TPIC8101

KNOCK SENSOR INTERFACE

SLIS110A − APRIL 2003 − REVISED MAY 2005

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POST OFFICE BOX 655303

features

Frequency

− 4, 5, 6, 8, 10, 12, 16, 20, and 24 MHz

125

°C

applications

Characteristics

description

The TPIC8101 is a dual-channel signal processing IC for detection of premature detonation in combustion

engine. The two sensor channels are selectable through the SPI bus. The knock sensor typically provides an

electrical signal to the amplifier inputs. The sensed signal is processed through a programmable band-pass filter

to extract the frequency of interest (engine knock or ping signals). The band-pass filter eliminates any engine

background noise associated with combustion. The engine background noise is typically low in amplitude

compared to the predetonation noise.

The detected signal is full-wave rectified and integrated by use of the INT/HOLD signal. The digital output from

the integration stage is either converted to an analog signal, passed through an output buffer, or be read directly

by the SPI.

This analog buffered output may be interfaced to an A/D converter and read by the microprocessor. The digital

output may be directly interfaced to the microprocessor.

The data from the A/D enables the system to analyze the amount of retard timing for the next spark ignition timing

cycle.

With the microprocessor closed-loop system, advancing and retarding the spark timing optimize the load/RPM

conditions for a particular engine (data stored in RAM).

Copyright

 2003 − 2005, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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GND

OUT

NC

NC

INT/HOLD

CS

XIN

XOUT

CH1P

CH1N

CH1FB

CH2FB

CH2N

CH2P

TEST

SCLK

SDI

SDO

DW PACKAGE

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