The HIP9010 is used to provide a method of detecting premature detonation or “Knock” in automotive engines.
A block diagram of this IC is shown in Figure 1. The chip alternately selects one of the two sensors mounted on the engine block. Two programmable bandpass filters process the signal from both sensors, and divides the signal into two channels. When the engine is not knocking, programmable gain adjust stages are set to ensure that both the reference channel and the knock channel contain similar energies. This technique ensures that the detection system is comparatively immune to changes in the engine background noise level. When the engine is knocking, the energy in the knock channel increases.

Features
• Two Sensor Inputs
• Microprocessor Programmable
• Accurate and Stable Filter Elements
• Digitally Programmable Gain
• Digitally Programmable Time Constants
• Digitally Programmable Filter Characteristics
• On-Chip Clock
• Operating Temperature Range -40°C to 125°C

Applications
• Engine Knock Detector Processor
• Analog Signal Processing where Controllable Filter Characteristics are Required