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TK11227B中文资料

October 1999 TOKO, Inc.Page 1

Supply Voltage.........................................................16 V Power Dissipation SOT-23L (Note1)..................600 mW Power Dissipation SOT-89 (Note1)....................900 mW Reverse Bias............................................................10 V Storage Temperature Range...................-55 to +150 °C Operating Temperature Range...................-30 to +80 °C Operating Voltage Range............................1.8 to 14.5 V Junction Temperature...........................................150 °C

ABSOLUTE MAXIMUM RATINGS TK112xxBC (V

OUT

≥ 2.0 V)

TK112xxBC ELECTRICAL CHARACTERISTICS (V

OUT ≥ 2.0 V)

Test conditions: T A= 25 °C, unless otherwise specified.

Note 1: When mounted as recommended. Derate at 4.8 mW/°C for SOT-23L and 6.4 mW/°C for SOT-89 packages for operation above 25°C. Note 2: Refer to “Definition of Terms.”

Note 3: Ripple rejection and noise voltage are affected by the value and characteristics of the capacitor used.

Note 4: Output noise voltage can be reduced by connecting a capacitor to a noise pass terminal.

Gen. Note: Parameters with min. or max. values are 100% tested at T

A = 25 °C.

L

O

B

M

Y

S R

E

T

E

M

A

R

A

P S

N

O I T I D

N

O

C

T

S

E

T N I

M P

Y

T X

A

M S

T I N

U

I Q

t n

e r r u

C

t n

e c s e i u

Q I

T

U

O

I

g

n i d

u l c x

E

,A

m

=

T

N

O

C

7

10

5

2A

μ

I

Y

B

T

S

t n

e r r u

C

y b

d

n

a t S V

N I

F

F

O

t u

p t u

O

,V

8

=1.0A

μ

V

T

U

O

e

g

a t l o

V

t u

p t u

O I

T

U

O

A

m

3

=1

e l b

a

T

e

e

S V g

e

R

e

n i L n

o i t a l u

g

e

R

e

n i L V

T

U

O

≤)2

e t o

N(,V

5.50.302V

m

V

T

U

O

≥)2

e t o

N(,V

6.55104V

m

g

e

R

d

a

o

L n

o i t a l u

g

e

R

d

a

o

L I

T

U

O

)2

e t o

N(,A

m

6

o t

1

=60

3V

m

I

T

U

O

)2

e t o

N(,A

m

1

o t

1

=8

10

6V

m

I

T

U

O

)2

e t o

N(,A

m

5

1

o t

1

=3

20

9V

m

V

P

O

R

D

e

g

a t l o

V

t u

o

p

o r D

I

T

U

O

)2

e t o

N(,A

m

6

=2

1.00

2.0V

I

T

U

O

)2

e t o

N(,A

m

5

1

=6

2.09

3.0V

I

T

U O

t n

e r r u

C

t u

p t u

O

s u

o

u

n i t n

o

C)2

e t o

N(0

5

1A

m

I

)E

S

L

U

P(T

U

O

t n

e r r u

C

t u

p t u

O

e s l u

P e l c y c

y t u

d

%

5.2

1

,e s l u

p

s

m

50

8

1A

m

R

R n

o i t c e j e

R

e l p

p i R

C

,z

H

4

=

f

L

C

,F

μ

1

=

N

,F

μ

1.0

=

V

N I

V

=

T

U

O

I

,V

5.1

+

T

U

O

,A

m

3

=

V

E

L

P

P I R

)3

e t o

N(,s

m

r V

m

1

=

6B

d

V

O

N

e

g

a t l o

V

e s i o

N

t u

p t u

O

z

H

1≤f≤C

,z

H

k

8

L

,F

μ

1

=

C

N

V

,F

μ

1.0

=

N

C

V

=

T

U

O

,V

5.1

+

I

T

U

O

)4,3

s e t o

N(,A

m

6

=

3s

m

r V

μ

V

f e r

l a

n i m

r e

T

s s a

p y

B

e s i o

N

e

g

a t l o

V

5

2.1V

?V

T

U

O /?T t n

e i c i

f f e

o

C

e r u t a r e

p

m

e

T I

T

U

O

A

m

1

=0

4C

°/

m

p

p

S

N

O I T

A

C I F I C

E

P

S

L

A

N I

M

R

E

T

L

O

R

T

N O

C

I

T

N

O

C

t n

e r r u

C

l o r t n

o

C V

T

N

O

C

N

O

t u

p t u

O

,V

8.1

=2

15

3A

μ

V

)N

O

(T

N

O

C

N

O

e

g

a t l o

V

l o r t n

o

C N

O

t u

p t u

O8.1V

V

)F

F

O

(T

N

O

C

F

F

O

e

g

a t l o

V

l o r t n

o

C F

F

O

t u

p t u

O6.0V

Page 2October 1999 TOKO, Inc.

