January 1999 TOKO, Inc. Page 1
TK712xx
GND
NOISE
BYPASS
VOUT
VIN
GND
NOISE
BYPASS
VIN VOUT
THERMAL
PROTECTION
BANDGAP
REFERENCE
GND
GND
APPLICATIONS
■Battery Powered Systems
■Portable Consumer Equipment
■Cordless Telephones
■Personal Communications Equipment
■Radio Control Systems
■Toys
■Low Voltage Systems
FEATURES
■Low Dropout Voltage
■Low Quiescent Current
■Very Stable Output
■Low Noise (35 µVrms)
■Miniature Package (SOT-25)
TK712xx
BLOCK DIAGRAM
DESCRIPTION
TK712xx is a low dropout, linear regulator. Since a PNP
power transistor is used, dropout voltage is very low,
making it possible to maintain stable output voltage even
as the battery decreases. This allows longer battery life.
The TK712xx has a noise bypass pin available for noise
reduction.
The TK712xx is available in a miniature SOT-25 surface
mount package.
ORDERING INFORMATION
TAPE/REEL CODE
TL: Tape Left
Tape/Reel Code
TK712 M
VoltageCode
VOLTAGE CODE
20 = 2.0 V 35 = 3.5 V
25 = 2.5 V 40 = 4.0 V
28 = 2.8 V 45 = 4.5 V
30 = 3.0 V 50 = 5.0 V
33 = 3.3 V
20P
LOW DROPOUT REGULATOR
Page 2 January 1999 TOKO, Inc.
TK712xx
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V0.3=
TUO
Am0=031003Aµ
V
NI
I,V8.1=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V0.3=
TUO
Am01=9.10.21.2V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V0.3=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.31ot0.3=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC51.0C°/Vm
TK71220 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3 V, TA = 25 °C, unless otherwise specified.
Note 1: Power dissipation is 350 mW when mounted as recommended. Derate at 2.8 mW/°C for operation above 25 °C.
ABSOLUTE MAXIMUM RATINGS
Input Voltage ............................................................ 15 V
Power Dissipation (Note 1) ................................ 350 mW
Operating Voltage Range............................... 1.4 to 14 V
Junction Temperature ...........................................150 °C
Storage Temperature Range ................... -55 to +150 °C
Operating Temperature Range ...................-30 to +80 °C
Lead Soldering Temperature (10 s) ......................235 °C
January 1999 TOKO, Inc. Page 3
TK712xx
TK71225 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3.5 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V5.3=
TUO
Am0=031003Aµ
V
NI
I,V0.2=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V5.3=
TUO
Am01=4.25.26.2V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V5.3=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V5.31ot5.3=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC51.0C°/Vm
TK71228 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3.8 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V8.3=
TUO
Am0=031003Aµ
V
NI
I,V5.2=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V8.3=
TUO
Am01=7.28.29.2V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V8.3=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V8.31ot8.3=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimretssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC81.0C°/Vm
Page 4 January 1999 TOKO, Inc.
TK712xx
TK71230 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.0 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V9.3=
TUO
Am0=031003Aµ
V
NI
I,V8.2=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V9.3=
TUO
Am01=2.33.34.3V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V9.3=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot9.3=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC81.0C°/Vm
TK71233 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3.9 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V0.4=
TUO
Am0=031003Aµ
V
NI
I,V5.2=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V0.4=
TUO
Am01=9.20.31.3V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V0.4=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot0.4=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC81.0C°/Vm
January 1999 TOKO, Inc. Page 5
TK712xx
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V1.4=
TUO
Am0=031003Aµ
V
NI
I,V0.3=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V1.4=
TUO
Am01=93.305.316.3V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V1.4=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot1.4=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC2.0C°/Vm
TK71235 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.1 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V6.4=
TUO
Am0=031003Aµ
V
NI
I,V5.3=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V6.4=
TUO
Am01=88.300.421.4V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V6.4=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot6.4=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC2.0C°/Vm
TK71240 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.6 V, TA = 25 °C, unless otherwise specified.
Page 6 January 1999 TOKO, Inc.
