L9918 datasheet(23/109 Pages) STMICROELECTRONICS

номер детали	L9918

подробное описание детали	Alternator voltage regulator with LIN interface for 12 V applications

PDF	109 Pages

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производитель	STMICROELECTRONICS [STMicroelectronics]

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Figure 10. PH frequency calculation using adaptive PH thresholds calculation

High adaptive

threshold

Low adaptive

threshold

Signal after comparators

(used for PH frequency calculation)

VPadth_HT

NVM parameters for Adaptive PH thresholds control are: ACADAPMIN_MODE, KLV_AC_ADAP_MAX,

KLV_AC_ADAP_MIN and AC_ADAP_M_BAND. Parameters descriptions are reported into Section A.1 NVM

parameters table

A further usage of the adaptive PH threshold calculation regards the hot start function activation: one of hot start

activation conditions requires Adaptive PH mean value to be greater than VPadth _HT.

A more detailed description of the hot start function can be found into Section 3.2.4 Hot start.

3.2.4

Hot start

Hot start is a particular function which leads device into Regulation default state from Wake up state.

Hot start is activated when the all the three following conditions are verified:

•

Phase signal is present on PH pin within 53ms after a wakeup event (Section 1.5.1 Standby).

•

Engine rotation is N > Nstart.

•

Adaptive PH threshold mean is greater than VPadth _HT or PH signal crosses phase regulation thresholds

(VPHThREG,x threshold and eventually VPLTh if KLV_HED_DIS = 0).

Please note that in case all conditions for Hot Start are met, L9918 however needs a latency time before starting

the regulation. This is the time needed to properly evaluate phase signal frequency and it can be programmed by

PRG_EVENTFILT_5_3 NVM register.

L9918

PH characteristics

DS13000 - Rev 2

page 23/109

L9918 датащи(PDF) 23 Page - STMicroelectronics