2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

FEATURES

General

Extremely low noise behaviour and good stability with
very small output capacitors

Second supply pin for regulators 3 and 4 to reduce
power dissipation (e.g. via a DC-to-DC converter)

Three V

-state controlled regulators (regulators 1, 3

and 4) and a power switch

Regulator 2, reset and ignition buffer operational during
load dump and thermal shutdown

Combined control pin for switching regulators 1 and 3

Separate control pins for switching regulator 4 and the
power switch

Supply voltage range from

18 V to +50 V

Low quiescent current in standby mode (when
regulators 1, 3 and 4 and power switch are switched off
and ignition input is low)

Hold output for low V

, load dump and temperature

protection

Reset (push-pull output stage) for regulator 2 and hold
output (open-collector output)

Adjustable reset delay time

High supply voltage ripple rejection

Backup capacitor for regulator 2

One independent ignition buffer (active HIGH).

Protections

Reverse polarity safe (down to

18 V without high

reverse current)

Able to withstand voltages up to 18 V at the outputs
(supply line may be short-circuited)

ESD protection on all pins

Thermal protections

Load dump protection

Foldback current limit protection for regulators 1, 2, 3
and 4

Delayed second current limit protection for the power
switch (at short circuit)

The regulator outputs and the power switch are
DC short-circuit safe to ground and supply (V

GENERAL DESCRIPTION

The TDA3681A is a multiple output voltage regulator with
a power switch and an ignition buffer. It is intended for use
in car radios with or without a microcontroller.
The TDA3681A contains the following:

Four fixed voltage regulators with a foldback current
protection (regulators 1, 2, 3 and 4). Regulator 2, which
is intended to supply a microcontroller, also operates
during load dump and thermal shutdown

Regulators 3 and 4 have a second supply pin that can
be connected to a lower supply voltage (> 6.5 V) to
reduce the power dissipation

A power switch with protection, operated by a control
input

Reset and hold outputs that can be used to interface
with the microcontroller; the reset signal can be used to
call up the microcontroller

Both supply pins can withstand load dump pulses and
negative supply voltages

Regulator 2, which is in regulation at a backup voltage
above 6.5 V

A provision for the use of a reserve supply capacitor that
will hold enough energy for regulator 2 (5 V continuous)
to allow a microcontroller to prepare for loss of voltage

An ignition input Schmitt trigger with push-pull output
stage.

ORDERING INFORMATION

TYPE

NUMBER

PACKAGE

NAME

DESCRIPTION

VERSION

TDA3681ATH

HSOP20

plastic, heatsink small outline package; 20 leads; low stand-off height

SOT418-3

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

QUICK REFERENCE DATA

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

Supplies

supply voltage 1

operating

9.5

14.4

reverse polarity

non-operating

regulator 2 on

14.4

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

supply voltage 2

operating

6.5

14.4

reverse polarity

non-operating

regulator 2 on

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

q(tot)

total quiescent supply current

standby mode

110

150

junction temperature

150

Voltage regulators

o(REG1)

output voltage of regulator 1

1 mA

REG1

600 mA; V

= 14.4 V

8.0

8.5

9.0

o(REG2)

output voltage of regulator 2

1 mA

REG2

300 mA; V

= 14.4 V

4.75

5.0

5.25

o(REG3)

output voltage of regulator 3

1 mA

REG3

1400 mA; V

= 14.4 V

4.75

5.0

5.25

o(REG4)

output voltage of regulator 4

1 mA

REG4

1 A; V

= 14.4 V

3.14

3.3

3.46

Power switch

drop(SW)

drop-out voltage

= 1 A; V

= 13.5 V

0.45

0.65

= 1.8 A; V

= 13.5 V

1.0

1.8

M(SW)

peak current

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

PINNING

Note

1. The pin is used for final test purposes. In the

application it should be connected directly to ground.

