SIGLENT SDP6150A 100MHz High Voltage Differential Probe
The SIGLENT SDP6150A is a 100 MHz high voltage differential probe for safe and accurate measurement of floating and high voltage signals up to ±1500 V. With 50X/500X attenuation, high input impedance, low input capacitance, overrange indication and SAPBUS integration for compatible SIGLENT oscilloscopes, it is ideal for power electronics, inverter, motor drive and switching power supply measurements.
100 MHz differential high-voltage probe, ±1,500 V
The SDP6150A measures up to ±1,500 V between its two tips with 100 MHz of bandwidth and ±2% DC accuracy. It takes its power and its configuration from the oscilloscope over SAPBus, so the scope names the probe, sets its attenuation and reads the channel directly in volts.
Neither tip is referenced to earth, which is the whole point: you can put it across a floating rail, a high-side gate-source or a mains-referenced switch node without connecting that point to earth through the instrument. It is powered by the oscilloscope itself, over SAPBus. Two attenuation ratios — 50X for the lowest noise and 500X for the full range — plus a switchable bandwidth limit and an audible over-range alarm.
Check your oscilloscope first
The SDP6150A is powered and configured by the oscilloscope over SAPBus, so it needs a SAPBus input: the SDS7000A, SDS6000A, SDS6000L, SDS5000X and SDS3000X HD series. It will not work on an SDS2000X HD or any older model with plain BNC inputs. If you want the same measurement on any brand of scope, the DPB6150A is the USB-C powered equivalent — and it carries a higher 1000 V CAT III rating.
What it does well
The things that decide whether a high-voltage measurement is both accurate and safe.
No earth reference at the tips
A passive probe’s ground clip is wired to the scope chassis and therefore to mains earth. This one measures the difference between two floating points and sends only that to the oscilloscope, so the circuit never sees an earth connection.
100 MHz bandwidth
Enough to follow the switching edge itself rather than the envelope it sits in — which is where the losses and the ringing actually live.
Configured by the oscilloscope
SAPBus carries power, identification and control down one connector. Attenuation and range appear in the channel dialog automatically — nothing to set twice, nothing to get wrong.
Two ratios, switched on the body
50X keeps noise down on small signals; 500X takes the full ±1,500 V. Pick the lowest ratio your signal fits inside, because every step up costs resolution.
Audible over-range alarm
A red indicator and a buzzer when the input exceeds the selected range, so a clipped trace gets noticed on the bench. The alarm can be silenced when it becomes a nuisance.
Rated 600 V CAT III · 1000 V CAT II
The category matters as much as the voltage — it describes the transient energy the installation can deliver, not just the level it sits at.
Key specifications
- Bandwidth 100 MHz (−3 dB)
- Maximum differential input ±1,500 V (DC + AC)
- Attenuation 50X and 500X
- ±2% DC accuracy
- Maximum measurable: ±150 V at 50X, ±1,500 V at 500X
- 600 V CAT III · 1000 V CAT II
- Switchable bandwidth limit
- Powered by the oscilloscope over SAPBus
Application examples
Half-bridge and gate-drive measurement
High-side gate-source voltage on a bridge is floating by definition. This is the measurement that destroys probes and channels when it is attempted with a passive probe and a ground clip.
SiC and GaN converter development
Fast wide-bandgap edges with several hundred volts of swing. Bandwidth decides whether you see the real overshoot and ringing or a rounded approximation of them.
Motor drives and inverters
Phase-to-phase and DC-link voltage on a drive, where nothing in the measurement is at earth potential and the common-mode swing is large.
Mains and power-line work
Directly across a live conductor, safely, with the CAT rating matched to where you are probing.
Power supply design and verification
Switch-node voltage, snubber behaviour and rectifier stress — the measurements that decide component ratings and efficiency.
Specifications
| Bandwidth (−3 dB) | 100 MHz |
|---|---|
| Maximum input differential voltage | ±1,500 V (DC + AC) |
| Attenuation ratios | 50X and 500X |
| Maximum measurable voltage | ±150 V at 50X · ±1,500 V at 500X |
| DC accuracy | ±2% |
| Rated voltage to earth | 600 V CAT III · 1000 V CAT II |
| Bandwidth limit | Switchable, full or limited |
| Over-range indication | Red indicator plus audible alarm (can be silenced) |
| Oscilloscope connection | SAPBus — Siglent oscilloscopes only |
| Power | Supplied by the oscilloscope through SAPBus |
Specifications as published by SIGLENT. Errors and omissions excepted; specifications may change without notice. Differential voltage is measured between the two tips; the rated voltage to earth is how far the pair may float. Both limits apply at the same time.
In the box
- Differential probe
- Instruction manual
- Test report
Tell us where you are probing
The voltage between the two points, how far they float above earth, how fast the signal moves and which oscilloscope you own. Those four answers pick the probe — and we will say plainly when a cheaper one covers it.