Page 1
150
NOT RECOMMENDED
FOR NEW DESIGNS
FEATURES
■ Low Dropout Voltage
■ Low Quiescent Current
■ Very Stable Output
■ Short Circuit Protected
■ Thermal Overload Protected
■ Standard TO-92 Package
DESCRIPTION
The TK711xx is a low dropout, linear regulator housed in
a standard TO-92 package, rated at 500 mW. An internal
PNP transistor is used to achieve a low dropout voltage of
100 mV (typ.) at 30 mA load current. The TK711xx has a
low quiescent current of 130 µA (typ.) at no load. The low
quiescent current and dropout voltage make this part ideal
for battery powered applications.
TK711xx
LOW DROPOUT REGULATOR
APPLICATIONS
■ Battery Powered Systems
■ Portable Consumer Equipment
■ Cordless Telephones
■ Personal Communications Equipment
■ Radio Control Systems
■ Toys
■ Low Voltage Systems
TK711xx
1
2
3
PIN 1. OUTPUT
2. GROUND
3. INPUT
ORDERING INFORMATION
TK711
Tape/Reel Code
VoltageCode
VOLTAGE CODE
20 = 2.0 V 35 = 3.5 V
25 = 2.5 V 40 = 4.0 V
30 = 3.0 V 45 = 4.5 V
33 = 3.3 V 50 = 5.0 V
TAPE/REEL CODE
NT: Tape Left
July 2000 TOKO, Inc. Page 1
V
IN
BLOCK DIAGRAM
PROTECTION
BANDGAP
REFERENCE
THERMAL
V
GND
OUT
Page 2
TK711xx
ABSOLUTE MAXIMUM RATINGS
Input Voltage ............................................................ 15 V
Power Dissipation (Note 1) ................................ 500 mW
Operating Voltage Range............................... 1.4 to 14 V
Junction Temperature ........................................... 150 °C
TK71 120 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
Storage Temperature Range ................... -55 to +150 °C
Operating Temperature Range ...................-20 to +75 °C
Lead Soldering Temperature (10 s) ...................... 235 °C
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
Note 1: Power dissipation is 500 mW when mounted. Derate at 4 mW/°C for operation above 25 °C.
erutarepmeTtneiciffeoC51.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V0.3=
TUO
I,V9.1=
TUO
I,V0.3=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=9.10.21.2V
Am03=001002Vm
I,V0.3=
TUO
Am03=5.15.3Am
V0.31ot0.3=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
Page 2 July 2000 TOKO, Inc.
Page 3
TK71125 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3.5 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
TK711xx
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
∆V
TUO
/∆T
erutarepmeTtneiciffeoC51.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V5.3=
TUO
I,V0.2=
TUO
I,V5.3=
TUO
Am03=001002Vm
I,V5.3=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=4.25.26.2V
Am03=5.15.3Am
V5.31ot5.3=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TK71130 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.0 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
TUO
Am01=36Bd
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
erutarepmeTtneiciffeoC81.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V0.4=
TUO
I,V5.2=
TUO
I,V0.4=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=9.20.31.3V
Am03=001002Vm
I,V0.4=
TUO
Am03=5.15.3Am
V0.41ot0.4=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
July 2000 TOKO, Inc. Page 3
Page 4
TK711xx
TK71 133 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 3.9 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
erutarepmeTtneiciffeoC81.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V9.3=
TUO
I,V8.2=
TUO
I,V9.3=
TUO
Am03=001002Vm
I,V9.3=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=2.33.34.3V
Am03=5.15.3Am
V9.31ot9.3=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TK71135 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.1 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
TUO
Am01=36Bd
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
erutarepmeTtneiciffeoC2.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V1.4=
TUO
I,V0.3=
TUO
I,V1.4=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=93.305.316.3V
Am03=001002Vm
I,V1.4=
TUO
Am03=5.15.3Am
V0.41ot1.4=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
Page 4 July 2000 TOKO, Inc.
