TLE4470 Siemens Semiconductor Group, TLE4470 Datasheet - Page 14

• Manufacturer Part Number: TLE4470
• Description: Dual Low-Drop Voltage Regulator
• Manufacturer: Siemens Semiconductor Group

Input, Output
The input capacitor
approx. 1
be damped. To stabilize the regulation circuits of the stand-by and main regulator, output
capacitors
C
For the TLE 4470 G (P-DSO-20-6) the output voltage
adjusted to 5 V
adjust pin VA. For
main output.
For calculating
Definitions:
Disable
The main regulator of the TLE 4470 can be switched OFF by a voltage of 2.3 V at pin
DIS. Reducing this voltage below 1.4 V will switch ON the main regulator again.
Reset Timing
The power-on reset delay time is defined by the charging time of an external capacitor
C
Definitions:
The reset reaction time
LOW after the output voltage has dropped below the reset threshold. It is typically 2 s
for delay capacitor of 100 nF. For other values for
using the following equation:
Semiconductor Group
Q2
d
which can be calculated as follows:
10 F, both with an ESR
C
in series with
Q1
R
V
C
I
V
d
V
t
V =
and
ref
dt
d
d
Q
V
=
= Output voltage of stand by regulator, typical 5 V
= delay capacitor
= delay time
= charge current, typical 5 A
= upper delay switching threshold at
or
Q2rated
V
C
C
R
V
Q2
R
I
1
dt
Q2
is necessary for compensating line influences. Using a resistor of
1
, typical 1.8 V
= 5 V the voltage adjust pin has to be connected directly to the
//
&
t
are necessary. Stability is guaranteed at values
R
rr
C
R
2
20 V by connecting an external voltage divider to the voltage
is the time it takes the voltage regulator to set the reset out
2
I
, the LC circuit of input inductivity and input capacitance can
;
respectively the following equations can be used:
R
V
10
R
Q
C
R
2
=
100 k
t
=
1
d
rr
V
=
= (
R R
ref
within the operating temperature range.
R
20 s/F
t
d
14
(
or
R
(
1
V
1
/ (
I
Q
+
d
R
) / V
/
R
1
V
C
2
C
–
ref
) /
d
d
R
)
the reaction time can be estimated
R
)
V
2
C
Q2
d
for reset delay time
of the main regulator can be
C
Q1
TLE 4470
1998-11-01
6 F &