SYMBOL

PIN

DESCRIPTION

REG4

regulator 4 output

IGN

ignition input

IGN

OUT

ignition output (active HIGH)

RES

reset output (active LOW)

RES

reset delay capacitor

EN4

enable input for regulator 4

EN1/3

enable input for regulators 1 and 3

ENSW

enable input for power switch

HOLD

hold output (active LOW)

GND

ground

HEATTAB 11

heat tab connection; note 1

REG2

regulator 2 output

backup switch output

first supply voltage

n.c.

not connected

power switch output

REG1

regulator 1 output

n.c.

not connected

REG3

regulator 3 output

second supply voltage

handbook, halfpage

TDA3681ATH

MGU563

REG4

IGNIN

IGNOUT

RES

CRES

EN4

EN1/3

ENSW

HOLD

GND

VP2

REG3

n.c.

REG1

n.c.

VP1

REG2

HEATTAB

Fig.2 Pin configuration.

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

FUNCTIONAL DESCRIPTION

The TDA3681A is a multiple output voltage regulator with
a power switch, intended for use in car radios with or
without a microcontroller. Because of the low voltage
operation of the car radio, low voltage drop regulators are
used.

Regulator 2 is in regulation when the backup voltage
exceeds 6.5 V for the first time. When regulator 2 is
switched on and its output voltage is within its voltage
range, the reset output is disabled to release the
microcontroller. The reset delay time before release can
be extended by an external capacitor (C

CRES

). This

start-up feature is included to secure a smooth start-up of
the microcontroller at first connection, without uncontrolled
switching of regulator 2 during the start-up sequence.

The charge on the backup capacitor can be used to supply
regulator 2 for a short period when the external supply
voltage drops to 0 V (the time depends on the value of the
backup capacitor).

The output stages of all switchable regulators have an
extremely low noise behaviour and good stability, even for
small values of the output capacitors.

When both regulator 2 and the supply voltages (V

and

> 4.5 V) are available, regulators 1 and 3 can be

operated by means of one enable input.

Regulator 4 and the power switch have a separate enable
input.

Pin HOLD is normally HIGH but is active LOW. Pin HOLD
is connected to an open-collector NPN transistor and must
have an external pull-up resistor to operate. The hold
output is controlled by a low battery voltage (V

) detection

circuit which, when activated, pulls the hold output LOW
(enabled).

The hold circuit is also controlled by the temperature and
load dump protection. Activating the temperature or load
dump protection causes a hold (LOW) during the time that
the protection is activated.

The hold circuit is enabled at low battery voltages. This
indicates that it is not possible to get regulator 1 into
regulation when switching it on: regulator 1 has the highest
output voltage (8.5 V) of all switchable regulators.
Therefore, regulator 1 is the most critical regulator with
respect to an out of regulation condition caused by a low
battery voltage.

The hold function includes hysteresis to avoid oscillations
when the battery voltage crosses the hold threshold levels
for low V

and load dump. The block diagram of the hold

function is illustrated in Fig.3.

All output pins are fully protected. The regulators are
protected against load dump (regulators 1, 3 and 4 switch
off at supply voltages > 18 V) and short-circuit (foldback
current protection).

The power switch contains a current protection. However,
this protection is delayed at short-circuit by the reset delay
capacitor (it should be noted that this is the second
function of the reset delay capacitor C

CRES

). During this

time, the output current is limited to a peak value of at
least 3 A (after a delay, the power switch can deliver 1.8 A
continuous if V

18 V).

In a normal situation, the voltage on the reset delay
capacitor is approximately 3.5 V (depending on the
temperature). The power switch output is approximately
V

0.4 V. At operating temperature, the power switch

can deliver at least 3 A. At high temperature, the switch
can deliver approximately 2 A.

handbook, full pagewidth

low battery

detector

internal

voltage reference

TDA3681A

TEMPERATURE

PROTECTION

LOAD DUMP

buffer

MGU564

HOLD

VP1

Fig.3 Block diagram of the hold circuit.

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

During an overload condition or a short circuit
(V

< V

3.7 V), the voltage on the reset delay

capacitor rises 0.6 V above the voltage of regulator 2. This
rise time depends on the capacitor connected to
pin C

CRES

. During this time, the power switch can deliver

more than 3 A. When regulator 2 is out of regulation and
generates a reset, the power switch can only deliver 2 A
and will immediately go into foldback protection.