October 1999 TOKO, Inc.Page 3

Supply Voltage.........................................................16 V Power Dissipation SOT-23L (Note1)..................600 mW Power Dissipation SOT-89 (Note1)....................900 mW Reverse Bias..............................................................7 V

Storage Temperature Range ...................-55 to +150 °C Operating Temperature Range ...................-30 to +80 °C Operating Voltage Range............................1.8 to 14.5 V Junction Temperature ...........................................150 °C

ABSOLUTE MAXIMUM RATINGS TK1121xBC (V OUT ≤ 1.9 V)

TK1121xBC ELECTRICAL CHARACTERISTICS (V OUT ≤ 1.9 V)

Test conditions: T A = 25 °C, unless otherwise specified.

Note 1: When mounted as recommended. Derate at 4.8 mw/°C for SOT-23L and 6.4 mw/°C for SOT-89 packages for operation above 25 °C.Note 2: Refer to “Definition of Terms.”

Note 3: Ripple rejection and noise voltage are affected by the value and characteristics of the capacitor used.Note 4: Output noise voltage can be reduced by connecting a capacitor to a noise pass terminal.Gen Note: Parameters with min. or max. values are 100% tested at T A = 25 °C.

L O B M Y S R

E T E M A R A P S

N O I T I D N O C T S E T N

I M P Y T X A M S T I N U I Q t n e r r u C t n e c s e i u Q I T U O I g n i d u l c x E ,A m 0=T N O C 0

71052A μI Y B T S t n e r r u C y b d n a t S V N I F F O t u p t u O ,V 8=1

.0A μV T U O e g a t l o V t u p t u O I T U O A m 03=2

e l b a T e e S V g

e R e n i L n

o i t a l u g e R e n i L )

2e t o N (0.302V m g e R d a o L n

o i t a l u g e R d a o L I T U O )2e t o N (,A m 06o t 1=603V m I T U O )2e t o N (,A m 001o t 1=8

106V m I T U O t n e r r u C t u p t u O s u o u n i t n o C V 4.2≤V N I ≤)2e t o N (,V 6.2031A m V N I ≥)2e t o N (,V 6.2051A m I )E S L U P (T U O t

n e r r u C t u p t u O e s l u P V ,e s l u p s m 5N I ≥,V 6.2e

l c y c y t u d %5.210

81A

m R

R n o i t c e j e R e l p p i R C ,z H 004=f L C ,F μ01=N ,F μ1.0=V N I V =T U O I ,V 5.1+T U O ,A m 03=V E L P P I R )3e t o N (,s m r V m 001=55B

d V O N

e g a t l o V e s i o N t u p t u O z H 01≤

f ≤C ,z H k 08L ,F μ01=C N V ,F μ1.0=N C V =T U O ,V 5.1+I T U O )

4,3s e t o N (,A m 06=03s

m r V μV f

e r l a n i m r e T s s a p y B e s i o N e

g a t l o V 5

2.1V ?V T U O /?T

t

n e i c i f f e o C e r u t a r e p m e T I T U O A

m 01=0

4C

°/m p p S N O I T A C I F I C E P S L A N I M R E T L O R T N O C I T N O C t n e r r u C l o r t n o C V T N O C N O t u p t u O ,V 8.1=2

15

3A μV )N O (T N O C N O e g a t l o V l o r t n o C N O t u p t u O 8

.1V V )

F F O (T N O C F

F O e g a t l o V l o r t n o C F

F O t u p t u O 6

.0V

Page 4October 1999 TOKO, Inc.

