HIP9011EVAL1Z Intersil, HIP9011EVAL1Z Datasheet - Page 3

• Manufacturer Part Number: HIP9011EVAL1Z
• Description: BOARD EVALUATION FOR HIP9011
• Manufacturer: Intersil

Specifications of HIP9011EVAL1Z

• Main Purpose: Special Purpose, Engine Knock Signal Processor
• Utilized Ic / Part: HIP9011
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -

display is the 200kHz clock signal that only appears during the
integration portion of the sample cycle. This signal causes
aliasing or a “low frequency beat” in the oscilloscope display
between the 500 samples and the 200kHz pulses appearing on
the ramp only during the integration interval. Once the signal is
acquired, the INTOUT signal during the hold period remains
constant and free of the 200kHz pulses until the next integration
period. The sample and hold circuit within the HIP9011 is timed
so that it only samples during a non pulse period, thus
preventing it from acquiring either peaks or valleys.
The lower trace of Figure 5 more accurately depicts the
INTOUT waveform. Note the 200kHz clock signal on the
integrator ramp. One million samples were used for this
display. Also note that INTOUT is constant between
integration cycles and shows no 200kHz pulses.
For observation purposes only, or when working with a
digital oscilloscope with limited samples, an external anti
aliasing filter may be assembled with a series 51k resistor
and a 510pF capacitor to ground. The filter attenuates the
internal 200kHz clock signal during integration, For
operation with a sampling A/D converter that is strobed and
samples after the integration cycle, no filter is needed.
Laboratory Setup
It is desirable to get a “feeling” for the operation of the
HIP9011 before proceeding to an evaluation with an engine,
Figure 6 shows a bench test setup where this can be easily
accomplished.
One generator is used to provide the INT/HOLD signal to the
Evaluation Board. In the actual application this signal would be
supplied by the engine controller. The width of this signal may
vary from several hundred microseconds to several
milliseconds depending upon the engine rpm and engine type.
Generally, there is a large signal at high engine rpms and lower
signals at low rpms. At the lower rpm, the integration period
may be extended to gain more samples and effectively produce
high sensitivity to obtain more output.
3
FIGURE 3. WAVEFORMS ASSOCIATED WITH THE HIP9011
Application Note 9770
The second generator provides the signal that serves as a
knock signal. It is interesting to note the variation of the
integrator output, INTOUT, as the IC filter frequency or oscillator
frequency is varied from 200Hz to 100kHz. Figure 4 shows the
IC’s filter response as a sweep frequency signal is applied to
only the filter circuit for five selected filter frequencies from
1.22kHz to 19.98kHz. These curves were taken only of the
filters to show their response and comparatively constant
output through out the entire filter frequency range.
Figure 7 shows the HIP9011 connected to an engine. The
microcontroller with inputs from the engine, provides the
INT/HOLD signal to initiate operation of the integrator within
the knock signal processing IC.
Evaluation Board
Figure 8 shows the schematic diagram of the evaluation board.
A 4MHz crystal is supplied with the board. 4MHz ceramic
resonators such as the TDK FRC4.0MCS have been
successfully used in the board. Three pins are provided on the
board to accept resonators to replace the crystal.
A prewired input amplifier configuration board is provided as
shown in Figure 9. This board is connected for single ended
operation.
Figure 10 shows the schematic diagram for a differential
input board that may be wired for the HIP9011. This may be
fabricated with the one generic blank board supplied with the
evaluation board.
Figure 11 is a top view of the evaluation board.
Software Displays
Figure 12 shows the display for the HIP9011 appearing on the
computer when using the Evaluation Board in a Microsoft®
Windows® setup. In some Windows setups the text displayed
may override the boxes and be difficult to read due to computer
settings. This can be corrected by changing the font size on the
computer. This is described in the “Installing Knock Signal
Processor Software” section of this application note.
November 6, 2006
AN9770.1