Zarlink Le51HE001V User Manual - page 19
Le51HE001V
Eval Board User Guide
15
Zarlink Semiconductor Inc.
5.2
TESTING THE AISN PATH
The first path is via the AISN gain block. This test will allowing the user to see how AISN can affect
a signal by simply changing the AISN Gain value and writing that value to the QLSLAC device.
Once again, you can either load the script, "aisn_path.tcl" or follow the procedures.
To test the AISN function, do the following:
•
Input a 1V
PP
, 1 kHz sine wave to VIN1 of channel 1, and connect an oscilloscope to the
VOUT1 BNC.
–
Click on Wrt/Rd AISN & Analog Gains button.
–
Click on +0.6250 and press Write.
–
The signal should jump to approximately 568 mV
RMS
.
–
Click on -0.625 and press Write.
–
The signal will drop to approximately 131m mV
RMS.
The signal is now looped through the AISN block in the QLSLAC device. Selecting any of the values
in the AISN Gain screen will immediately affect the signal.
Note:
Before continuing to the next test, set the AISN Gain block back to cut-off.
5.3
TESTING THE AX, Z, AND AR PATHS
The second test path is via the AX, Z, and AR blocks only. This test causes the 1 kHz signal, input
to channel 1, to be looped through a specific path, and output to the VOUT1 BNC. Independently
changing the AX, AR, and Z Gain values and writing that value(s) to the QLSLAC will affect the
output signal, therefore allowing the user to see how these blocks can affect a signal. Either run
the "ax_z_ar_path.tcl" script or perform the steps below.
1. Click on the Wrt/Rd Operating Functions button, then do as follows:
a) Enable Z filter by setting it to a "1".
b) Write Operating Functions.
2. Click on the Wrt/Rd Z filter (FIR & IIR) button, then enter "1" for the decimal value of each chan-
nel to activate the Z filter.
Connect an external 1 kHz supplied by a signal generator:
•
Once the Z filter is enabled the signal will become 0.345 mV
RMS
.
•
To have a better understanding how the AX and AR filters affect the signal, open the AISN
Programming menu and change the AX or AR from a "0" to a "1". (Do not change AX and AR
simultaneously as this will have no visible effect on the signal since AX provides a +6.02 dB
gain and AR attenuates by a 6.02 dB gain.)
•
If setting AX = 1 (AR = 0), the signal becomes a 0.690 mV
RMS
.
•
If setting AR = 1 (AX = 0), the signal becomes a 0.172 mV
RMS
.
When using a DVM for measuring the peak-to-peak AC signal, from a generator, the DVM will
always display the Root Means Square (RMS) value. An oscilloscope is designed to display the
V
PP
value, as well as the shape, of the signal. To convert from V
PP
to RMS refer to the formula
below.
RMS
TRUE
2.828
----------------------
=