TLE6365_07 Datasheet, PDF (9/18 Pages) Infineon Technologies AG – Step Down Voltage Regulator with Reset

TLE 6365
Circuit Description
Below some important sections of the TLE 6365 are described in more detail.
Power On Reset
In order to avoid any system failure, a sequence of several conditions has to be passed.
In case of V_CC power down (V_CC < V_RT for t > t_RR) a logic LOW signal is generated at the
pin RO to reset an external microcontroller. When the level of V_CC reaches the reset
threshold V_RT, the signal at RO remains LOW for the Power-up reset delay time t_RD
before switching to HIGH. If V_CC drops below the reset threshold V_RT for a time extending
the reset reaction time t_RR, the reset circuit is activated and a power down sequence of
period t_RD is initiated. The reset reaction time t_RR avoids wrong triggering caused by short
“glitches” on the V_CC-line.
V_CC
Typ. 4.70 V
V_{PG Typ. 4.65 V}
V_RT
1V
Start Up ON Delay
< t_RR
RO
H
Invalid
L
Power Start-Up
t_RD
t_RR
Normal
ON Delay
Started
Invalid
Failed
< t_RD
ON Delay
t
Stopped
Invalid
N
Failed
t
t_RD
Normal
AET03325.VSD
Figure 3 Reset Function
Data Sheet
9
Rev. 1.9, 2007-07-30