TDA3664_7

© NXP B.V. 2007. All rights reserved.

Product data sheet

Rev. 07 — 25 June 2007

7 of 16

NXP Semiconductors

TDA3664

Very low dropout voltage/quiescent current 5 V voltage regulator

Remark: In the event of using different types of capacitors, a minimum ESR needs to

be created by using an additional resistor that is placed in series with the output

capacitor, see Figure 4.

margin.

11.3 Application circuits

The maximum output current of the regulator equals:

The total thermal resistance of the TDA3664 (SOT223-1 package) can be decreased to

lower values when pin 4 and body of the package are soldered to the printed-circuit board.

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 TDA3664 by using a large output capacitor. When

the supply voltage is 0 V (or

−1 V), only a small current will flow into pin REG from this

large output capacitor (a few

µA).

The application circuit is given in Figure 4.

Table 8:

Minimum ESR values required

C2 = 100 nF

C2=1

µF

C2=10

µF

C2 = 100

µF

1> 0

Ω

> 1.5

Ω

> 2.5

Ω

>0

Ω

5> 1

Ω

> 0.5

Ω

>1

Ω

>0

Ω

10

> 0

Ω

> 0.5

Ω

>4

Ω

>0

Ω

100

> 0

Ω

> 0.5

Ω

>4

Ω

>0

Ω

I

REG max

()

150

T

amb

–

R

th j

a

–

()

V

P

V

REG

–

()

×

----------------------------------------------------------

150

T

amb

–

100

V

P

5

–

()

×

------------------------------------ mA

()

==

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

(2) C2

≤ 4700 µF

(4) For reliable operation, it is recommended to have a minimum ESR of 3

Ω of the output

capacitor total (see Figure 4 above) and to have a stable application independent of load

current, temperature or output capacitance.

Fig 4.

Application circuit with backup function (SO4 version)

014aaa089

13

2, 4

C1(1)

1

µF

C2(2)

TDA3664