U5020M-FP TEMIC [TEMIC Semiconductors], U5020M-FP Datasheet - Page 2

• Manufacturer Part Number: U5020M-FP
• Description: Digital Window Watchdog Timer
• Manufacturer: TEMIC [TEMIC Semiconductors]

Pin Description
Functional Description
Supply, Pin 13
The U5020M requires a stabilized supply voltage
V
characteristic.
An external buffer capacitor of C = 10 nF may be
connected between Pin 13 and GND.
RC-Oscillator, Pin 15
The clock frequency, f, can be adjusted with the
components R
U5020M
2 (8)
DD
Wake-up
Wake-up
Wake-up
Wake-up
Wake-up
Wake-up
= 5 V
TM
TM
"
1
1
3
5
8
2
4
6
7
and C
5% to comply with its electrical
Figure 2. Pin connections
1
according to the formula:
95 10635
Preliminary Information
16
15
14
13
12
11
10
9
t
Osc
GND
V
Mode
Trig
Reset
Ena
s
DD
where t
The clock frequency determines all time periods of the
logic part as shown in the last section of the data sheet
(timing). With an appropriate selection of components,
the clock frequency, f, is nearly independent of the supply
voltage as shown in figure 3. Frequency tolerance
D
3 to 8 Wake-up Wake-up inputs (pull-down
f
Pin
max
10
11
12
13
14
15
16
1
2
9
= 10% with R
f
R
+
+
1
Symbol
in k
Mode
Reset
GND
V
1
Trig
1.35
TM
TM
Ena
Osc
t
t
DD
s
W
, C
)
Test must not be connected
Test must be connected to GND
resistor)
There are six digitally debounced
wake-up inputs. During the long
trigger mode each signal slope at
the inputs initiates a reset pulse at
Pin 10.
Enable output (push-pull)
It is used for the control of periph-
eral components. It is activated
after the processor triggers three
times correctly.
Reset output (open drain)
Resets the processor in the case of
a trigger error or if a wake-up
pulse occurs during the long
watchdog period.
Trigger input (pull-up resistor)
It is connected to the microproces-
sor’s trigger signal.
Mode input (pull-up resistor)
The processor’s mode signal initi-
ates the switchover between the
long and the short watchdog time.
Supply voltage
Ground, reference voltage
RC oscillator
Time switch input
Programming pin to select differ-
ent time durations for the long
watchdog time.
1
1.57 R
1
"
TELEFUNKEN Semiconductors
in nF and t in
1%, C
1
(C
1
1
Function
)
=
"
Rev. A3, 27-Feb-97
0.01)
m
5%.
s