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Product data sheet

Rev. 05 — 28 June 2005

3 of 16

Philips Semiconductors

TDA3661

Very low dropout voltage/quiescent current voltage regulator

6.2 Pin description

[1]

All GND pins are connected to the lead frame and can also be used to reduce the total thermal resistance

board acts like a heat spreader.

7.

Functional description

The TDA3661 is an adjustable voltage regulator with an output voltage that can be fixed

by means of an external resistor divider. The regulator can deliver output currents up to

100 mA. The regulator is available in an SO8 package. The regulator is intended for

portable, mains and telephone applications. To increase the lifetime of batteries, a

specially built-in clamp circuit keeps the quiescent current of this regulator very low, in

dropout and full load conditions.

The device remains operational down to very low supply voltages (typical 2 V) and below

this voltage it switches off. A temperature protection is included which switches off the

regulator output at a junction temperature above 150

°C.

8.

Limiting values

9.

Thermal characteristics

Table 3:

Pin description

Symbol

Pin

Description

REG

1

regulator output

GND

2, 3, 6 and 7

ground [1]

n.c.

4

not connected

ADJ

5

feedback input

8

supply voltage

Table 4:

Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol

Parameter

Conditions

Min

Max

Unit

supply voltage

-

45

V

reverse polarity supply

voltage

non-operating

-

−25

V

total power dissipation

temperature of

copper area is

25

°C

-

4.1

W

storage temperature

non-operating

−55

+150

°C

ambient temperature

operating

−40

+125

°C

junction temperature

operating

−40

+150

°C

Table 5:

Thermal characteristics

Symbol

Parameter

Conditions

Typ

Unit

thermal resistance from junction to case

to center pins; soldered

30

K/W

thermal resistance from junction to ambient

in free air; soldered

155

K/W