CW501 Differential Probe with PicoScope

Hello All,

I am using a CW501 Differential Probe with a PicoScope 2206B but the waveform seems strange.

On top the waveform on the shunt with the PicoScope single-ended probe:
On the bottom the waveform with the differential probe:

Is that the normal behavior of the CW501 Differential Probe?
Would that be the PicoScope’s probe capacitance?

I apologize in advance for not being an expert in hardware and asking this question. :slight_smile:

Thanks,
André.

Hi Andre,

What’s the timescale on that? Looks like there is a BW or some filtering going on, which you shouldn’t run into. I can try to recreate here (also have a picoscope to test with).

How are you powering the probe (i.e., is it the PSU with the kit or external, and if external what power are you using?).

-Colin

Hi @coflynn, thank you for the answer.

The scale is 2ms/div:

I also did a capture with CW to check if it was the PicoScope, but it also seems odd.
Here’s a part of the waveform read by the CW:

Using this scope config:
cwlite Device
gain =
mode = low
gain = 0
db = -6.5
adc =
state = False
basic_mode = rising_edge
timeout = 60
offset = 460000
presamples = 0
samples = 24400
decimate = 1
trig_count = 590709
clock =
adc_src = clkgen_x4
adc_phase = 0
adc_freq = 29538459
adc_rate = 29538459.0
adc_locked = True
freq_ctr = 0
freq_ctr_src = extclk
clkgen_src = system
extclk_freq = 10000000
clkgen_mul = 2
clkgen_div = 26
clkgen_freq = 7384615.384615385
clkgen_locked = True
trigger =
triggers = tio4
module = basic
io =
tio1 = serial_rx
tio2 = serial_tx
tio3 = high_z
tio4 = high_z
pdid = high_z
pdic = high_z
nrst = high_z
glitch_hp = False
glitch_lp = False
extclk_src = hs1
hs2 = clkgen
target_pwr = True
glitch =
clk_src = target
width = 10.15625
width_fine = 0
offset = 10.15625
offset_fine = 0
trigger_src = manual
arm_timing = after_scope
ext_offset = 0
repeat = 1
output = clock_xor

The CW capture is the “last falling edge” of the waveform:

I am using the CW503 probe PSU.

Thanks,
André.

Hi @coflynn have you got time to look into that?

Thanks,
Andre.