TK712xx
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V6.5=
TUO
Am0=031003Aµ
V
NI
I,V0.4=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V6.5=
TUO
Am01=58.400.551.5V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V6.5=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot6.5=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC52.0C°/Vm
TK71245 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 5.1 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQ V
NI
I,V1.5=
TUO
Am0=031003Aµ
V
NI
I,V0.4=
TUO
Am0=4.10.3Am
V
TUO
egatloVtuptuOdetalugeRV
NI
I,V1.5=
TUO
Am01=63.405.446.4V
V
PORD
egatloVtuoporDI
TUO
Am03=001002Vm
I
TUO
tnerruCtuptuO001061Am
I
DNG
tnerruCdnuorGV
NI
I,V1.5=
TUO
Am03=5.15.3Am
geReniLnoitalugeReniLV
NI
V0.41ot1.5=0103Vm
geRdaoLnoitalugeRdaoLI
TUO
Am06ot1=0204Vm
RRnoitcejeRelppiRC
L
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
V
fer
lanimreTssapyBesioN egatloV 72.1V
∆V
TUO
/∆TerutarepmeTtneiciffeoC52.0C°/Vm
TK71250 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 5.6 V, TA = 25 °C, unless otherwise specified.
January 1999 TOKO, Inc. Page 7
TK712xx
TEST CIRCUIT
VIN
NOISE
BYPASS
VOUT
VIN
IIN
+
GND
+
VOUT
IOUT
CL
CN
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25 ° C, unless otherwise specified.
VOUT (mV)
50
OUTPUT VOLTAGE
VS.
INPUT VOLTAGE
VIN (V)
0 10 20
-50
30
10
-10
-30
I
GND
(
m
A)
5
GROUND CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
0
4
3
2
1
IOUT = 60 mA
IOUT = 30 mA
VDROP (mV)
500
DROPOUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
0
400
300
200
100
IOUT = 60 mA
IOUT = 30 mA
NOISE
(dB)
-50 NOISE SPECTRUM
FREQUENCY (kHz)
0 500 1000
-100
-150
IOUT = 30 mA
INSTRUMENT NOISE FLOOR
CN = 0.01 µF
CL = 1 µF
RR (dB)
0
RIPPLE REJECTION VS.
FREQUENCY
FREQUENCY (Hz)
100 1 k 10 k 100 k
-50
-100
CL = 1 µF
CL = 10 µF
NOISE
(
µ
V)
300
NOISE VOLTAGE
VS.
BYPASS CAPACITOR
CN
1 pF 10 pF 100 pF 1000 pF 0.01 µF.1 µF
100
IOUT = 30 mA
200
150
50
0
CL = 3.3 µF
CL = 1.0 µF
CL = 10 µF
CL = 10 µF
VOUT = 2 V
VOUT = 5 V
Page 8 January 1999 TOKO, Inc.
TK712xx
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
VOUT
LOAD TRANSIENT RESPONSE
IOUT
VOUT (400 mV / DIV)
IOUT = 30 mA
0 mA
CL = 3.3 µF
CL = 1.0 µF
TIME (50 µs / DIV)
I
GND
(
m
A)
10
GROUND CURRENT VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
8
6
4
2
V
OUT
(
5
0
m
V
/
DIV)
OUTPUT VOLTAGE VS.
INPUT VOLTAGE
VIN (100 mV / DIV)
IOUT = 0 mA 30 mA
60 mA
VIN = VOUT
VOUT(TYP) + 1 V
VOUT
LINE TRANSIENT RESPONSE
VIN
VOUT (20 mV / DIV)
VOUT(TYP) + 2 V
TIME
(
50
µ
s / DIV
)
VOUT(TYP) + 1 V
January 1999 TOKO, Inc. Page 9
TK712xx
TK71225
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
TK71220
VOUT (V)
2.05
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
1.95
2.00
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
2.05
OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
1.95
2.00
VOUT (V)
2.55
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
2.45
2.50
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
Page 10 January 1999 TOKO, Inc.
TK712xx
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
TK71225 (CONT.)
TK71228
VDROP (mV)
500
DROPOUT VOLTAGE VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
2.55
OUTPUT VOLTAGE
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
2.45
2.50
VOUT (V)
2.85
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
2.75
2.80
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
2.85
OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
2.75
2.80
January 1999 TOKO, Inc. Page 11
TK712xx
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
TK71230
TK71233
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
3.05
OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
2.95
3.00
VOUT (V)
3.35
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
3.25
3.30
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VOUT (V)
3.05
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
2.95
3.00
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
Page 12 January 1999 TOKO, Inc.
TK712xx
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
TK71233 (CONT.)
TK71235
VDROP (mV)
500
DROPOUT VOLTAGE VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
3.35
OUTPUT VOLTAGE
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
3.25
3.30
VOUT (V)
3.55
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
3.45
3.50
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
3.55
OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
3.45
3.50
January 1999 TOKO, Inc. Page 13
TK712xx
TK71240
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
TK71245
VOUT (V)
4.05
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
3.95
4.00
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
4.05
OUTPUT VOLTAGE
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
3.95
4.00
VOUT (V)
4.55
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
4.45
4.50
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
Page 14 January 1999 TOKO, Inc.
