Siglent CP4050 1 MHz 140 Amp Current Probe
The Siglent CP4050 is a high-performance current probe designed for accurate and reliable measurement of AC and DC currents. With a wide bandwidth of up to 1 MHz and a peak current measurement capability of 140 A, this probe is ideal for various industrial and engineering applications. Its precision and versatility make it a valuable tool for professionals in power electronics, motor drives, and circuit design.
140 A AC/DC current probe, DC–1 MHz
The CP4050 is the fast one in the CP4000 family: DC to 1 MHz with a 350 ns rise time, three times the bandwidth of anything else in the range. It also has the most sensitive output of the family at 500 mV/A, resolving from 20 mA, while still carrying 140 A peak.
The output is a voltage on a plain BNC at a stated millivolts per amp, so it works with any oscilloscope of any brand — and with a multimeter through a BNC-to-banana adapter. A slide switch picks the range, a knob nulls the residual magnetism in the core before you measure, and the supplied 9 V adapter powers it. Nothing to configure, nothing proprietary.
What it does well
The things that decide whether a current measurement can be trusted.
True AC and DC
A Hall-effect core reads direct current as well as alternating, so a DC bus, a battery discharge or the standing current in a supply rail shows up as a real level — not a signal an AC-only clamp would miss entirely.
Works with any oscilloscope
Plain BNC output at 500 mV/A or 50 mV/A. Set the channel to match and read amps straight off the screen. No proprietary bus, no scope-brand lock-in.
1 MHz, and 350 ns rise time
Enough to follow switch-node and inductor current in a real switch-mode supply, not just the mains-frequency envelope. This is where a current probe stops being a meter replacement and becomes a design tool.
500 mV/A resolves from 20 mA
Ten times the sensitivity of the CP4070 range. Small ripple and standby currents are real traces, not noise.
Zero before you measure
Clamping around iron leaves a remanent field that offsets every later DC reading. The zero adjustment nulls it in a second — the step that decides whether a DC current measurement can be trusted.
Rated for mains work
300 V CAT III · 600 V CAT II, with jaws that close over conductors up to 10.3 mm.
Key specifications
- DC–1 MHz (−3 dB), rise time 0.35 µs
- 50 Arms continuous · 140 A peak
- Ranges 500 mV/A and 50 mV/A
- Jaws accept conductors up to 10.3 mm
- Powered by the supplied 9 V adapter
- Plain BNC output — any oscilloscope, any brand
- Also reads on a multimeter with a BNC-banana adapter
- 300 V CAT III · 600 V CAT II
Application examples
Switch-mode supply development
Primary switch, inductor and output current with the bandwidth to see the edges that carry the losses.
Power-factor and harmonic work
1 MHz covers the fundamental and a long way into the harmonics that shape a real current waveform.
Ripple and small-signal current
The 500 mV/A range resolves from 20 mA, so output ripple current is measurable rather than inferred.
Inrush with detail
140 A of headroom, and enough speed to show the shape of the first few microseconds rather than an envelope.
Specifications
| Bandwidth | DC–1 MHz (−3 dB) |
|---|---|
| Rise time | 0.35 µs |
| Maximum continuous current | 50 Arms |
| Peak current | 140 A |
| Range switch | 500 mV/A and 50 mV/A |
| DC accuracy | ±3% ±20 mA at 500 mV/A (20 mA–14 A peak) ±4% ±200 mA at 50 mV/A (200 mA–100 A peak) ±15% max at 50 mV/A (100–140 A peak) |
| Power supply | DC 9 V adapter (supplied) |
| Maximum rated voltage to earth | 300 V CAT III · 600 V CAT II |
| Maximum conductor size | 10.3 mm |
| Output | BNC |
| Cable length | 100 cm |
| Weight | 310 g |
Taken from the SIGLENT Probe Data Sheet. Errors and omissions excepted; specifications may change without notice.
In the box
- Current probe
- 9 V DC adapter
- Instruction manual
Not sure this is the right probe?
Tell us the current you expect, the frequency it moves at, which oscilloscope you own and whether there is DC in the measurement. We will tell you which probe fits — including when a cheaper one covers it.