VID Interface
Figure 5. Program 3, 2 s/div – Volkswagen Cold-Start Test Pulse, VW80000
The Single Cont..push-button selects between generating a single pulse on an input trigger event (push-
button or external trigger input) or continuous pulses until the next input trigger event.
In continuous mode, the Delay potentiometer adjusts the delay between successive pulses. At the
counterclockwise limit, the delay is 0 seconds; at the clockwise limit it is around 2 s. The gradient between
those two limits is linear.
Changing the program is only possible while no pulse generation is in progress. If the program is changed
during pulse generation, the board is registers and stores the new program selection, but the change does
not occur until completion or aborting of the present pulse and occurrence of a new input trigger event.
Changing the mode from single to continuous is also only possible while pulse generation is not in
progress. In the case of a mode change during pulse generation, the board registers and stores the new
mode, but the change does not occur until completion or aborting of the present pulse and occurrence of a
new input trigger event.
If the board is working in continuous mode, pressing the Single Cont. push-button switches the C LED off
and the S LED on. The generation of the present pulse finishes and after that, the output voltage goes
back to the default value. Now, for a single pulse, a new input trigger event is necessary.
The Output Enable push-button enables and disables the output voltage independent of the selected
program, mode, trigger event, or anything else. With it, one can always switch the buck converter directly
on or off.
4
VID Interface
To change the output voltage of a converter during operation, several approaches are possible. Probably
achievement of the fastest output voltage changes can be by using a VID interface (dynamic voltage
identification), known from the area of powering DSPs (digital signal processors). Depending on the
processor load, the VID interface adjusts core voltage to increase the computing power or to reduce the
losses.
6
Automotive Cranking Simulator User’s Guide
SLVU984 – December 2013
Copyright © 2013, Texas Instruments Incorporated
