Ap033 active probe – Atec LeCroy-AP033 User Manual

Page 2

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ISSUED: October 2001

AP033-OM-E Rev F

AP033 Active Probe

WARRANTED ELECTRICAL CHARACTERISTICS

Warranted characteristics are parameters with guaranteed
performance. Unless otherwise noted, tests are provided in the
Performance

Verification

Procedure

for

all

warranted

specifications.

LF Gain Accuracy:

2% into 50.0

Ω

load

measured at 1 kHz with 0 volt
offset

Common Mode Rejection Ratio

: (Probe head grounded, DC

Coupled,

1 Attenuation,

without external attenuator)

70 Hz

≥

3160:1

(70 dB)

1 MHz

≥

1000:1

(60 dB)

250 MHz

≥

5:1

(14 dB)

Notes:

Output impedance is 50

Ω,

intended to drive 50

Ω

. Add

uncertainty of termination impedance to accuracy.

LeCroy measures CMRR with a fixture that connects

the probe tip ground to the signal source ground. This
method is necessary to obtain a reproducible CMRR
measurement.

Often, users leave the probe tip ungrounded when

measuring high frequency signals. Not grounding the
probe tip can actually improve CMRR by allowing
some of the common mode signal to be impressed
across the entire length of the probe cable instead of
from probe tip to probe ground. The CMRR
improvement obtained without grounding the probe tip
depends on proximity to probe cable ground, and is
therefore nonreproducible.

LeCroy has chosen to use a reproducible method of

measurement, rather than obtain a more optimistic
measurement.