At supply voltages > 17 V, the power switch is clamped at
16 V maximum (to avoid externally connected circuits
being damaged by an overvoltage) and the power switch
will switch off at load dump.

Interfacing with the microcontroller (simple full or semi
on/off logic applications) can be realized with an
independent ignition Schmitt trigger and ignition output
buffer (push-pull output).

The timing diagrams are illustrated in Figs 4 and 5.

The second supply voltage V

is used for the switchable

regulators 3 and 4. This input can be connected to a lower
supply voltage of

6 V to reduce the power dissipation of

the TDA3681A. A DC-to-DC converter could be used for
this purpose.

handbook, full pagewidth

VP1 = VP2

enable

regulator 1/3

regulator 1

enable

regulator 4

regulator 3

enable

power
switch

power
switch
output

18 V

8.9 V
7.0 V
4.0 V

1.8 V

1.3 V

1.8 V

1.3 V

8.5 V

0 V

load dump

regulator 4

3.3 V

0 V

5.0 V

0 V

16.9 V

7.0 V

4.0 V

16 V

0 V

1.3 V

load dump

MGL906

Power switch behaviour

VP and enable Schmitt trigger

Fig.4 Timing diagram of regulators and power switch.

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

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

THERMAL CHARACTERISTICS

QUALITY SPECIFICATION

In accordance with

"General Quality Specification For Integrated Circuits (SNW-FQ-611)".

SYMBOL

PARAMETER

CONDITIONS

MIN.

MAX.

UNIT

supply voltage 1

operating

reverse polarity

non-operating

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

supply voltage 2

operating

reverse polarity

non-operating

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

tot

total power dissipation

stg

storage temperature

non-operating

+150

amb

ambient temperature

operating

+85

junction temperature

operating

+150

SYMBOL

PARAMETER

CONDITIONS

VALUE

UNIT

th(j-c)

thermal resistance from junction to case

K/W

th(j-a)

thermal resistance from junction to ambient

in free air

K/W

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

CHARACTERISTICS
V

= V

= 14.4 V; T

amb

= 25

C; measured in test circuit of Fig.8; unless otherwise specified.

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

Supplies

supply voltage 1

operating

9.5

14.4

reverse polarity

non-operating

regulator 2 on

note 1

14.4

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

supply voltage 2

operating

6.5

14.4

reverse polarity

non-operating

regulator 2 on

jump start

10 minutes

load dump protection

50 ms; t

2.5 ms

bat(loaddump)

battery overvoltage
shutdown

and/or V

q(tot)

total quiescent supply
current

= 12.4 V; note 2

105

145

= 14.4 V; note 2

110

150

Schmitt trigger for power supply (regulators 1, 3 and 4)

th(r)

rising threshold voltage

rising

6.5

7.0

7.5

th(f)

falling threshold voltage

falling

4.0

4.5

5.0

hys

hysteresis voltage

2.5

Schmitt trigger for enable input (regulators 1, 3, 4 and power switch)

th(r)

rising threshold voltage

1.4

1.8

2.4

th(f)

falling threshold voltage

0.9

1.3

1.9

hys

hysteresis voltage

REG

= I

= 1 mA

0.5

input leakage current

= 5 V

Reset trigger level of regulator 2

th(r)

rising threshold voltage

rising; I

REG1

= 50 mA;

note 3

4.43

REG2

0.15

REG2

0.1

th(f)

falling threshold voltage

falling; I

REG1

= 50 mA;

note 3

4.4

REG2

0.25

REG2

0.13

Schmitt triggers for hold circuit output

th(r)(VP)

rising threshold voltage
of supply voltage

9.1

9.7

10.3

th(f)(VP)

falling threshold voltage
of supply voltage

9.0

9.4

9.8

hys(VP)

hysteresis voltage of
supply voltage

0.3

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

Reset and hold buffer

sink(L)

LOW-level sink current

RES

0.8 V; V

HOLD

0.8 V

output leakage current

HOLD

= 5 V

0.1

source(H)

