TDA3674AT PHILIPS [NXP Semiconductors], TDA3674AT Datasheet - Page 7

• Manufacturer Part Number: TDA3674AT
• Description: Low dropout voltage/quiescent current 5 V voltage regulator with enable
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
E
The regulator is stabilized with an electrolytic capacitor of
68 F (ESR = 0.5 ). At T
value is decreased to 22 F and the ESR is increased
to 3.5 . The regulator will remain stable at a temperature
of T
E
The regulator is stabilized with an electrolytic capacitor of
10 F (ESR = 3.3 ). At T
value is decreased to 3 F and the ESR is increased to
20 . The regulator will remain stable at a temperature of
T
E
The regulator is stabilized with a 100 nF MKT capacitor
connected to the output. Full stability is guaranteed when
the output current is larger then 200 A. Because the
thermal influence on this capacitor value is almost zero,
the regulator will remain stable at a temperature of
T
E
The regulator is stabilized with a 100 nF capacitor in
parallel with a electrolytic capacitor of 10 F connected to
the output.
The regulator is now stable under all conditions and
independent of:
Application circuits
The maximum output current of the regulator equals:
When T
current equals 140 mA.
For successful operation of the IC (maximum output
current capability) special attention has to be given to the
copper area required as heatsink (connected to all
GND pins), the thermal capacity of the heatsink and its
ability to transfer heat to the external environment. It is
2000 Feb 01
I
REG max
amb
amb
XAMPLE
XAMPLE
XAMPLE
XAMPLE
The ESR of the electrolytic capacitor
The value of the electrolytic capacitor
The output current.
Low dropout voltage/quiescent current 5 V
voltage regulator with enable
amb
= 40 C.
= 40 C.
= 40 C.
amb
1
2
3
4
=
=
= 21 C and V
------------------------------------ - (mA)
100
------------------------------------------------------ -
R
150 T
th(j-a)
150 T
–
V
P
amb
–
V
–
P
5
amb
amb
amb
P
–
= 14 V, the maximum output
V
REG
= 40 C, the capacitor
= 40 C, the capacitor
7
handbook, halfpage
possible to reduce the total thermal resistance from
120 to 50 K/W.
A
Sometimes a backup function is needed to supply, for
example, a microcontroller for a short period of time when
the supply voltage spikes to 0 V (or even 1 V).
This function can easily be built with the TDA3674 by using
an output capacitor with a large value. When the supply
voltage is 0 V (or 1 V), only a small current will flow into
pin REG from this output capacitor (a few A).
The application circuit is given in Fig.6.
PPLICATION CIRCUIT WITH BACKUP FUNCTION
V
(1) C1 is optional (to minimize supply noise only).
(2) C2
I(EN)
Fig.6 Application circuit with backup function.
V I(EN)
= 5 V.
V P
4700 F.
C1
1 F
(1)
8
5
TDA3674
2, 3, 6, 7
1
MGS600
Preliminary specification
C2
(2)
TDA3674
V REG = 5 V