L9177 datasheet(39/49 Pages) STMICROELECTRONICS

부품명	L9177

상세설명	Peripheral on chip for low end engine control

PDF	49 Pages

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제조업체	STMICROELECTRONICS [STMicroelectronics]

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L9177

Functional description

4.6.2

Auto-adaptative hysteresis

Input signals difference is obtained trough a full differential amplifier; its output, DV signal, is

fed to peak detection circuit and then to A/D converter implemented with 4 voltage

comparator (5 levels Pvi).Output of A/D is sent to Logic block (hysteresis selection Table 33)

that implements correlation function between Peak voltage and hysteresis value; hysteresis

value is used by square filtering circuit which conditions DV signal.

Figure 30. Auto-adaptive hysteresis block diagram

Figure 31. Hysteresis output voltage level

To the previous 5 levels PV = [0 PV1 PV2 PV3 PV4] correspond a set of 5 thresholds:



H = [HO HIH2 H3 H4]

The advised values for the previous defined vectors are:



PV = [0 PV1 PV2 PV3 PV4] = [0, 900, 1560, 2230, 2900] mV



H = [H0 H1 H2 H3 H4] = [100, 200, 350, 650, 1000] mV

L9177 데이터시트(PDF) 39 Page - STMicroelectronics