The V490 includes 16 independent acquisition channels, each with a programmable-gain differential amplifier, analog anti-aliasing filter, 16-bit analog-to-digital converter, and digital post-processing. With a dedicated A/D converter per channel, the V490 provides true simultaneous sampling, which can be extended across multiple V490s or triggered from an external TTL signal.
Both realtime and FIFO buffered data are simultaneously available, with each path having its own programmable digital filter. FIFO load rates are internally programmable to up to 500 Ks/s, or may be externally triggered. Digital processing allows emulation/replacement of a classic Neff type architecture, namely a preamp and analog lowpass filter feeding a low-aperture-jitter triggerable ADC per channel, while adding the ability to watch the real-time data at any time without disturbing the FIFO acquisition.
The V490 also integrates with Highland's advanced test and calibration architecture, allowing each channel to be relay switched to a dedicated calibration bus. The calibration bus allows one or many modules to be automatically connected to an external DVM, providing traceability with no need to disturb field wiring. Automatic built-in self-test is also available.
FUNCTION | 16-channel differential analog-to-digital converter |
DEVICE TYPE | 16-bit VME register-based slave: A24:A16:D16:D32; Implements 256 16-bit registers at switch selectable addresses in the VME 16 or 24 bit addressing spaces |
RANGES | Programmable per channel ± 10.24 mV ± 40.96 mV ± 160 mV ± 640 mV ± 2.56 V ± 10.24 V ± 40.96 V |
RESOLUTION | 16 bits, 0.313 µV on 10.24 mV range |
INPUT IMPEDANCE | > 500 K to ground, each differential input |
ACCURACY | ± 0.05% of range ± 20 µV ± 5 µV/°C |
CMRR | 100 dB typical on 10 mV range to 60 dB typical on 40 V range CM range ± 10 V, ± 140 V on 10 and 40 V ranges |
SAMPLE RATE | 500 Ks/s FIFO path has programmable trigger rate |
BANDWIDTH | -3 dB at 80 KHz typical, 9 KHz on 10 mV range (see manual for extended bandwidth specifications) |
FILTERING | Analog, 80 KHz 5-pole pre-ADC lowpass Digital, 1 Hz to 50 KHz, 8-pole Bessel or Butterworth |
PROTECTION | ± 250 volts either input to ground |
OPERATING TEMPERATURE | 0 to 60°C; extended MIL/COTS ranges available |
CALIBRATION INTERVAL | One year |
POWER | Standard VME supplies: + 5 volts, 0.8 amp max +12 volts, 250 mA max -12 volts, 250 mA max |
CONNECTORS | Two D25 female, each 8 channels One D9 male analog test One SMB trigger i/o |
INDICATORS | LEDs indicate VME access, CPU activity, error conditions Additional LED is user programmable |
PACKAGING | 6U single-wide VME module |
CONFORMANCE | ANSI/VITA 1-1994 (R2002) VMEbus spec; does not support byte writes |
V490-1: 16-channel VME multi-range digitizer
V490-2: 16-channel VME multi-range digitizer with BIST