DS8714 Rev 3

9/19

L4989D, L4989MD

Electrical specifications

18

Table 6. Reset

Pin

Symbol

Parameter

Test condition

Min.

Typ.

Max.

Unit

Res

Vres_l

Reset output low voltage

Rext = 5 k to Vo;

Vo > 1 V

0.4

V

Res

IRes_lkg

Reset output high leakage

current

VRes = 5 V

1

µA

Res

RRes

Pull up internal resistance

Versus Vo

10

20

50

k



Res

Vo_th

Reset threshold voltage

VS = 5.6 to 31 V;

Io = 1 to 150 mA

6%

8%

10%

Below

Vo_ref

Vcr

Vrlth

Reset timing low threshold

VS = 13.5 V

10%

13%

16%

Vo_ref

Vcr

Vrhth

Reset timing high threshold

VS = 13.5 V

44%

47%

50%

Vo_ref

Vcr

Icr

Charge current

VS = 13.5 V

8

15

30

µA

Vcr

Idr

Discharge current

VS = 13.5 V

8

15

30

µA

Res

Trr_2

Reset reaction time(1)

Vo = Vo_th -100 mV

100

250

700

µs

Res

Trd

Reset delay time

VS = 13.5 V;

Ctr = 1 nF

65

115

165

ms

1. When Vo becomes lower than 4 V, the reset reaction time decreases down to 2 µs assuring a faster reset condition in this

particular case.

Table 7. Watchdog

Pin

Symbol

Parameter

Test condition

Min.

Typ.

Max.

Unit

Wi

Vih

Input high voltage

VS = 13.5 V

3.5

V

Wi

Vil

Input low voltage

VS = 13.5 V

1.5

V

Wi

Vih

Input hysteresis

VS = 13.5 V

500

mV

Wi

Rwi

Pull down resistor

VS = 13.5 V

30

100

250

K



Vcw

Vwhth

High threshold

VS = 13.5 V

44%

47%

50%

Vo_ref

Vcw

Vwlth

Low threshold

VS = 13.5 V

10%

13%

16%

Vo_ref

Vcw

Icwc

Charge current

VS = 13.5 V;

Vcw = 0.1 V

510

20

µA

Vcw

Icwd

Discharge current

VS = 13.5 V;

Vcw = 2.5 V

1.25

2.5

5

µA

Vcw

Twop

Watchdog period

VS = 13.5 V;

Ctw = 47 nF

20

40

80

ms

Res

twol

Watchdog output low time

VS = 13.5 V;

Ctw = 47 nF

48

16

ms