HIGH-level source
current

RES

= 5 V

240

400

900

rise time

note 4

fall time

note 4

Reset delay

reset delay capacitor
charge current

CRES

= 0 V

dch

reset delay capacitor
discharge current

CRES

= 3 V;

= V

= 4.3 V

1.0

1.6

th(r)(RES)

rising voltage threshold
reset signal

2.5

3.0

3.5

th(f)(RES)

falling voltage threshold
reset signal

1.0

1.2

1.4

d(RES)

delay reset signal

CRES

= 47 nF; note 5

d(SW)

delay power switch
foldback protection

CRES

= 47 nF; note 6

17.6

Regulator 1 (I

REG1

= 5 mA; unless otherwise specified)

o(off)

output voltage off

400

o(REG1)

output voltage

1 mA

REG1

600 mA

8.0

8.5

9.0

9.5 V

18 V

8.0

8.5

9.0

line

line regulation

9.5 V

18 V

load

load regulation

1 mA

REG1

600 mA

quiescent current

REG1

= 600 mA

SVRR

supply voltage ripple
rejection

= 3 kHz; V

= 2 V (p-p)

drop(REG1)

drop-out voltage

REG1

= 550 mA;

= 8.55 V; note 7

0.4

0.7

m(REG1)

current limit

REG1

> 7 V; note 8

0.65

1.2

sc(REG1)

short-circuit current

0.5

; note 9

250

800

Regulator 2 (I

REG2

= 5 mA; unless otherwise specified)

o(REG2)

output voltage

0.5 mA

REG2

300 mA

4.75

5.0

5.25

7 V

18 V

4.75

5.0

5.25

18 V

50 V;

REG2

150 mA

4.75

5.0

5.25

line

line regulation

6 V

18 V

6 V

50 V

load

load regulation

1 mA

REG2

150 mA

1 mA

REG2

300 mA

100

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

SVRR

supply voltage ripple
rejection

= 3 kHz; V

= 2 V (p-p)

drop(REG2)

drop-out voltage

REG2

= 100 mA;

= 4.75 V; note 7

0.4

0.6

REG2

= 200 mA;

= 5.75 V; note 7

0.8

1.2

REG2

= 100 mA;

= 4.75 V; note 10

0.2

0.5

REG2

= 200 mA;

= 5.75 V; note 10

0.8

1.0

m(REG2)

current limit

REG2

> 4.5 V; note 8

0.32

0.37

sc(REG2)

short-circuit current

0.5

; note 9

120

Regulator 3 (I

REG3

= 5 mA; unless otherwise specified)

o(off)

output voltage off

400

o(REG3)

output voltage

1 mA

REG3

1400 mA

4.75

5.0

5.25

7 V

and/or V

18 V

4.75

5.0

5.25

line

line regulation

7 V

and/or V

18 V

load

load regulation

1 mA

REG3

1400 mA

150

quiescent current

REG3

= 1400 mA

SVRR

supply voltage ripple
rejection

= 3 kHz; V

= 2 V (p-p)

drop(REG3)

drop-out voltage

REG3

= 1400 mA ; V

= 6 V;

note 7

1.5

m(REG3)

current limit

REG3

> 4.5 V; note 8

1.5

1.7

sc(REG3)

short-circuit current

0.5

; note 9

430

750

Regulator 4 (I

REG4

= 5 mA; unless otherwise specified)

o(off)

output voltage off

400

o(REG4)

output voltage

1 mA

REG4

1 A

3.14

3.3

3.46

6.5 V

and/or V

18 V 3.14

3.3

3.46

line

line regulation

6.5 V

and/or V

18 V

load

load regulation

1 mA

REG4

1 A

quiescent current

REG4

= 1 A

SVRR

supply voltage ripple
rejection

= 3 kHz; V

= 2 V (p-p)

drop(REG4)

drop-out voltage

REG4

= 1 A; V

= 5 V; note 7

1.7

2.4

m(REG4)

current limit

REG4

> 3.0 V; note 8

1.1

1.5

sc(REG4)

short-circuit current

0.5

; note 9

470

750

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

Power switch

drop(SW)

drop-out voltage

= 1 A; V

= 13.5 V;

