Teledyne LeCroy AP033 - Manual (Page 12)

AP033 Active Differential Probe
6 922260-00 Rev A
4
Teledyne 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 non-reproducible.
Teledyne LeCroy has chosen to use a reproducible method of measurement, rather than obtain a more
optimistic measurement.
Typical Electrical Characteristics
Typical characteristics are parameters with no guaranteed performance. Tests for typical
characteristics are not provided in the Performance Verification Procedure.
Bandwidth, probe only (-3 dB): DC to 500 MHz
Risetime, probe only: ≤ 700 ps (÷10 Attenuation)
≤ 875 ps (÷1 Attenuation)
Residual Autobalance Offset (Ref. to input): ≤ 100 μV (÷1 Attenuation)
≤ 1.5 mV (÷10 Attenuation)
Differential Offset Range: ±400 mV (÷1 Attenuation)
± 4 V (÷10 Attenuation)
± 40 V (÷100 Attenuation)
CMRR: See Figure 1.
Input Resistance (each side to ground): 1 M Ω
Input Capacitance (between inputs): < 1.6 pF (÷10 Attenuation)
(each side to ground): < 3.1 pF (÷1 Attenuation)
Noise (referred to input, 5 to 1000 MHz): 6 nV/√Hz (÷1 Attenuation, 10X Gain)
10 nV/√Hz (÷1 Attenuation, 1X Gain)
60 nV/√Hz (÷10 Attenuation, 10X Gain)
115 nV/√Hz (÷10 Attenuation, 1X Gain)
Output Impedance: 50 Ω nominal, intended to drive 50 Ω
Harmonic Distortion (3rd order distortion): -52 dB below fundamental (200 mV
p-p
output at 100 MHz)
(3rd order intercept): +15 dBm (at 100 MHz measured at output)
AC Coupling LF Cutoff (-3dB): 16 Hz