TLE42994V33 Datasheet, PDF (15/25 Pages) Infineon Technologies AG – Low Dropout Fixed Voltage Regulator

TLE42994V33
Block Description and Electrical Characteristics
Reset Reaction Time:
The reset reaction time avoids that short undervoltage spikes trigger an unwanted reset “low” signal. The reset
reaction rime t_rr considers the internal reaction time t_rr,int and the discharge time t_rr,d defined by the external delay
capacitor C_D (see typical performance graph for details). Hence, the total reset reaction time becomes:
t_rr = t_{rd, int} + t_{rr, d}
with
• t_rr: reset reaction time
• t_rr,int: internal reset reaction time
• t_rr,d: reset discharge
Optional Reset Output Pull-Up Resistor R_RO,ext:
The Reset Output RO is an open collector output with an integrated pull-up resistor. If needed, an external pull-up
resistor to the output Q can be added. In Table “Electrical Characteristics Reset Function” on Page 18 a
minimum value for the external resistor R_RO,ext is given.
Reset Adjust Function
The undervoltage reset switching threshold can be adjusted according to the application’s needs by connecting
an external voltage divider (R_ADJ1, R_ADJ2) at pin RADJ. For selecting the default threshold connect pin RADJ to
GND.
When dimensioning the voltage divider, take into consideration that there will be an additional current constantly
flowing through the resistors.
With a voltage divider connected, the reset switching threshold V_RT,new is calculated as follows:
V_{RT, new}
=
R-----_{A---D----J--,--1----}+_{-----R----A----D----J--,--2-}
R_{ADJ, 2}
×
V _{R A D J,}
th
with
• V_RT,new: the desired new reset switching threshold
• R_ADJ1, R_ADJ2: resistors of the external voltage divider
• V_RADJ,th: reset adjust switching threshold given in Table “Electrical Characteristics Reset Function” on
Page 18
Data Sheet
15
Rev. 1.01, 2010-10-14