note 11

0.45

0.65

= 1.8 A; V

= 13.5 V;

note 11

1.0

1.8

DC(SW)

continuous current

= 16 V; V

= 13.5 V

1.8

2.0

clamp(SW)

clamping voltage

17 V;

1 mA < I

< 1.8 A

13.5

15.0

16.0

M(SW)

peak current

< 17 V;

notes 6, 12 and 13

fb(SW)

flyback voltage behaviour I

100 mA

+ 3

sc(SW)

short-circuit current

< 1.2 V; note 13

0.5

1.7

Backup switch

DC(BU)

continuous current

> 5 V

0.3

0.35

clamp(BU)

clamping voltage

16.7 V; I

REG2

= 100 mA

r(BU)

reverse current

= 0 V; V

= 12.4 V

900

Schmitt trigger for enable of ignition input

th(r)(IGNIN)

rising threshold voltage
of ignition input

> 3.5 V

1.9

2.2

2.5

th(f)(IGNIN)

falling threshold voltage
of ignition input

> 3.5 V

1.7

2.0

2.3

hys(IGNIN)

hysteresis voltage

> 3.5 V

0.1

0.2

0.5

input leakage current

IGNIN

= 5 V

1.0

i(clamp)

input clamp current

IGNIN

> 50 V

IH(clamp)

HIGH-level input
clamping voltage

IL(clamp)

LOW-level input clamping
voltage

0.6

Ignition buffer

LOW-level output voltage I

IGNOUT

= 0 mA

0.2

0.8

HIGH-level output
voltage

IGNOUT

= 0 mA

4.5

5.0

5.25

LOW-level output current

IGNOUT

0.8 V

0.45

0.8

HIGH-level output current V

IGNOUT

4.5 V

0.45

2.0

output leakage current
(source)

IGNOUT

= 5 V; V

IGNIN

= 0 V

1.0

PLH

LOW-to-HIGH
propagation time

IGNIN

rising from 1.7 to 2.5 V

500

PHL

HIGH-to-LOW
propagation time

IGNIN

falling from

2.5 to 1.7 V

500

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

Notes

1. Minimum operating voltage, only if V

has exceeded 6.5 V.

2. The total quiescent current is measured in the standby mode. Therefore, the enable inputs of regulators 1, 3, 4 and

the power switch are grounded and R

L(REG2)

(see Fig.8).

3. The voltage of the regulator drops as a result of a V

drop for regulators 1 and 2. Regulators 3 and 4 drop as a result

of V

drop.

4. The rise and fall times are measured with a 10 k

pull-up resistor and a 50 pF load capacitor.

5. The delay time depends on the value of the reset delay capacitor:

6. The delay time depends on the value of the reset delay capacitor:

7. The drop-out voltage of regulators 1 and 2 is measured between pins V

and REGn. The drop-out voltage of

regulators 3 and 4 is measured between pins V

and REGn.

8. At current limit, I

m(REGn)

is held constant (see Fig.6).

9. The foldback current protection limits the dissipated power at short-circuit (see Fig.6).

10. The drop-out voltage is measured between pins BU and REG2.

11. The drop-out voltage of the power switch is measured between pins V

and SW.

12. The maximum output current of the power switch is limited to 1.8 A when the supply voltage exceeds 18 V.

13. At short-circuit, I

sc(SW)

of the power switch is held constant to a lower value than the continuous current after a delay

of at least 10 ms (see Fig.7).

Temperature protection

j(sd)

junction temperature for
shutdown

150

160

170

j(hold)

junction temperature for
hold trigger

150

160

170

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

d(RES)

------

C(th)

750

(

)

[ ]

d(SW)

------

C(th)

375

(

)

[ ]

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

TEST AND APPLICATION INFORMATION

Test information

handbook, full pagewidth

MGU568

enable input regulator 4

supply voltage 2

regulator 4
output

C3
10

C2
10

220 nF

C4
10

hold output

ignition output

RL(REG2)
5 k

RL(SW)
12 k

5 V

8.5 V

regulator 3
output

regulator 1
output

regulator 2
output

C5
10

C9
50 pF

C12
50 pF

RL(REG1)
10 k

RL(REG3)
5 k

3.3 V

C6
10

RL(REG4)
5 k

power switch output

reset
output

(1)

(2)

(3)

TDA3681A

ground

heat tab

VP1

supply voltage 1

VENSW

VEN4

enable input regulator 1/3

enable input power switch

VEN1/3

reset delay

capacitor

ignition input

10 k

C11
1 nF

backup switch

output

VIGNIN

C10
100

VBU

VP2

C8
47 nF

R3
10 k

Fig.8 Test circuit.