Page 5
TK71 140 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 4.6 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
TK711xx
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
erutarepmeTtneiciffeoC2.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V6.4=
TUO
I,V5.3=
TUO
I,V6.4=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=88.300.421.4V
Am03=001002Vm
I,V6.4=
TUO
Am03=5.15.3Am
V0.41ot6.4=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TK71 145 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 5.1 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
TUO
Am01=36Bd
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
/∆T
∆V
TUO
erutarepmeTtneiciffeoC52.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V1.5=
TUO
I,V0.4=
TUO
I,V1.5=
TUO
Am0=031003Aµ
Am0=4.10.3Am
Am01=63.405.446.4V
Am03=001002Vm
I,V1.5=
TUO
Am03=5.15.3Am
V0.41ot1.5=0103Vm
Am06ot1=0204Vm
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
July 2000 TOKO, Inc. Page 5
Page 6
TK711xx
TK71150 ELECTRICAL CHARACTERISTICS
Test Conditions: VIN = 5.6 V, TA = 25 °C, unless otherwise specified.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
V
I
Q
V
TUO
V
PORD
I
TUO
I
DNG
tnerruCtnecseiuQ
egatloVtuoporDI
tnerruCtuptuO001061Am
tnerruCdnuorGV
geReniLnoitalugeReniLV
geReniLnoitalugeRdaoLI
RRnoitcejeRelppiRC
∆V
/∆T
TUO
Gen Note: Parameters with min. or max. values are 100% tested at TA = 25 °C.
erutarepmeTtneiciffeoC52.0C°/Vm
NI
V
NI
egatloVtuptuOdetalugeRV
NI
TUO
NI
NI
TUO
L
I,V6.5=
TUO
I,V0.4=
TUO
I,V6.5=
TUO
Am03=001002Vm
I,V6.5=
TUO
V0.41ot6.5=0103Vm
Am06ot1=0204Vm
Am0=031003Aµ
Am0=4.10.3Am
Am01=58.400.551.5V
Am03=5.15.3Am
I,zH004=f,Fµ3.3=
TUO
Am01=36Bd
Page 6 July 2000 TOKO, Inc.
Page 7
TEST CIRCUIT
I
(
A)
NOISE
(dB)
)
TK711xx
(mV)
OUT
-10
V
30
10
50
TYPICAL PERFORMANCE CHARACTERISTICS
OUTPUT VOLTAGE
INPUT VOLTAGE
VS.
I
N
V
IN
V
IN
+
0.1
F
GND
V
OUT
+
F
3.3
I
V
OUT
OUT
TA = 25 ° C, unless otherwise specified.
m
GND
GROUND CURRENT
AMBIENT TEMPERATURE
5
4
3
2
I
OUT
I
OUT
VS.
= 60 mA
= 30 mA
500
400
300
(mV)
200
DROP
V
DROPOUT VOLTAGE
AMBIENT TEMPERATURE
I
= 60 mA
OUT
VS.
-30
-50
0 10 20
VIN (V)
NOISE SPECTRUM
-50
I
OUT
CL = 3.3 µF
-100
INSTRUMENT NOISE FLOOR
-150
0 500 1000
FREQUENCY (kHz)
= 30 mA
1
0
-50 0 50 100
TA (°C)
RIPPLE REJECTION
FREQUENCY
0
CL = 1 µF
-50
RR (dB)
CL = 10 µF
-100
100 1 k 10 k 100 k
FREQUENCY (Hz)
VS.
100
I
OUT
= 30 mA
0
-50 0 50 100
TA (°C)
LINE TRANSIENT RESPONSE
IN
V
V
OUT(TYP)
OUT
V
(20 mV / DIV)
OUT
V
V
OUT(TYP)
+ 1 V
+ 2 V
TIME (50 µs / DIV
July 2000 TOKO, Inc. Page 7
Page 8
TK711xx
I
(
A)
V
(50
V
/
DIV)
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
LOAD TRANSIENT RESPONSE
OUT
I
OUT
V
(400 mV / DIV)
OUT
V
CL = 1.0 µF
TK71120
2.05
(V)
2.00
OUT
V
I
OUT
0 mA
CL = 3.3 µF
TIME (50 µs / DIV)
OUTPUT VOLTAGE
OUTPUT CURRENT
= 30 mA
VS.
GROUND CURRENT
OUTPUT CURRENT
10
8
6
m
4
GND
2
0
0 50 100
I
(mA)
OUT
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
1
(mA)
Q
I
VS.
VS.
= 0 mA
I
m
OUT
150
(mA)
100
OUT
I
OUT
OUTPUT VOLTAGE
INPUT VOLTAGE
V
OUT(TYP)
+ 1 V
= 0 mA
VIN (100 mV / DIV)
OUTPUT CURRENT
AMBIENT TEMPERATURE
VS.
30 mA
60 mA
V
= V
IN
VS.
OUT
1.95
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
VS.
