L9918 datasheet(15/109 Pages) STMICROELECTRONICS

15 / 109 page

Symbol

Parameter

Notes

Min.

Typ.

Max.

Unit

VLOW,7

Low-Voltage threshold

(U_FELD_EIN)

10.75

11.25

VLOW,8

VLOW = 9.9 V + 0.388 * (VSET -

10.6 V)

PSA

VB+_LIM

Set point limit threshold

VBLVft,1

Bidirectional Low-voltage filter

time (U_FELD_EIN_TIME)

529

µs

VBLVft,2

780

µs

VBLVft,3

1040

µs

VBLVft,4

1200

µs

VBPOR

Power On Reset when is elapsed

at least td time

2.7

Max battery interruption time

µs

Minimum time between two

battery interruptions

2.2

B+ characteristics

2.2.1

Set point value correction

It is possible for the customer at end of line to perform a set-point voltage value correction by dedicated NVM bits

(UR_OFFSET). The set-point voltage value can be adjusted from - 200 mV to 150 mV with steps of 50 mV. Such

voltage correction applies both to default set point (VBSPDEF) and LIN set point (VBSPLINRG).

2.2.2

Voltage regulation loop

Regulation loop circuit is composed by two main blocks: direct (or proportional) control block and feedback (or

deviation) control block.

Direct or proportional control applies an EXC DC correction which directly depends on the calculated error (which

is obtained as B+ - VBSPLINRG/VBSPDEF).

Proportional control can be selected by P_ANT NVM bits. Small values of P_ANT correspond to a high regulation

sensitivity.

Figure 6 (P_ANT regulation) reports the output voltage (B+) variation depending in the EXC DC in case only

proportional regulation is used.

Feedback (or deviation) control is a set point correction which depends on EXC DC.

Such correction shall be used in order to compensate eventual voltage drop occurring between car battery and

car loads and regulator B+.

Feedback control options can be selected by I_ANT NVM bits. High values of I_ANT correspond to a high offset

on the adopted set point. I_ANT offset is applied after a filter time selectable by I_FILT NVM bits.

Figure 6 (I_ANT variation) reports the dependency between EXC DC and B+ for various I_ANT settings.

L9918

B+ characteristics

DS13000 - Rev 2

page 15/109

L9918 датащи(PDF) 15 Page - STMicroelectronics

L9918 датащи(HTML) 15 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL