L4989 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L4989' PDF : 19 Pages View PDF
L4989
Electrical specifications
Table 6. Reset
Pin Symbol
Parameter
Test condition Min. Typ. Max. Unit
Res
Vres_l Reset output low voltage Rext = 5kΩ to Vo,
Vo > 1V
0.4 V
Res
IRes_lkg
Reset output high leakage
current
VRes = 5V
1 µA
Res
RRes Pull up internal resistance Versus Vo
10 20 40 kΩ
Res
Vo_th Reset threshold voltage
Vs = 5.6 to 31V,
Io = 1 to 150mA
6%
8%
10%
Below
Vo_ref
Vcr
Vrlth Reset timing low threshold Vs = 13.5V
10% 13% 16% Vo_ref
Vcr
Vrhth Reset timing high threshold Vs =13.5V
44% 47% 50% Vo_ref
Vcr
Icr
Charge current
Vs = 13.5V
8 15 30 µA
Vcr
Idr
Discharge current
Vs = 13.5V
8 15 30 µA
Res
Trr_2 Reset reaction time(1)
t(s) Res
Trd Reset delay time
Vo = Vo_th -100mV 100 250 700 µs
Vs = 13.5V,
Ctr = 1nF
65 115 165 ms
uc 1. When Vo becomes lower than 4V, the reset reaction time decreases down to 2µs assuring a faster reset
d condition in this particular case.
Pro Table 7. Watchdog
te Pin Symbol
Parameter
le Wi
Vih Input high voltage
so Wi
Vil
Input low voltage
Ob Wi
Vih Input hysteresis
- Wi
Rwi Pull down resistor
t(s) Vcw
Vwhth High threshold
c Vcw
Vwlth Low threshold
du Vcw
Icwc Charge current
Pro Vcw
Icwd Discharge current
leteVcw
Twop Watchdog period
Obso Res
twol Watchdog output low time
Test condition
Vs = 13.5V
Vs = 13.5V
Vs = 13.5V
Vs = 13.5V
Vs = 13.5V
Vs = 13.5V
Vs = 13.5V,
Vcw = 0.1V
Vs = 13.5V,
Vcw = 2.5V
Vs = 13.5V,
Ctw = 47nF
Vs = 13.5V,
Ctw = 47nF
Min. Typ. Max. Unit
3.5
V
1.5 V
500
mV
30 100 250 KΩ
44% 47% 50% Vo_ref
10% 13% 16% Vo_ref
5 10 20 µA
1.25 2.5 5 µA
20 40 80 ms
4
8 16 ms
9/19
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