TK112xxBI ELECTRICAL CHARACTERISTICS (V OUT ≥ 2.5 V)

Test conditions: T A = -40 to 85 °C, unless otherwise specified.Supply Voltage.........................................................16 V Power Dissipation SOT-23L (Note1)..................600 mW Power Dissipation SOT-89 (Note1)....................900 mW Reverse Bias............................................................10 V

Storage Temperature Range ...................-55 to +150 °C Operating Temperature Range ...................-40 to +85 °C Operating Voltage Range............................1.8 to 14.5 V Junction Temperature ...........................................150 °C

ABSOLUTE MAXIMUM RATINGS TK112xxBI (V OUT ≥ 2.5 V)

L O B M Y S R

E T E M A R A P S

N O I T I D N O C T S E T N

I M P Y T X A M S T I N U I Q t n e r r u C t n e c s e i u Q I T U O I g n i d u l c x E ,A m 0=T N O C 0

71003A μI Y B T S t n e r r u C y b d n a t S V N I F F O t u p t u O ,V 8=2

.0A μV T U O e g a t l o V t u p t u O I T U O A m 03=3

e l b a T e e S V g

e R e n i L n

o i t a l u g e R e n i L V T U O ≤)2e t o N (,V 5.50.352V m V T

U O )

2e t o N (,V 6.55104V m g e R d a o L n

o i t a l u g e R d a o L I T U O )

2e t o N (,A m 06o t 1=604V m I T U O )2e t o N (,A m 001o t 1=8108V m I T U O )

2e t o N (,A m 051o t 1=32011V m V P O R D e

g a t l o V t u o p o r D I T U O )2e t o N (,A m 06=21.032.0V I T U O )2e t o N (,A m 051=6

2.004.0V I T U O t n e r r u C t u p t u O s u o u n i t n o C )

2e t o N (051A m I )E S L U P (T U O t n e r r u C t u p t u O e s l u P e l c y c y t u d %5.21,e s l u p s m 50

81A m R

R n

o i t c e j e R e l p p i R C ,z H 004=f L C ,F μ01=N ,F μ1.0=V N I V =T U O I ,V 5.1+T U O ,A m 03=V E L P P I R )3e t o N (,s m r V m 001=0

6B

d V O N

e g a t l o V e s i o N t u p t u O z H 01≤

f ≤C ,z H k 08L ,F μ01=C N V ,F μ1.0=N C V =T U O ,V 5.1+I T U O )

4,3s e t o N (,A m 06=03s

m r V μV f

e r l a n i m r e T s s a p y B e s i o N e

g a t l o V 5

2.1V ?V T U O /?T

t

n e i c i f f e o C e r u t a r e p m e T I T U O A

m 01=0

4C

°/m p p S N O I T A C I F I C E P S L A N I M R E T L O R T N O C I T N O C t n e r r u C l o r t n o C V T N O C N O t u p t u O ,V 8.1=2

10

4A μV )N O (T N O C N O e g a t l o V l o r t n o C N O t u p t u O 0

.2V V )

F F O (T N O C F

F O e g a t l o V l o r t n o C F

F O t u p t u O 5

.0V

Note 1: When mounted as recommended. Derate at 4.8 mw/°C for SOT-23L and 6.4 mw/°C for SOT-89 packages for operation above 25 °C.Note 2: Refer to “Definition of Terms.”

Note 3: Ripple rejection and noise voltage are affected by the value and characteristics of the capacitor used.Note 4: Output noise voltage can be reduced by connecting a capacitor to a noise pass terminal.Gen Note: Parameters with min. or max. values are 100% tested at T A = 25 °C.Gen Note: For Line Regulation, typ. and max. is changed to V OUT > 5.6 V.