TK712xx
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
VOUT (V)
5.05
OUTPUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
4.95
5.00
IQ (mA)
2
QUIESCENT CURRENT
VS.
INPUT VOLTAGE
VIN (V)
0 5 10
0
1
IOUT = 0 mA
IOUT (mA)
150
OUTPUT CURRENT
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
50
100
VDROP (mV)
500
DROPOUT VOLTAGE
VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5
SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
5.05
OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
4.95
5.00
VDROP (mV)
500
DROPOUT VOLTAGE VS.
OUTPUT CURRENT
IOUT (mA)
0 50 100
0
200
400
300
100
VOUT (V)
5SHORT CIRCUIT PROTECTION
IOUT (mA)
0 100 200
0
2
4
3
1
VOUT (V)
4.55
OUTPUT VOLTAGE
VS.
AMBIENT TEMPERATURE
TA (°C)
-50 0 50 100
4.45
4.50
TK71245 (CONT.)
TK71250
January 1999 TOKO, Inc. Page 15
TK712xx
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
LINE REGULATION (LINE REG)
Line regulation is the ability of the regulator to maintain a
constant output voltage as the input voltage changes.
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.
The load regulation is specified an output current step
condition of 1 mA to 60 mA.
QUIESCENT CURRENT (IQ)
The quiescent current is the current which flows through
the ground terminal under no load conditions (IOUT = 0 mA).
GROUND CURRENT (IGND)
Ground current is the current which flows through the
ground pin(s). It is defined as IIN - IOUT, excluding ICONT.
DROPOUT VOLTAGE (VDROP)
This is a measure of how well the regulator performs as the
input voltage decreases. The smaller the number, the
further the input voltage can decrease before regulation
problems occur. Nominal output voltage is first measured
when VIN = VOUT + 1 at a chosen load current. When the
output voltage has dropped 100 mV from the nominal, VIN
- VO is the dropout voltage. This voltage is affected by load
current and junction temperature.
OUTPUT NOISE VOLTAGE
This is the effective AC voltage that occurs on the output
voltage under the condition where the input noise is low
and with a given load, filter capacitor, and frequency
range.
THERMAL PROTECTION
This is an internal feature which turns the regulator off
when the junction temperature rises above 150 °C. After
the regulator turns off, the temperature drops and the
regulator output turns back on. Under certain conditions,
the output waveform may appear to be an oscillation as the
output turns off and on and back again in succession.
PACKAGE POWER DISSIPATION (PD)
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 (VIN x IIN)
and the output power (VOUT x IOUT) 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 mounting pad, the power dissipation of the SOT-25 is
increased to 350 mW. For operation at ambient
temperatures over 25 °C, the power dissipation of the
SOT-25 device should be derated at 2.8 mW/°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 PD /(150 °C - TA) 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:
Tj = 0jA x PD + TA
For Toko ICs, the internal limit for junction temperature is
150 °C. If the ambient temperature (TA) is 25 °C, then:
150 °C = 0jA x PD + 25 °C
0jA = 125 °C / PD
PD is the value when the thermal sensor is activated. A
simple way to determine PD is to calculate VIN x IIN when
the output side is shorted. Input current gradually falls as
temperature rises. You should use the value when thermal
equilibrium is reached.
Page 16 January 1999 TOKO, Inc.
TK712xx
DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)
The range of usable currents can also be found from the
graph below.
Procedure:
1) Find PD
2) PD1 is taken to be PD x (~ 0.8 - 0.9)
3) Plot PD1 against 25 °C
4) Connect PD1 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 PD against the point at which the
vertical line intersects the derating curve. This is taken
as the maximum power dissipation, DPD.
The maximum operating current is:
IOUT = (DPD / (VIN(MAX) - VOUT)
PD
DPD
25 50 75 150
(mW)
TA (°C)
3
6
5
4
0 50 100
TA (°C)
PD (mW)
150
0
600
1000
200
400
800
MOUNTED
FREE AIR
SOT-25 POWER DISSIPATION CURVE
January 1999 TOKO, Inc. Page 17
TK712xx
INPUT/OUTPUT DECOUPLING CAPACITOR
CONSIDERATIONS
Voltage regulators require input and output decoupling
capacitors. The required value of these capacitors vary
with application. Capacitors made by different
manufacturers can have different characteristics,
particularly with regard to high frequencies and Equivalent
Series Resistance (ESR) over temperature. The type of
capacitor is also important. For example, a 4.7 µF aluminum
electrolytic may be required for a certain application. If a
tantalum capacitor is used, a lower value of 2.2 µF would
be adequate. It is important to consider the temperature
characteristics of the decoupling capacitors. While Toko
regulators are designed to operate as low as -40 °C, many
capacitors will not operate properly at this temperature.