(1) A minimum capacitor of 220 nF on the supply lines V

and V

is required for stability.

(2) A minimum capacitor of 1

F for backup supply is required for stability.

(3) These capacitors represent the typical input capacitance of CMOS logic connected to the reset and hold outputs.

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

Application information

OISE

Table 1

Noise figures

Note

1. Measured at a bandwidth of 30 kHz.

The noise on the supply line depends on the value of the
supply capacitor and is caused by a current noise (the
output noise of the regulators is translated to a current
noise by the output capacitors). The noise is minimal when
a high frequency capacitor of 220 nF in parallel with an
electrolytic capacitor of 100

F is connected directly to the

supply pins V

, V

and GND.

TABILITY

The regulators are stabilized by the externally connected
output capacitors.

The output capacitors can be selected by using the graphs
given in Figs 9 and 10. When an electrolytic capacitor is
used, its temperature behaviour can cause oscillations at
a low temperature. The two examples below show how an
output capacitor value is selected.

Example 1

Regulators 1, 3 and 4 are stabilized with an electrolytic
output capacitor of 220

F (ESR = 0.15

At T

amb

C, the capacitor value is decreased to

F and the ESR is increased to 1.1

. The regulator

remains stable at T

amb

C (see Fig.9).

Example 2

Regulator 2 is stabilized with a 10

F electrolytic capacitor

(ESR = 3

). At T

amb

C, the capacitor value is

decreased to 3

F and the ESR is increased to 23.1

As can be seen from Fig.10, the regulator will be unstable
at T

amb

Solution

To avoid problems with stability at low temperatures, the
use of tantalum capacitors is recommended. Use a
tantalum capacitor of 10

F or a larger electrolytic

capacitor.

REGULATOR

NOISE FIGURE (

(1)

= 10

= 47

F C

= 100

170

110

440

240

190

120

100

handbook, halfpage

0.1

C (

MGL912

stable region

maximum ESR

100

ESR

(

)

Fig.9

Curve for selecting the value of the output
capacitor for regulators 1, 3 and 4.

handbook, halfpage

0.22

C (

MGL913

stable region

maximum ESR

minimum ESR

100

ESR

(

)

Fig.10 Curve for selecting the value of the output

capacitor for regulator 2.

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

PACKAGE OUTLINE

UNIT

(1)

REFERENCES

OUTLINE

VERSION

EUROPEAN

PROJECTION

ISSUE DATE

IEC

JEDEC

JEITA

0.08

0.04

3.5

0.35

DIMENSIONS (mm are the original dimensions)

Notes

1. Limits per individual lead.

2. Plastic or metal protrusions of 0.25 mm maximum per side are not included.

SOT418-3

10 mm

scale

HSOP20: plastic, heatsink small outline package; 20 leads; low stand-off height

SOT418-3

max.

detail X

3.5
3.2

1.1
0.9

14.5
13.9

1.1
0.8

1.7
1.5

2.5
2.0

0.25

0.07

0.03

13.0
12.6

6.2
5.8

2.9
2.5

0.32
0.23

1.27

(2)

16.0
15.8

(2)

11.1
10.9

0.53
0.40

(A3)

pin 1 index

02-02-12
03-07-23

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

SOLDERING

Introduction to soldering surface mount packages

This text gives a very brief insight to a complex technology.
A more in-depth account of soldering ICs can be found in
our

"Data Handbook IC26; Integrated Circuit Packages"

(document order number 9398 652 90011).

