Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear-IC



  

SLIS110A − APRIL 2003 − REVISED MAY 2005

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

features

D Dual-Channel Knock Sensor Interface

D Programmable Input Frequency Prescaler

(OSC

)

D Serial Interface With Microprocessor (SPI)

D Programmable Gain

D Programmable Band-Pass Filter Center

Frequency

D External Clock Frequencies up to 24 MHz

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

D Programmable Integrator Time Constants

D Operating Temperature Range −40°C to

125°C

applications

D Engine Knock Detector Signal Processing

D Analog Signal Processing With Filter

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).

       ! "#

"     $   % 

"" &'# " ( "  !' !"

(  !! #

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.

GND

ref

OUT

INT/HOLD

XIN

XOUT

CH1P

CH1N

CH1FB

CH2FB

CH2N

CH2P

TEST

SCLK

SDI

SDO

DW PACKAGE

(TOP VIEW)

Summary of content (24 pages)

PAGE 1
SLIS110A − APRIL 2003 − REVISED MAY 2005 features D Dual-Channel Knock Sensor Interface D Programmable Input Frequency Prescaler D D D D D D (OSCIN) Serial Interface With Microprocessor (SPI) Programmable Gain Programmable Band-Pass Filter Center Frequency External Clock Frequencies up to 24 MHz − 4, 5, 6, 8, 10, 12, 16, 20, and 24 MHz Programmable Integrator Time Constants Operating Temperature Range −40°C to 125°C DW PACKAGE (TOP VIEW) VDD GND Vref OUT NC NC INT/HOLD CS XIN X
PAGE 2
SLIS110A − APRIL 2003 − REVISED MAY 2005 functional block diagram Vref VDD/2 + − CH1P + CH1N − Mux CH1FB SAR <1:10> 10-Bit ADC fs = 200 kHz 3rd Order AAF CH2P + CH2N − CH2FB Programmable Band-Pass Filter Programmable Gain Rectifier Programmable Integrator DSP R2R 10-Bit DAC fs = 200 kHz SPI Test Mode DSP Control + − VDD 2 GND OUT SDO SDI POST OFFICE BOX 655303 SCLK CS • DALLAS, TEXAS 75265 TEST INT/HOLD XIN XOUT
PAGE 3
SLIS110A − APRIL 2003 − REVISED MAY 2005 Terminal Functions TERMINAL DESCRIPTION NO.
PAGE 4
SLIS110A − APRIL 2003 − REVISED MAY 2005 absolute maximum ratings over operating free-air temperature (unless otherwise noted)† Regulated input voltage (see Notes 1 and 2), VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 7 V Output voltage (see Notes 1 and 2), VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 7 V Input voltage (see Notes 1 and 2), VIN . . . . . . . . . . . . . . . . . .
PAGE 5
SLIS110A − APRIL 2003 − REVISED MAY 2005 dc electrical characteristics, VDD = 5 V ±5%, input frequency before prescaler = 4 MHz to 20 MHz (±0.
PAGE 6
SLIS110A − APRIL 2003 − REVISED MAY 2005 dc electrical characteristics, VDD = 5 V ±5%, input frequency before prescaler = 4 MHz to 20 MHz (±0.
PAGE 7
SLIS110A − APRIL 2003 − REVISED MAY 2005 ac electrical characteristics, VDD = 5 V ±5%, TA = −40°C to 125°C (unless otherwise specified) DESCRIPTION MIN TYP MAX 5 UNITS fSPI t1 SPI frequency Time from CS falling edge to SCLK rising edge 10 ns t2 Time from CS falling edge to SCLK falling edge 80 ns t3 Time for SCLK to go high 60 ns t4 Time for SCLK to go low 60 ns t5 Time from last SCLK falling edge to CS rising edge 80 ns t6 Time from SDI valid to falling e
PAGE 8
SLIS110A − APRIL 2003 − REVISED MAY 2005 function principle The TPIC8101 is designed for knock sensor signal conditioning in automotive applications. The device is an analog interface between the engine acoustical sensors or accelerometers and the fuel management systems of a gasoline engine. The two wide-band amplifiers process signals from the piezoelectric sensors. Outputs of the amplifiers feed a channel select mux switch and then a 3rd order antialiasing filter.
