TLE4291E Infineon Technologies, TLE4291E Datasheet - Page 22

• Manufacturer Part Number: TLE4291E
• Manufacturer: Infineon Technologies

Specifications of TLE4291E

• Packages: PG-SSOP-14
• Regulator Type: single output
• Output Voltage: 5V
• Accuracy: 2.0 %
• Max. Output Current: 450mA
• Dropout Voltage: 250mV

9
9.1
The TLE4291 features a programmable watchdog timing.
The watchdog function monitors a microcontroller, including time base failures. In case of a missing rising edge
within a certain pulse repetition time, the watchdog output is set to ‘low’. The programming of the expected
watchdog pulse repetition time can be easily done by an external reset delay capacitor.
The watchdog output “WO” is separated from the reset output “RO”. Hence, the watchdog output might be used
as an interrupt signal for the microcontroller independent from the reset signal. It is possible to interconnect pin
“WO” and pin “RO” in order to establish a wire-or function with a dominant low signal.
Figure 8
Watchdog Output “WO”
The watchdog output “WO” is an open collector output with an integrated pull-up resistor. In case a lower-ohmic
“WO” signal is desired, an external pull-up resistor to the output “Q” can be connected. Since the maximum “WO”
sink current is limited, the optional external resistor
sink current (see
Watchdog Input “WI”
The watchdog is triggered by an positive edge at the watchdog input “WI”. The signal is filtered by a bandpass
filter and therefore its amplitude and slope has to comply with the specification
details on the test pulse applied, see
Data Sheet
Supply
I
WI
Watchdog Function
Description
Block Diagram Watchdog Circuit
Detect
Edge
Item 9.2.8
GND
Control
OR
and
Item
S
R
1
Figure
Supply
9.2.9).
V
Int.
DW,hi
9.
I
I
D,ch
DW,dsch
R
WO,ext
22
needs to be sized to comply with the watchdog output
V
DW
D
C
D
BlockDiagram_ Watchdog .vsd
R
WO
WO
Item 9.2.11
Q
I
WO
C
WI
Rev. 1.0, 2011-06-07
Watchdog Function
Q
to
Item
I
Q
TLE4291
9.2.15. For
Controller
VDD
Reset
I/O
Micro-
GND