The capacitance of aluminum electrolytic capacitors may
decrease to 0 at low temperatures. This may cause
oscillation on the output of the regulator since some
capacitance is required to guarantee stability. Thus, it is
important to consider the characteristics of the capacitor
over temperature when selecting decoupling capacitors.
The ESR is another important parameter. The ESR will
increase with temperature but low ESR capacitors are
often larger and more costly. In general, tantalum capacitors
offer lower ESR than aluminum electrolytic, but new low
ESR aluminum electrolytic capacitors are now available
from several manufacturers. Usually a bench test is
sufficient to determine the minimum capacitance required
for a particular application. After taking thermal
characteristics and tolerance into account, the minimum
capacitance value should be approximately two times this
value. The recommended minimum capacitance for the
TK712xx is 2.2 µF for a tantalum capacitor or 3.3 µF for an
aluminum electrolytic. Please note that linear regulators
with a low dropout voltage have high internal loop gains
which require care in guarding against oscillation caused
by insufficient decoupling capacitance. The use of high
quality decoupling capacitors suited for your application
will guarantee proper operation of the circuit. Pay attention
to temperature characteristics of the capacitor, especially
the increase of ESR and decrease of capacitance in low
temperatures. Oscillation, reduction of ripple rejection and
increased noise may occur in some cases if the proper
capacitor is not used. An output capacitor more than 1.0 µF
is required to maintain stability. The standard test condition
is 3.3 µF (TA = 25 °C).
APPLICATION INFORMATION
OPTIMUM PERFORMANCE
Optimum performance can only be achieved when the IC
is mounted on a PC board according to the diagram below.
This is because of the extremely small package and limited
power dissipation. Shape the metal portion of the PCB as
shown in the following drawing.
SOT-25 BOARD LAYOUT
Use a large bypass capacitor and connect it in a place near
GND of the IC. Pay attention to temperature characteristics
of the capacitor, especially the increase of ESR and
decrease of capacitance in low temperatures. Oscillation,
reduction of ripple rejection and increased noise may
occur in some cases if the proper capacitor is not used. An
output capacitor more than 1.0 µF is required to maintain
stability. The standard test condition is 3.3 µF (TA = 25 °C).
++
GND
CN
VIN VOUT
GND
+
Page 18 January 1999 TOKO, Inc.
TK712xx
Marking Information
Marking
TK71220 J20
TK71225 J25
TK71228 J28
TK71230 J30
TK71233 J33
TK71235 J35
TK71240 J40
TK71245 J45
TK71250 J50
SOT-25 (SOT-23-5)
PACKAGE OUTLINE
Printed in the USA
© 1999 Toko, Inc.
All Rights Reserved
TOKO AMERICA REGIONAL OFFICES
Toko America, Inc. Headquarters
1250 Feehanville Drive, Mount Prospect, Illinois 60056
Tel: (847) 297-0070 Fax: (847) 699-7864
IC-161-TK712xx
0798O0.0K
Visit our Internet site at http://www.tokoam.com
The information furnished by TOKO, Inc. is believed to be accurate and reliable. However, TOKO reserves the right to make changes or improvements in the design, specification or manufacture of its
products without further notice. TOKO does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of
third parties which may result from the use of its products. No license is granted by implication or otherwise under any patent or patent rights of TOKO, Inc.
0.95 0.95
0.95
0.95
e
M
0.1
2.9
1.6
1.1
0.16
0.4
2.8
1.90
2.4
e'
Recommended Mount Pad
123
4
5
1.0
0.7
(0.8)
0 - 0.1 (0.6)
(0.6)
1.3 max
e
ee
0.1
e1
15 max
Marking
0.3
+0.1
+0.15
- 0.05
Dimensions are shown in millimeters
Tolerance: x.x = 0.2 mm
(
unless otherwise specified
)
+0.15
- 0.05
+0.2
- 0.3
Western Regional Office
Toko America, Inc.
2480 North First Street , Suite 260
San Jose, CA 95131
Tel: (408) 432-8281
Fax: (408) 943-9790
Midwest Regional Office
Toko America, Inc.
1250 Feehanville Drive
Mount Prospect, IL 60056
Tel: (847) 297-0070
Fax: (847) 699-7864
Eastern Regional Office
Toko America, Inc.
107 Mill Plain Road
Danbury, CT 06811
Tel: (203) 748-6871
Fax: (203) 797-1223
Semiconductor Technical Support
Toko Design Center
4755 Forge Road
Colorado Springs, CO 80907
Tel: (719) 528-2200
Fax: (719) 528-2375