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
AMBIENT TEMPERATURE
2.05
(V)
2.00
OUT
V
1.95
-50 0 50 100
TA (°C)
VS.
Page 8 July 2000 TOKO, Inc.
Page 9
TK71125
2.55
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
OUTPUT VOLTAGE
OUTPUT CURRENT
VS.
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
VS.
150
= 0 mA
TK711xx
OUTPUT CURRENT
AMBIENT TEMPERATURE
VS.
(V)
2.50
OUT
V
2.45
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
TK71130
OUTPUT VOLTAGE
OUTPUT CURRENT
3.05
VS.
VS.
(mA)
1
Q
I
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
QUIESCENT CURRENT
INPUT VOLTAGE
2
VS.
(mA)
100
OUT
I
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
AMBIENT TEMPERATURE
2.55
(V)
2.50
OUT
V
2.45
-50 0 50 100
TA (°C)
OUTPUT CURRENT
AMBIENT TEMPERATURE
150
VS.
VS.
I
= 0 mA
OUT
(V)
3.00
OUT
V
2.95
0 50 100
I
(mA)
OUT
1
(mA)
Q
I
0
0 5 10
VIN (V)
(mA)
100
OUT
I
50
-50 0 50 100
TA (°C)
July 2000 TOKO, Inc. Page 9
Page 10
TK711xx
TK71130 (CONT.)
DROPOUT VOLTAGE
OUTPUT CURRENT
500
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
VS.
SHORT CIRCUIT PROTECTION
5
3.05
OUTPUT VOLTAGE
AMBIENT TEMPERATURE
VS.
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
TK71133
OUTPUT VOLTAGE
OUTPUT CURRENT
3.35
(V)
3.30
OUT
V
VS.
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
1
(mA)
Q
I
VS.
= 0 mA
(V)
3.00
OUT
V
2.95
-50 0 50 100
TA (°C)
OUTPUT CURRENT
AMBIENT TEMPERATURE
150
(mA)
100
OUT
I
VS.
3.25
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
VS.
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
3.35
(V)
3.30
OUT
V
3.25
AMBIENT TEMPERATURE
-50 0 50 100
TA (°C)
VS.
Page 10 July 2000 TOKO, Inc.
Page 11
TK71135
3.55
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
OUTPUT VOLTAGE
OUTPUT CURRENT
VS.
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
VS.
150
= 0 mA
TK711xx
OUTPUT CURRENT
AMBIENT TEMPERATURE
VS.
(V)
3.50
OUT
V
3.45
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
TK71140
OUTPUT VOLTAGE
OUTPUT CURRENT
4.05
VS.
VS.
1
(mA)
Q
I
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
QUIESCENT CURRENT
INPUT VOLTAGE
2
VS.
(mA)
100
OUT
I
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
3.55
(V)
3.50
OUT
V
3.45
150
AMBIENT TEMPERATURE
-50 0 50 100
TA (°C)
OUTPUT CURRENT
AMBIENT TEMPERATURE
VS.
VS.
I
= 0 mA
OUT
(V)
4.00
OUT
V
3.95
0 50 100
I
(mA)
OUT
1
(mA)
Q
I
0
0 5 10
VIN (V)
(mA)
100
OUT
I
50
-50 0 50 100
TA (°C)
July 2000 TOKO, Inc. Page 11
Page 12
TK711xx
TK71140 (CONT.)
DROPOUT VOLTAGE
OUTPUT CURRENT
500
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
VS.
SHORT CIRCUIT PROTECTION
5
4.05
OUTPUT VOLTAGE
AMBIENT TEMPERATURE
VS.
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
TK71145
OUTPUT VOLTAGE
OUTPUT CURRENT
4.55
(V)
4.50
OUT
V
VS.
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
1
(mA)
Q
I
VS.
= 0 mA
(V)
4.00
OUT
V
3.95
-50 0 50 100
TA (°C)
OUTPUT CURRENT
AMBIENT TEMPERATURE
150
(mA)
100
OUT
I
VS.
4.45
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
VS.
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
3
(V)
OUT
2
V
1
0
0 100 200
I
(mA)
OUT
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
4.55
(V)
4.50
OUT
V
4.45
AMBIENT TEMPERATURE
-50 0 50 100
TA (°C)
VS.
Page 12 July 2000 TOKO, Inc.
Page 13
TK71150
5.05
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 ° C, unless otherwise specified.
