Philips Semiconductors
TDA3663
Very low dropout voltage/quiescent current 3.3 V voltage regulator
11.3.1 Application circuit with backup function
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 TDA3663 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 µA).
The application circuit is given in Figure 4.
VP
C1(1)
1 µF
1
3
TDA3663
VREG = 3.3 V
C2(2)
2, 4
mgs587
(1) C1 is optional (to minimize supply noise only).
(2) C2 ≤ 4700 µF.
Fig 4. Application circuit with backup function (SO4 version)
9397 750 15047
Product data sheet
Rev. 05 — 13 June 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
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