Output Voltage V

OUT(MIN)V

OUT(MAX)

Test

Voltage Code Voltage 1.3 V13 1.240 V 1.36 V 2.4 V 1.4 V14 1.340 V 1.46 V 2.4 V 1.5 V15 1.440 V 1.560 V 2.4 V 1.6 V16 1.540 V 1.660 V 2.4 V 1.7 V17 1.640 V 1.760 V 2.4 V 1.8 V18 1.740 V 1.860 V 2.4 V 1.9 V19 1.804 V 1.960 V 2.4 V

Output Voltage V

OUT(MIN)V

OUT(MAX)

Test

Voltage Code Voltage 2.0 V20 1.940 V 2.060 V 3.0 V 2.1 V21 2.040 V 2.160 V 3.1 V 2.2 V22 2.140 V 2.260 V 3.2 V 2.3 V23 2.240 V 2.360 V 3.3 V 2.4 V24 2.340 V 2.460 V 3.4 V 2.5 V25 2.440 V 2.560 V 3.5 V 2.6 V26 2.540 V 2.660 V 3.6 V 2.7 V27 2.640 V 2.760 V 3.7 V 2.8 V28 2.740 V 2.860 V 3.8 V

2.9 V29 2.840 V 2.960 V

3.9 V

3.0 V30 2.940 V 3.060 V

4.0 V 3.1 V31 3.040 V 3.160 V 4.1 V 3.2 V32 3.140 V 3.260 V 4.2 V 3.3 V33 3.240 V 3.360 V 4.3 V 3.4 V34 3.335 V 3.465 V 4.4 V 3.5 V35 3.435 V 3.565 V 4.5 V 3.6 V36 3.535 V 3.665 V 4.6 V Output Voltage V

OUT(MIN)

V

OUT(MAX)

Test Voltage Code Voltage 3.7 V37 3.630 V 3.770 V 4.7 V 3.8 V38 3.725 V 3.875 V 4.8 V

3.9 V39 3.825 V 3.975 V

4.9 V

4.0 V40 3.920 V 4.080 V

5.0 V 4.1 V41 4.020 V 4.180 V 5.1 V 4.2 V42 4.120 V 4.280 V 5.2 V 4.3 V43 4.215 V 4.385 V 5.3 V 4.4 V44 4.315 V 4.485 V 5.4 V 4.5 V45 4.410 V 4.590 V 5.5 V 4.6 V46 4.510 V 4.690 V 5.6 V 4.7 V47 4.605 V 4.795 V 5.7 V 4.8 V48 4.705 V 4.895 V 5.8 V

4.9 V49 4.800 V

5.000 V 5.9 V

5.0 V50 4.900 V 5.100 V

6.0 V 5.5 V55 5.390 V 5.610 V 6.5 V 8.0 V80

7.840 V

8.160 V

9.0 V

TK112xxBMC ELECTRICAL CHARACTERISTICS TABLE 1

Test conditions: T A= 25 °C, I OUT = 30 mA, unless otherwise specified.

TK112xxBC ELECTRICAL CHARACTERISTICS TABLE 2

Test conditions: T A= 25 °C, I OUT = 30 mA, unless otherwise specified.

October 1999 TOKO, Inc.Page 5

TK112xxBI ELECTRICAL CHARACTERISTICS TABLE 3

Test Conditions: V

IN = V

OUT(TYP)

+ 1 V, I

OUT

= 30 mA, unless otherwise specified.

Room Temp. Range (T

A

= 25 °C) Full Temp. Range (T

A

= -40 to +85 °C)

Output Voltage V

OUT(MIN)V

OUT(MAX)

V

OUT(MIN)

V

OUT(MAX)

Voltage Code

2.5 V25 2.440 V 2.560 V 2.400 V 2.600 V 2.6 V26 2.540 V 2.660 V 2.500 V 2.700 V 2.7 V27 2.640 V 2.760 V 2.600 V 2.800 V 2.8 V28 2.750 V 2.860 V 2.700 V 2.900 V

2.9 V29 2.840 V 2.960 V 2.800 V

3.000 V

3.0 V30 2.940 V 3.060 V 2.900 V 3.100 V 3.1 V31 3.040 V 3.160 V 3.000 V 3.200 V 3.2 V32 3.140 V 3.260 V 3.095 V 3.305 V 3.3 V33 3.240 V 3.360 V 3.190 V 3.410 V 3.4 V34 3.335 V 3.465 V 3.290 V 3.510 V 3.5 V35 3.435 V 3.565 V 3.385 V 3.615 V 3.6 V36 3.535 V 3.665 V 3.485 V 3.720 V 3.7 V37 3.630 V 3.770 V 3.580 V 3.820 V 3.8 V38 3.725 V 3.875 V 3.675 V 3.925 V