PAGE 9
SLIS110A − APRIL 2003 − REVISED MAY 2005 description of the functional terminals (continued) oscillator input (XIN) The XIN terminal is the input to the inverter used for the oscillator circuit. An external clock signal from the MCU, crystal, or ceramic resonator is configured with resistors and capacitors. To bias the inverter, a resistor (1 MΩ typ) is placed across XIN and XOUT. This clock signal is prescaled to set the internal sampling frequency of the A/D converter.
PAGE 10
SLIS110A − APRIL 2003 − REVISED MAY 2005 R2 C CH1N − R1 Knock Sensor 1 CH1P + CH1FB + CH2FB Vref CH2P C R1 − CH2N Knock Sensor 2 R2 NOTE: The series capacitor C is not mandatory and may be removed in some application circuits. Figure 2. Input Signal Configuration Table 1. Integrator Programming DECIMAL VALUE (D4…D0) INTEGRATOR TIME CONSTANT (µSEC) BAND-PASS FREQUENCY (kHz) 0 40 1 45 2 3 10 GAIN DECIMAL VALUE (D5…D0) BAND-PASS FREQUENCY (kHz) GAIN 1.
PAGE 11
SLIS110A − APRIL 2003 − REVISED MAY 2005 Table 1. Integrator Programming (Continued) DECIMAL VALUE (D4…D0) INTEGRATOR TIME CONSTANT (µSEC) BAND-PASS FREQUENCY (kHz) GAIN DECIMAL VALUE (D5…D0) BAND-PASS FREQUENCY (kHz) GAIN 24 320 25 360 3.28 0.63 56 13.72 0.148 3.43 0.607 57 14.36 0.143 26 27 400 3.59 0.586 58 15.07 0.138 440 3.76 0.567 59 15.84 0.133 28 480 3.95 0.548 60 16.71 0.129 29 520 4.16 0.5 61 17.67 0.125 30 560 4.39 0.
PAGE 12
SLIS110A − APRIL 2003 − REVISED MAY 2005 PRINCIPLES OF OPERATION system transfer equation The output voltage may be derived from: V O +V t IN A IN A A P BP A INT INT t C A O )V RESET where: VIN = Input voltage peak (amplitude) VO = Output voltage AIN = Input amplifier gain setting AP = Programmable gain setting ABP = Gain of band-pass filter AINT = Gain of integrator tINT = Integration time from 0.
PAGE 13
SLIS110A − APRIL 2003 − REVISED MAY 2005 PRINCIPLES OF OPERATION Table 2. Default SPI Mode NO.
PAGE 14
SLIS110A − APRIL 2003 − REVISED MAY 2005 PRINCIPLES OF OPERATION Table 3. Advanced SPI Mode NO.
PAGE 15
SLIS110A − APRIL 2003 − REVISED MAY 2005 programming examples prescaler/SDO status D 01000101 programs an input frequency of 6 MHz with SDO terminal in high impedance. channel selection D 1110001 selects channel 2. band-pass frequency D 00100111 programs a band-pass filter with center frequency of 6.37 kHz. gain control D 10010100 programs the gain with attenuation of 0.739. integrator time constant D 11000011 programs integrator time constant of 55 µs.
PAGE 16
SLIS110A − APRIL 2003 − REVISED MAY 2005 TYPICAL CHARACTERISTICS Input Signal Int/Hold Signal Output Signal Figure 3. Amplified Input Signal Process Input Signal Int/Hold Signal Output Signal Figure 4.
PAGE 17
SLIS110A − APRIL 2003 − REVISED MAY 2005 application schematic VDD OUT 4.7 µF A/D R2 CH1FB 3.3 nF CS CH1N SCLK R1 Knock Sensor 1 TPIC8101 CH1P SDI SDO Microprocessor TEST Vref 100 nF CH2P INT/HOLD R2 CH2FB 3.3 nF 470 pF XIN CH2N 1 kΩ XOUT 1 MΩ R1 Knock Sensor 2 GND NOTE: R1 is greater than 25 kΩ.
PAGE 18
PACKAGE OPTION ADDENDUM www.ti.
PAGE 19
PACKAGE OPTION ADDENDUM www.ti.com 10-Nov-2013 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
PAGE 20
PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPIC8101DWR Package Package Pins Type Drawing SOIC DW 20 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 24.4 Pack Materials-Page 1 10.8 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 13.3 2.7 12.0 24.
PAGE 21
PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPIC8101DWR SOIC DW 20 2000 367.0 367.0 45.
PAGE 22
PAGE 23
PAGE 24
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.