L4989 Datasheet, PDF (2/10 Pages) STMicroelectronics – LOW POWER VOLTAGE REGULATOR

L4989
PIN DESCRIPTION
N. (SO8)
N. (SO20)
1
1
2
4
5,6,15,16
3
7
4
10
5
11
6
14
7
17
8
20
2,3,8,9,12,
13,18,19
PIN CONNECTIONS
NAME
WEn
gnd
gnd
Res
Vcr
Vcw
Wi
Vo
Vs
N. C.
FUNCTION
Watchdog enable input.
If high it activates the watchdog operation.
Ground reference
Ground
Connected these pins to a heat spreader ground
Reset output.
It is pulled down when output voltage goes below Vo_th or
frequency at Wi is too low.
Reset timing adjust.
A capacitor between Vcr pin and gnd, sets the reset delay time
(trd)
Watchdog timer adjust
A capacitor between Vcw pin and gnd, sets the time response of
the watchdog monitor.
Watchdog input.
If the frequency at this input pin is too low, the Reset output is
activated.
Voltage regulator output
Block to ground with a capacitor >100nF (needed for regulator
stability)
Supply voltage
Block to ground directly at IC pin with a ceramic capacitor
not connected
VEN
GND
RES
VCR
1
8
2
7
3
6
4
5
D04AT515
SO8
V_S
V_O
WI
VCW
VEN
N.C.
N.C.
GND
GND
GND
RES
N.C.
N.C.
VCR
1
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
D04AT516
SO20
V_S
N.C.
N.C.
V_O
GND
GND
WI
N.C.
N.C.
WCW
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