3.9 V39 3.825 V 3.975 V 3.770 V

4.030 V

4.0 V40 3.920 V 4.080 V 3.870 V 4.130 V 4.1 V41 4.020 V 4.180 V 3.965 V 4.235 V 4.2 V42 4.120 V 4.280 V 4.060 V 4.335 V 4.3 V43 4.215 V 4.385 V 4.160 V 4.440 V 4.4 V44 4.315 V 4.485 V 4.255 V 4.545 V 4.5 V45 4.410 V 4.590 V 4.350 V 4.645 V 4.6 V46 4.510 V 4.690 V 4.450 V 4.750 V 4.7 V47 4.605 V 4.795 V 4.545 V 4.850 V 4.8 V48 4.705 V 4.895 V 4.640 V 4.955 V

4.9 V49 4.800 V

5.000 V 4.740 V 5.060 V

5.0 V50 4.900 V 5.100 V 4.835 V 5.165 V 5.5 V55 5.390 V 5.610 V 5.320 V 5.680 V 8.0 V807.840 V8.160 V7.745 V8.265 V

Page 6October 1999 TOKO, Inc.

October 1999 TOKO, Inc.Page 7

Page 8October 1999 TOKO, Inc.

GROUND CURRENT VS. OUTPUT

CURRENT

I OUT (mA)

I G N D (m A )

1086420

REVERSE BIAS CURRENT

(V IN = 0 V)

020

V REV (V)

I R E V (μA )

100200300400

50010

QUIESCENT CURRENT (OFF MODE) VS. INPUT VOLTAGE

020

V IN (V)

I Q (p A )

50

100

10QUIESCENT CURRENT (ON MODE) vs. INPUT VOLTAGE

5

I Q (m A )

0.5

1.0

2.5V IN (V)

GROUND CURRENT

-50

100

0I G N D (m A )

2

1

50

T A (°C)

DROPOUT VOLTAGE

-50

100

V D R O P (m V )

50

T A (°C)

CONTROL CURRENT

-50100

I C O N T (μA )

10

50

3040

50T A (°C)

20

V (V , ON POINT)

-50

100

0V C O N T (V )

501.0

2.0

T A (°C)

0QUIESCENT CURRENT (ON MODE) VS . INPUT VOLTAGE

10

0I Q (m A )

1

2

5V IN (V)

TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)

T A = 25 °C, unless otherwise specified.

October 1999 TOKO, Inc.Page 9

Page 10October 1999 TOKO, Inc.

OUTPUT VOLTAGE vs. OUTPUT

CURRENT

V O U T (V )

1.2

1.3

I OUT (mA)

OUTPUT VOLTAGE vs. INPUT

VOLTAGE

V O U T (V )

1.3

1.2

V IN (V)

OUTPUT VOLTAGE vs. OUTPUT

CURRENT

V O U T (V )

1.2

1.3

1.4

I OUT (mA)

OUTPUT VOLTAGE vs. INPUT

VOLTAGE

V O U T (V )

1.21.41.3

V IN

(V)

OUTPUT VOLTAGE vs. OUTPUT

CURRENT

V O U T (V )

1.3

1.4

1.5

I OUT (mA)

OUTPUT VOLTAGE vs. INPUT

VOLTAGE

V O U T (V )

V IN (V)TK11213B

TK11214B

TK11215B

TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)

T A = 25 °C, unless otherwise specified.

October 1999 TOKO, Inc.Page 11

Page 12October 1999 TOKO, Inc.

OUTPUT VOLTAGE VS. INPUT

VOLTAGE

V O U T (V )

1.71.9

1.8

V IN (V)TK11219B

OUTPUT VOLTAGE vs. OUTPUT

CURRENT

V O U T (V )

1.7

1.8

1.9I OUT (mA)

TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)

T A = 25 °C, unless otherwise specified.

October 1999 TOKO, Inc.Page 13

DEFINITION AND EXPLANATION OF TECHNICAL TERMS

OUTPUT VOLTAGE (V OUT )

The output voltage is specified with V IN = (V OUT(TYP) + 1 V)and I OUT = 30 mA.

DROPOUT VOLTAGE (V DROP )

The dropout voltage is the difference between the input voltage and the output voltage at which point the regulator starts to fall out of regulation. Below this value, the output voltage will fall as the input voltage is reduced. It is dependent upon the load current and the junction temperature.

