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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.

(1) C1 is optional (to minimize supply noise only)

(2) C2

≤ 4700 µF

Fig 3.

Application circuit with backup function

mgs582

VP

81

2, 3, 6, 7

5

TDA3661

75.1 k

Ω

1

µF

R1

24.9 k

Ω

R2

= 5 V

C1 is optional (to minimize supply noise only)

Fig 4.

Application circuit with enable function

mgs583

VP

81

2, 3, 6, 7

enable

C2

5

TDA3661

75.1 k

Ω

10

µF

1

µF

R1

24.9 k

Ω

R2

D1

= 5 V