Datasheet

9397 750 15049 © Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet Rev. 05 — 28 June 2005 6 of 16
Philips Semiconductors
TDA3661
Very low dropout voltage/quiescent current voltage regulator
11.3.2 Application circuit with enable function
An enable function can easily be built with the TDA3661 by connecting a diode to pin ADJ.
When the voltage on pin ADJ is forced above 1.3 V, the output will switch off. The standby
current is equal to the quiescent current of the TDA3661.
The application circuit is given in Figure 4.
11.4 Additional application information
This section gives typical curves for various parameters measured on the TDA3661AT.
Standard test conditions are: V
P
= 14.4 V, T
amb
=25°C and k = 4.01929.
(1) C1 is optional (to minimize supply noise only)
(2) C2 ≤ 4700 µF
Fig 3. Application circuit with backup function
mgs582
V
P
81
2, 3, 6, 7
C2
(2)
5
TDA3661
75.1 kΩ
C1
(1)
1 µF
R1
24.9 kΩ
R2
V
REG
= 5 V
C1 is optional (to minimize supply noise only)
Fig 4. Application circuit with enable function
mgs583
V
P
81
2, 3, 6, 7
enable
C2
5
TDA3661
75.1 kΩ
10 µF
C1
(1)
1 µF
R1
24.9 kΩ
R2
D1
V
REG
= 5 V