OUTPUT CURRENT (I OUT(MAX))

This is the maximum continuous output current specified under the condition where the output voltage drops 0.3 V below the value specified with I OUT = 30 mA. The input voltage is set to V OUT +1 V, and the current is pulsed to minimize temperature effect.

CONTINUOUS OUTPUT CURRENT (I OUT )

Normal operating output current. This is limited by package power dissipation.

PULSE OUTPUT CURRENT (I OUT(PULSE))

Maximum pulse width 5 ms at V OUT upper 2.0 V; 7 ms. at V OUT under 1.9 V; duty cycle 12.5%: pulse load only.LINE REGULATION (Line Reg)

Line regulation is the ability of the regulator to maintain a constant output voltage as the input voltage changes. The line regulation is specified as the input voltage is changed from V IN = V OUT(TYP) + 1 V to V IN = V OUT(TYP) + 6 V.LOAD REGULATION (Load Reg)

Load regulation is the ability of the regulator to maintain a constant output voltage as the load current changes. It is a pulsed measurement to minimize temperature effects with the input voltage set to V IN = V OUT +1 V. The load regulation is specified under two output current step conditions of 1 mA to 60 mA and 1 mA to 100 mA.

QUIESCENT CURRENT (I Q )

The quiescent current is the current which flows through the ground terminal under no load conditions (I OUT = 0 mA).GROUND CURREN T (I GND )

Ground current is the current which flows through the ground pin(s). It is defined as I IN - I OUT , excluding I CONT .RIPPLE REJECTION RATIO (RR)

Ripple rejection is the ability of the regulator to attenuate the ripple content of the input voltage at the output. It is specified with 100 mVrms, 400 Hz superimposed on the input voltage, where V IN = V OUT + 1.5 V. The output decoupling capacitor is set to 10 μF, the noise bypass capacitor is set to 0.1 μF, and the load current is set to 30mA. Ripple rejection is the ratio of the ripple content of the output vs. the input and is expressed in dB.STANDBY CURRENT (I STBY )

Standby current is the current which flows into the regulator when the output is turned off by the control function (V CONT = 0 V). It is measured with V IN = 8 V (9 V for the 8V output device).SENSOR CIRCUITS Overcurrent Sensor

The overcurrent sensor protects the device in the event that the output is shorted to ground.Thermal Sensor

The thermal sensor protects the device in the event that the junction temperature exceeds the safe value (T J = 150°C). This temperature rise can be caused by external heat,excessive power dissipation caused by large input to output voltage drops, or excessive output current. The regulator will shut off when the temperature exceeds the safe value. As the junction temperatures decrease, the regulator will begin to operate again. Under sustained fault conditions, the regulator output will oscillate as the device turns off then resets. Damage may occur to the device under extreme fault conditions.

Page 14October 1999 TOKO, Inc.

Reverse Voltage Protection

Reverse voltage protection prevents damage due to the output voltage being higher than the input voltage. This fault condition can occur when the output capacitor remains charged and the input is reduced to zero, or when an external voltage higher than the input voltage is applied to the output side.CONTROL FUNCTION

DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)

SOT-23L

SOT-89

CONTROL PIN CURRENT VS.

VOLTAGE

V CONT (V)

I C O N T (μA )

If the control function is not used, connect the control terminal to V IN . When the control function is used, the control current can be reduced by inserting a series resistor (R CONT ) between the control terminal and V IN . The value of this resistor should be determined from the graph below.

October 1999 TOKO, Inc.Page 15

V O U T

V

Page 16October 1999 TOKO, Inc.

the output side is shorted. Input current gradually falls as temperature rises. You should use the value when thermal equilibrium is reached.

The range of usable currents can also be found from the graph below.

Procedure:1)Find P D

2)P D1 is taken to be P D x (~0.8 - 0.9)3)Plot P D1 against 25 °C

4)

Connect P D1 to the point corresponding to the 150 °C with a straight line.

5)In design, take a vertical line from the maximum

operating temperature (e.g., 75 °C) to the derating curve.

