L4993 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L4993' PDF : 30 Pages View PDF
Block diagram and pins description
L4993
Table 2.
Pin
name
WEn
Gnd
Gnd
Res
Vcr
Vcw
Wi
Vos
Vs
N.C.
Pins description
SO-8 (D) SO-20 (MD)
Function
Watchdog Enable input
1
1
If high watchdog functionality is active
2
4
Ground reference
Ground
5, 6, 15, 16
Connected these pins to a heat spreader ground
Reset output.
3
7
It is pulled down when output voltage goes below Vo_th
or frequency at Wi is too low.
Leave floating if not used.
Reset timing adjust.
4
10
A capacitor between Vcr pin and gnd, sets the reset
delay time (trd)
Watchdog timer adjust
5
11
A capacitor between Vcw pin and gnd, sets the time
response of the watchdog monitor.
Watchdog input.
6
14
If the frequency at this input pin is too low, the Reset
output is activated.
Connect to ground if not used
Voltage regulator output
7
17
Block to ground with a capacitor >100nF (needed for
regulator stability)
Supply voltage
8
20
Block to ground directly at IC pin with a capacitor
2, 3, 8, 9, 12,
13, 18, 19
Not connected
Figure 2. Pins configuration
WEn
GND
Res
Vcr
1
8
2
SO-8 7
3
6
4
5
Vs
Vos
Wi
Vcw
WEn
N.C.
N.C.
GND
GND
GND
Res
N.C.
N.C.
Vcr
1
20
2
19
3
18
4
17
5 SO-20 16
6
15
7
14
8
13
9
12
10
11
Vs
N.C.
N.C.
Vos
GND
GND
Wi
N.C.
N.C.
Vcw
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