network — set and read every channel, and even build list sequences. Handy for a supply in a rack, a screened room or a climate chamber. Full SCPI and a LabVIEW driver cover scripted control.
4-wire sense — connector included
The sense interface plugs into the rear terminal block and compensates up to 0.6 V of lead drop, so the voltage at your load is the voltage you set — the difference between guessing and measuring when real current is flowing. It ships in the box, not as an extra.
Key features
- Four independently controlled linear outputs — CH1 0–15 V / 1.5 A, CH2 0–12 V / 10 A, CH3 0–12 V / 10 A, CH4 0–15 V / 1.5 A
- Total output power 285 W · series 24 V / 10 A · parallel 12 V / 20 A (CH2 + CH3)
- 1 mV / 1 mA setting resolution with a 5-digit voltage and current readout per channel
- 4.3″ colour TFT with real-time waveform display — watch all four rails change over time
- Linear design: 600 µVrms ripple, < 50 µs transient recovery, ±(0.03% + 10 mV) accuracy
- Remote voltage sense compensates up to 0.6 V of lead drop on the high-current channel
- List mode — 50 steps per sequence, 8 stored sets, importable from a USB stick
- USB & LAN standard with an embedded web server — control from a browser, no software to install
Application examples
Automotive 12 V electronics
ECUs, lighting, pumps and infotainment modules draw real current. Two 10 A channels (20 A in parallel) supply them at their native 12 V rail, with remote sense keeping the voltage right at the connector rather than at the supply.
Motors, actuators and heaters
High-current linear output with hard limits lets you bring a motor driver up gradually and watch the current on a 5-digit readout — without the switching noise a cheap SMPS bench supply sprays across your measurements.
Battery and charging development
Charge and discharge currents in the ampere range with 1 mA resolution on the readback, plus OVP as a safety net and the list mode to run staged charge profiles standalone.
Power-rail integrity work
Remote sense removes the lead drop that makes high-current measurements lie. Combined with 600 µVrms ripple and < 50 µs transient recovery, the rail your DUT sees is the rail you set.
Automated racks
USB and LAN are standard with full SCPI and a LabVIEW driver, and the embedded web server lets a colleague check the supply from a browser without installing anything.
Every angle
The SPD4121X up close — note the remote-sense terminals and LAN port on the rear.
Specifications
| Output channels | 4 independently controlled linear outputs — CH1 0 – 15 V / 1.5 A · CH2 0 – 12 V / 10 A · CH3 0 – 12 V / 10 A · CH4 0 – 15 V / 1.5 A |
| Total rated output power | 285 W |
| Series mode (CH2 + CH3) | 24 V / 10 A — load regulation ≤ 200 mV |
| Parallel mode (CH2 + CH3) | 12 V / 20 A |
| Display | 4.3″ TFT-LCD (480 × 272) · 5-digit voltage & current · real-time waveform and timer views |
| Setting resolution | 1 mV / 1 mA |
| Voltage accuracy | ± (0.03% of reading + 10 mV) — programming and readback |
| Current accuracy | ± (0.3% of reading + 10 mA) — programming and readback |
| Ripple & noise (C.V.) | 6 mVp-p (20 MHz BW) · 600 µVrms (5 Hz – 1 MHz) |
| Transient response | < 50 µs to within 0.1% + 50 mV for a 50–100% load step |
| Remote sense | 2-wire / 4-wire — up to 0.6 V compensation on the high-current channel |
| List mode | 50 steps per sequence · 8 stored sequences · import from USB · timing accuracy < 50 ms |
| Protection | OVP 10–110% of rated voltage · OCP 0–110% of rated current |
| Connectivity | USB (Type A host + Type B device) · LAN · embedded web server · SCPI + LabVIEW driver · USB-GPIB optional |
| AC input | 100 / 120 / 220 / 230 V ±10%, 50/60 Hz — rear selector · max 620 W, 740 VA |
| Fuse | 100/120 V: T10A 250V · 220/230 V: T3.15A 250V |
| Dimensions & weight | 221 × 133 × 360 mm (3U half rack) · 12 kg |
From the official SPD4000X series datasheet (EN01C); subject to change, errors & omissions excepted.
In the box
Everything included as standard with your SPD4121X — including the 4-wire sense connector.
Accessories & related
The other two SPD4000X models share this chassis, display and control set — only the output ratings differ.
Wider voltage instead of current: two 32 V / 3.2 A rails, series to 60 V — and the lowest price in the series.
More voltage and more power: 30 V / 6 A main channels, 400 W total, series to 60 V.
19″ rack mount kit, 3U — holds two SPD4000X supplies side by side (instruments not included).
30 A rated leads for the high-current channels — the right cross-section when CH2 and CH3 run in parallel.
Not sure which SPD4000X fits?
Tell us the rails your product needs — voltages, currents and how many at once — and we will confirm which of the three models covers them with headroom.