There is no soldering method that is ideal for all surface
mount IC packages. Wave soldering can still be used for
certain surface mount ICs, but it is not suitable for fine pitch
SMDs. In these situations reflow soldering is
recommended.

Reflow soldering

Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.
Driven by legislation and environmental forces the
worldwide use of lead-free solder pastes is increasing.

Several methods exist for reflowing; for example,
convection or convection/infrared heating in a conveyor
type oven. Throughput times (preheating, soldering and
cooling) vary between 100 and 200 seconds depending
on heating method.

Typical reflow peak temperatures range from
215 to 270

C depending on solder paste material. The

top-surface temperature of the packages should
preferably be kept:

below 220

C (SnPb process) or below 245

C (Pb-free

process)

for all BGA and SSOP-T packages

for packages with a thickness

2.5 mm

for packages with a thickness < 2.5 mm and a

volume

350 mm

so called thick/large packages.

below 235

C (SnPb process) or below 260

C (Pb-free

process) for packages with a thickness < 2.5 mm and a
volume < 350 mm

so called small/thin packages.

Moisture sensitivity precautions, as indicated on packing,
must be respected at all times.

Wave soldering

Conventional single wave soldering is not recommended
for surface mount devices (SMDs) or printed-circuit boards
with a high component density, as solder bridging and
non-wetting can present major problems.

To overcome these problems the double-wave soldering
method was specifically developed.

If wave soldering is used the following conditions must be
observed for optimal results:

Use a double-wave soldering method comprising a
turbulent wave with high upward pressure followed by a
smooth laminar wave.

For packages with leads on two sides and a pitch (e):

larger than or equal to 1.27 mm, the footprint

longitudinal axis is preferred to be parallel to the
transport direction of the printed-circuit board;

smaller than 1.27 mm, the footprint longitudinal axis

must be parallel to the transport direction of the
printed-circuit board.

The footprint must incorporate solder thieves at the
downstream end.

For packages with leads on four sides, the footprint must
be placed at a 45

angle to the transport direction of the

printed-circuit board. The footprint must incorporate
solder thieves downstream and at the side corners.

During placement and before soldering, the package must
be fixed with a droplet of adhesive. The adhesive can be
applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the
adhesive is cured.

Typical dwell time of the leads in the wave ranges from
3 to 4 seconds at 250

C or 265

C, depending on solder

material applied, SnPb or Pb-free respectively.

A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.

Manual soldering

Fix the component by first soldering two
diagonally-opposite end leads. Use a low voltage (24 V or
less) soldering iron applied to the flat part of the lead.
Contact time must be limited to 10 seconds at up to
300

When using a dedicated tool, all other leads can be
soldered in one operation within 2 to 5 seconds between
270 and 320

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

Suitability of surface mount IC packages for wave and reflow soldering methods

Notes

1. For more detailed information on the BGA packages refer to the

"(LF)BGA Application Note" (AN01026); order a copy

from your Philips Semiconductors sales office.

2. All surface mount (SMD) packages are moisture sensitive. Depending upon the moisture content, the maximum

temperature (with respect to time) and body size of the package, there is a risk that internal or external package
cracks may occur due to vaporization of the moisture in them (the so called popcorn effect). For details, refer to the
Drypack information in the

"Data Handbook IC26; Integrated Circuit Packages; Section: Packing Methods".

3. These transparent plastic packages are extremely sensitive to reflow soldering conditions and must on no account

be processed through more than one soldering cycle or subjected to infrared reflow soldering with peak temperature
exceeding 217

C measured in the atmosphere of the reflow oven. The package body peak temperature

must be kept as low as possible.

4. These packages are not suitable for wave soldering. On versions with the heatsink on the bottom side, the solder

cannot penetrate between the printed-circuit board and the heatsink. On versions with the heatsink on the top side,
the solder might be deposited on the heatsink surface.

5. If wave soldering is considered, then the package must be placed at a 45

angle to the solder wave direction.

The package footprint must incorporate solder thieves downstream and at the side corners.

6. Wave soldering is suitable for LQFP, TQFP and QFP packages with a pitch (e) larger than 0.8 mm; it is definitely not

suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.