OUTPUT VOLTAGE
OUTPUT CURRENT
VS.
QUIESCENT CURRENT
INPUT VOLTAGE
2
I
OUT
VS.
150
= 0 mA
TK711xx
OUTPUT CURRENT
AMBIENT TEMPERATURE
VS.
(V)
5.00
OUT
V
4.95
0 50 100
I
(mA)
OUT
DROPOUT VOLTAGE
OUTPUT CURRENT
500
400
300
(mV)
200
DROP
V
100
0
0 50 100
I
(mA)
OUT
VS.
1
(mA)
Q
I
0
0 5 10
VIN (V)
SHORT CIRCUIT PROTECTION
5
4
(V)
3
OUT
V
2
1
0
0 100 200
I
(mA)
OUT
(mA)
100
OUT
I
50
-50 0 50 100
TA (°C)
OUTPUT VOLTAGE
5.05
(V)
5.00
OUT
V
4.95
AMBIENT TEMPERATURE
-50 0 50 100
TA (°C)
VS.
July 2000 TOKO, Inc. Page 13
Page 14
TK711xx
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 (I
GROUND CURRENT (I
GND
)
= 0 mA).
OUT
Ground current is the current which flows through the
ground pin(s). It is defined as IIN - I
DROPOUT VOLTAGE (V
DROP
)
, excluding I
OUT
CONT
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 = V
+ 1 at a chosen load current. When the
OUT
output voltage has dropped 100 mV from the nominal, V
- VO is the dropout voltage. This voltage is affected by load
current and junction temperature.
OUTPUT NOISE VOLTAGE
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 (V
OUT
x I
) increases. The rate of
OUT
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 TO-92 is
increased to 500 mW. For operation at ambient
temperatures over 25 °C, the power dissipation of the TO92 device should be derated at 4.0 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:
IN
Tj = 0jA x PD + T
A
This is the effective AC voltage that occurs on the output
voltage under the condition where the input noise is low
For Toko ICs, the internal limit for junction temperature is
150 °C. If the ambient temperature (TA) is 25 °C, then:
and with a given load, filter capacitor, and frequency
range.
150 °C = 0jA x PD + 25 °C
THERMAL PROTECTION
0jA = 125 °C / P
D
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.
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 14 July 2000 TOKO, Inc.
Page 15
TK711xx
TERMS AND DEFINITIONS (CONT.)
The range of usable currents can also be found from the
graph below.
(mW)
P
D
D
PD
Procedure:
1) Find P
2) PD1 is taken to be PD x (~ 0.8 - 0.9)
3) Plot PD1 against 25 °C
4) Connect P
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:
I
OUT
1000
800
600
(mW)
D
400
P
200
3
6
4
5
25 50 75 150
D
to the point corresponding to the 150 °C
D1
= (D
PD
0
0 50 100
TA (°C)
/ (V
IN(MAX) - VOUT
TA (°C)
)
MOUNTED
150
APPLICATION INFORMA TION
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
TK711xxN is 2.1 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).
TO-92 POWER DISSIPATION CURVE
July 2000 TOKO, Inc. Page 15
Page 16
TK711xx
PACKAGE OUTLINE
TO-92
Lot Number
0.45
+0.15
-0.05
e
M0.25
123
Marking Information
(1.4)
3.8
Marking
TK71120 120
TK71125 125
TK71130 130
TK71133 133
TK71135 135
TK71140 140
TK71145 145
TK71150 150
+0.15
-0.05
0.45
4.8
Marking
5.0
+ 0.5
13.5
e
1.271.27
Dimensions are shown in millimeters
Tolerance: x.x = ± 0.2 mm (unless otherwise specified)
R2.4
Toko America, Inc. Headquarters
1250 Feehanville Drive, Mount Prospect, Illinois 60056
Tel: (847) 297-0070 Fax: (847) 699-7864
TOKO AMERICA REGIONAL OFFICES
Midwest Regional Office
Toko America, Inc.
1250 Feehanville Drive
Mount Prospect, IL 60056
Tel: (847) 297-0070
Fax: (847) 699-7864
Western Regional Office
Toko America, Inc.
2480 North First Street , Suite 260
San Jose, CA 95131
Tel: (408) 432-8281
Fax: (408) 943-9790
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
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.
Page 16 July 2000 TOKO, Inc.
© 1999 Toko, Inc.
All Rights Reserved
IC-160-TK711xx
0798O0.0K
Printed in the USA
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