VISTEK V1626 digital to analogue
converter
10
Issue 1
4.
CALIBRATION OF V1626 DAC MODULE
4.1
Introduction
This section is intended to provide sufficient information to allow an engineer to calibrate the DAC system.
Calibration should only be carried out if the unit has been mal-adjusted, or if drift has occurred over an
extended period of time.
It should be appreciated that calibration is not a duplication of the alignment procedure which should be
referred to if a repair has been carried to the module.
4.2
Test Equipment
100 MHz dual channel oscilloscope.
Tektronix TSG-422 10 bit serial test signal generator.
Tektronix WFM601i Serial signal analyser.
Tektronix 1781 test set
Digital multimeter
Standard RS trim tool
4.3
Environmental
The calibration should be carried out at a nominal temperature of 20 degrees Celsius.
Test Equipment Connection
Connect the serial digital outputs of the TSG422 to inputs of the unit under test.
Connect one of the serial digital outputs from the unit under test to the VFM601i via a cable clone. Initially set
the cable clone to zero metres.
Connect the Y Pb, Pr outputs of the unit under test to TEK1781 set. Use cables of the same type and equal
length (this is necessary for luma-chroma delay calibration).
