Tachometer inputs – Measurement Computing IOtech 640 Series User Manual
Page 73
Specifications are subject to change without notice.
IOtech 640 and 650 Series
879592
Specifications 11-3
Common mode rejection ratio:
640e; 640u: -70dB typ; -55dB max, at 1kHz
650e; 650u: -56dB typ; -41dB max, at 1kHz
Wideband noise:
640e; 640u: < 46µV RMS typ; 76µV RMS max
650e; 650u: < 184µV RMS typ; 304µV RMS max
IEPE bias source (640e, 640u, 650e, 650u channels 1 to 4):
Current: 2.1mA, 21V compliance (on/off software programmable per channel)
Impedance: >255k
Ω
IEPE fault detection thresholds: <1V (short), >20V (open)
IEPE fault indication: Software indicator, per channel
Analog Output (640e / 640u only)
Channels: 1
Signal connection: BNC
Frequency range: DC to 45kHz (-3.0dB)
Frequency accuracy: ±50ppm
DAC resolution: 24 bit
DAC Update Rate: 93.75 KSps
DAC type: Delta-sigma
Total Harmonic Distortion: 1kHz; -96dB typical
Total Harmonic Distortion + Noise: 1kHz; -87dB typical
Initial Powered Up Value: 0.0V for 640e; not guaranteed for 640u
Amplitude settings: 0 to 7Vp-p
Amplitude flatness (DC to 20kHz): ±0.02dB typ ±0.1dB max
Figure XIX. 640 Analog Out Flatness vs. Frequency
Amplitude accuracy at 1kHz: ±0.05dB typ 0.12dB max
Figure XX. 640 Analog Output Distortion
SNR (DC to 20kHz): 100dB typ 90dB max
Maximum load: 1k
Ω (50Ω with external power)
Waveform modes: Sine; Swept sine; Random; Burst; and Arbitrary
Output impedance: 50
Tachometer Inputs
Any analog input channel may be used as a tachometer input.