6)Read off the value of P D against the point at which the

vertical line intersects the derating curve. This is taken as the maximum power dissipation, D PD .The maximum operating current is:

I OUT = (D PD / (V IN(MAX) - V OUT )

PACKAGE POWER DISSIPATION (P D )

This is the power dissipation level at which the thermal sensor is activated. The IC contains an internal thermal sensor which monitors the junction temperature. When the junction temperature exceeds the monitor threshold of 150°C, the IC is shut down. The junction temperature rises as the difference between the input power (V IN x I IN )and the output power (V OUT x I OUT ) increases. The rate of temperature rise is greatly affected by the mounting pad configuration on the PCB, the board material, and the ambient temperature. When the IC mounting has good thermal conductivity, the junction temperature will be low even if the power dissipation is great. When mounted on the recommended mounting pad, the power dissipation of the SOT-23L is increased to 600 mW. For operation at ambient temperatures over 25 °C, the power dissipation of the SOT-23L device should be derated at 4.8 mW/°C. The power dissipation of the SOT-89 package is 900 mW when mounted as recommended. Derate the power dissipation at 7.2 mW/°C for operation above 25 °C. To determine the power dissipation for shutdown when mounted, attach the device on the actual PCB and deliberately increase the output current (or raise the input voltage) until the thermal protection circuit is activated. Calculate the power dissipation of the device by subtracting the output power from the input power. These measurements should allow for the ambient temperature of the PCB. The value obtained from P D /(150 °C - T A ) is the derating factor. The PCB mounting pad should provide maximum thermal conductivity in order to maintain low device temperatures.As a general rule, the lower the temperature, the better the reliability of the device. The thermal resistance when mounted is expressed as follows:

T j = 0jA x P D + T A

For Toko ICs, the internal limit for junction temperature is 150 °C. If the ambient temperature (T A ) is 25 °C, then:

150 °C = 0jA x P D + 25 °C 0jA = 125 °C/ P D

P D is the value when the thermal sensor is activated. A simple way to determine P D is to calculate V IN x I IN when

DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)

P D

D PD

(mW)T A (°C)

October 1999 TOKO, Inc.Page 17

Page 18October 1999 TOKO, Inc.

1000

100

10

1

0.1

0.01

1

50

100

150

I OUT

(mA)

E S R (?)

1000

100

10

1

0.1

0 .01

1

50

100

150

I OUT (mA)

E S R (?

)

1000

100

10

1

0.1 0.01

1

50

100

150

I OUT (mA)

E S R (?)

1000

100

10

1

0.1

0.01

1

50

100

150

I OUT (mA)

E S R (?)

APPLICATION INFORMATION

In general, the capacitor should be at least 1 μF (aluminum electrolytic) and be rated for the actual ambient operating temperature range. The table below shows typical characteristics for several types and values of capacitance. Please note that the ESR varies widely depending upon manufacturer, type, size, and material.

C L = 1 μF

C L = 2.2 μF

C L = 3.3 μF

C L = 10 μF

Note: ESR is measured at 10 kHz.

INPUT-OUTPUT CAPACITORS

Linear regulators require an output capacitor in order to maintain regulator loop stability. This capacitor should be selected to ensure stable operation over the desired temperature and load range. The graphs below show the effects of

capacitance value and ESR on the stable operation area.

V =

ESR

Capacitance

Aluminum Capacitor Tantalum Capacitor Ceramic Capacitor 1.0 μF 2.4? 2.3?0.140?2.2 μF 2.0? 1.9?0.059?3.3 μF 4.6? 1.0?0.049?10 μF

1.4?

0.5?

0.025?

October 1999 TOKO, Inc.Page 19

Page 20October 1999 TOKO, Inc.

COMPARISON BETWEEN TK112xx and TK112xxB

TK112xx

TK112xxB

QUIESCENT CURRENT vs.

OUTPUT CURRENT

I OUT (mA)

I Q (m A )

QUIESCENT CURRENT vs.

OUTPUT CURRENT

I OUT (mA)

I Q (m A )

SHORT CIRCUIT CURRENT I OUT (mA)

V O U T (V )

SHORT CIRCUIT CURRENT

I OUT (mA)

V O U T (V

)

DROPOUT VOLTAGE vs.OUTPUT CURRENT

I OUT (mA)

V D R O P (m

V )

DROPOUT VOLTAGE vs.OUTPUT CURRENT

I OUT (mA)

V D R O P (m V

)

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