7. Wave soldering is suitable for SSOP, TSSOP, VSO and VSSOP packages with a pitch (e) equal to or larger than

0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.

8. Hot bar or manual soldering is suitable for PMFP packages.

PACKAGE

(1)

SOLDERING METHOD

WAVE

REFLOW

(2)

BGA, LBGA, LFBGA, SQFP, SSOP-T

(3)

, TFBGA, VFBGA

not suitable

suitable

DHVQFN, HBCC, HBGA, HLQFP, HSQFP, HSOP, HTQFP,
HTSSOP, HVQFN, HVSON, SMS

not suitable

(4)

suitable

PLCC

(5)

, SO, SOJ

suitable

LQFP, QFP, TQFP

not recommended

(5)(6)

suitable

SSOP, TSSOP, VSO, VSSOP

not recommended

(7)

suitable

PMFP

(8)

not suitable

2003 Aug 29

Philips Semiconductors

Product specification

Multiple voltage regulator with
switch and ignition buffer

TDA3681A

DATA SHEET STATUS

Notes

1. Please consult the most recently issued data sheet before initiating or completing a design.

2. The product status of the device(s) described in this data sheet may have changed since this data sheet was

published. The latest information is available on the Internet at URL http://www.semiconductors.philips.com.

3. For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.

LEVEL

DATA SHEET

STATUS

(1)

PRODUCT

STATUS

(2)(3)

DEFINITION

Objective data

Development

This data sheet contains data from the objective specification for product
development. Philips Semiconductors reserves the right to change the
specification in any manner without notice.

Preliminary data Qualification

This data sheet contains data from the preliminary specification.
Supplementary data will be published at a later date. Philips
Semiconductors reserves the right to change the specification without
notice, in order to improve the design and supply the best possible
product.

III

Product data

Production

This data sheet contains data from the product specification. Philips
Semiconductors reserves the right to make changes at any time in order
to improve the design, manufacturing and supply. Relevant changes will
be communicated via a Customer Product/Process Change Notification
(CPCN).

DEFINITIONS

Short-form specification

The data in a short-form

specification is extracted from a full data sheet with the
same type number and title. For detailed information see
the relevant data sheet or data handbook.

Limiting values definition

Limiting values given are in

accordance with the Absolute Maximum Rating System
(IEC 60134). Stress above one or more of the limiting
values may cause permanent damage to the device.
These are stress ratings only and operation of the device
at these or at any other conditions above those given in the
Characteristics sections of the specification is not implied.
Exposure to limiting values for extended periods may
affect device reliability.

Application information

Applications that are

described herein for any of these products are for
illustrative purposes only. Philips Semiconductors make
no representation or warranty that such applications will be
suitable for the specified use without further testing or
modification.

DISCLAIMERS

Life support applications

These products are not

designed for use in life support appliances, devices, or
systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips
Semiconductors customers using or selling these products
for use in such applications do so at their own risk and
agree to fully indemnify Philips Semiconductors for any
damages resulting from such application.

Right to make changes

Philips Semiconductors

reserves the right to make changes in the products -
including circuits, standard cells, and/or software -
described or contained herein in order to improve design
and/or performance. When the product is in full production
(status `Production'), relevant changes will be
communicated via a Customer Product/Process Change
Notification (CPCN). Philips Semiconductors assumes no
responsibility or liability for the use of any of these
products, conveys no licence or title under any patent,
copyright, or mask work right to these products, and
makes no representations or warranties that these
products are free from patent, copyright, or mask work
right infringement, unless otherwise specified.

SCA75

All rights are reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner.

The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed
without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license
under patent- or other industrial or intellectual property rights.

Philips Semiconductors a worldwide company

Contact information

For additional information please visit http://www.semiconductors.philips.com.

Fax: +31 40 27 24825

For sales offices addresses send e-mail to: sales.addresses@www.semiconductors.philips.com.

Printed in The Netherlands

R32/02/pp

Date of release:

2003 Aug 29

Document order number:

9397 750 11719

Document Outline

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: TDA3681A

Document Outline

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: TDA3681A