V840

Features 4-channel digital delay generator in a C-size, register-based VXI module. Delay and width modes. 20 (19.53125) picosecond LSB resolution with 32-bit (83.9 ms) full-scale delay range. High agility allows rapid reprogramming of delays. Delay and width programming changes are limited by VXI bus transaction rate only. Fully programmable trigger threshold and output levels. 25 nSec insertion delay. Includes high-stability ovenized crystal oscillator timebase.

Description The model V840 is a single-width, C-size VXI module. It accepts a single trigger pulse input and generates four separately programmable sequences to create up to four complex delay-and-width outputs. The module features a 32-bit dynamic range, 20 pSec resolution, low jitter, and high rep-rate capability. In the delay mode all channels are triggered simultaneously. The module generates a T0 edge 25 nSec after the trigger, and four follwoing delays A, B, C, and D, each programmable from 0 to 83.9 mSec. In the width mode, channel A is triggered from the trigger source, while channel B is triggered from A. This allows the generation of a pulse whose incdience is determined by channel A's timing value and whose duration is determined by channel B's timing value. Similary, channels C and D can be combined into a second delay/width channel. The four outputs are each programmable for a select combination of T0, A, B, C, D, and an external expansion unit.

Specifications: Model V840


CONFORMANCE

• Complies with ANSI/IEEE 1014k-1987 VMEbus specifications. Meets the VXIC 1.4 VXI specification for register-based C-size module.

DEVICE TYPE:

• VXI Register based slave: A16:D32:D16: D08(EO) capability.

PACKAGING:

• Single width C-size module (233.35 mm x 340 mm).

TRIGGERING:

• Triggers can be selected from any of a number of sources: the front panel EXT, TRG, or AUX inputs; one of the two VXI ECLTRG lines; or from VMEbus command triggering.

REP RATE:

• Up to 2 MHz.

RANGE:

• 32 bits allows for a full scale range of 83.88608 mSec on all channels.

RESOLUTION:

• 19.53125 pSec LSB (equivalent to a clock rate of 51.2 GHz).

JITTER:

• Less than (100 pSec + 2 x 10^-9 x programmed delay RMS.

ACCURACY:

• ±500 pSec ± timebase stability.

TIMEBASE

• Ovenized crystal oscillator. Temperature coefficient less than 10 ppB/degree C; aging below 1 ppM/year. The V840 oscillator may be phase locked to a 10 MHz external reference via the front panel CLOCK I/O, to another V840 module timebase, or to the VXI CLK10 signal.

INPUTS:

• EXT TRG: Programmable level and slope up to ±5 volts, switchable 50 ohm termination. The module may also be triggered from either of the VXI ECLTRG lines, by a VXI bus command, or from an internal rate generator. AUX 1, 2: Two inputs with fixed threshold (1.8 Volts). may be used as additional sources of triggers.
• EXP IN: Expansion input allow multiple modules to be "chained" to allow the generation of more complex waveforms. This niput has a fixed ECL level threshold and ECL termination.
• CLOCK I/O: Selectable as an input or and output with TTL levels. This is used for locking multilple V840s to a single timebase.

OUTPUTS 1-4:

• Four outputs; each may be programmed combination of T0, the four delay channels, and an external term. Output levels are programmable from -2.5 to +5 volts from 50 ohms. Output rise time and falltime less than 3nSec. (Transition times are less than 1 nSec for ECL level swings).

CONNECTORS:

• SMA

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