Page 1
March 1999 TOKO, Inc. Page 1
TK111xxS
FEATURES
■ High Voltage Precision at ± 2.0% or ± 60 mV
■ Active High On/Off Control
■ Very Low Dropout Voltage (85 mV at 30 mA)
■ Very Low Noise
■ Miniature Package (SOT-23-5)
■ Internal Thermal Shutdown
■ Short Circuit Protection
■ Excellent Ripple Rejection (70 dB @ 1 kHz)
■ Reverse Bias Protection
APPLICATIONS
■ Battery Powered Systems
■ Cellular Telephones
■ Pagers
■ Personal Communications Equipment
■ Portable Instrumentation
■ Portable Consumer Equipment
■ Radio Control Systems
■ Toys
BLOCK DIAGRAM
TK111xxS
DESCRIPTION
The TK111xxS is a low dropout linear regulator with a builtin electronic switch. The internal switch can be controlled
by TTL or CMOS logic levels. The device is in the “on” state
when the control pin is pulled to a logic high level. An
external capacitor can be connected to the noise bypass
pin to lower the output noise level to 30 µVrms.
An internal PNP pass transistor is used to achieve a low
dropout voltage of 85 mV (typ.) at 30 mA load current. The
TK111xxS has a very low quiescent current of 140 µA
(typ.) at no load . The standby current is 100 nA maximum.
The internal thermal shut down circuitry limits the junction
temperature to below 150 °C. The load current is internally
monitored and the device will shut down in the presence of
a short circuit or overcurrent condition at the output.
The TK111xxS is available in a miniature SOT-23-5 surface
mount package.
TK111 S L
ORDERING INFORMATION
TAPE/REEL CODE
L: Tape Left
PACKAGE CODE
S: SOT-23-5
Tape/Reel Code
Voltage Code
VOLTAGE CODE
20 = 2.0 V 32 = 3.2 V 43 = 4.3 V
21 = 2.1 V 33 = 3.3 V 44 = 4.4 V
22 = 2.2 V 34 = 3.4 V 45 = 4.5 V
23 = 2.3 V 35 = 3.5 V 46 = 4.6 V
24 = 2.4 V 36 = 3.6 V 47 = 4.7 V
25 = 2.5 V 37 = 3.7 V 48 = 4.8 V
27 = 2.7 V 38 = 3.8 V 49 = 4.9 V
28 = 2.8 V 39 = 3.9 V 50 = 5.0 V
29 = 2.9 V 40 = 4.0 V
30 = 3.0 V 41 = 4.1 V
31 = 3.1 V 42 = 4.2 V
Package Code
Temp. Code
Note 1:
2.0 to 2.3 V
available in C
temperature code
(-30 to +80 °C) only
TEMP. CODE
C: -30 to +80 °C
I: -40 to +85 °C
20P
GND
CONTROL
V
OUT
V
IN
NOISE BYPASS
NOISE
BYPASS
V
IN
V
OUT
THERMAL
PROTECTION
BANDGAP
REFERENCE
CONTROL
GND
5
VOLTAGE REGULATOR WITH ON/OFF SWITCH
Page 2
Page 2 March 1999 TOKO, Inc.
TK111xxS
ABSOLUTE MAXIMUM RATINGS TK111xxSCL
Supply Voltage ......................................................... 16 V
Control Terminal Voltage ......................................... 12 V
Noise Bypass Terminal Voltage ................................. 5 V
Power Dissipation (Note 1) ................................ 500 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 12 V
Junction Temperature ........................................... 150 °C
Lead Soldering Temperature (10 s) ...................... 235 °C
TK111xxSCL ELECTRICAL CHARACTERISTICS
Test conditions: VIN = V
OUT(TYP)
+ 1 V, TA = 25 °C, unless otherwise specified.
Note 1: Power dissipation is 500 mW when mounted as recommended. Derate at 4.0 mW/°C 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 the noise bypass terminal.
Gen. Note: Parameters with min. or max. values are 100% tested at TA = 25 °C.
Gen. Note: Exceeding the “Absolute Maximum Ratings” can damage the device.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQI
TUO
IgnidulcxE,Am0=
TNOC
041002Aµ
I
YBTS
tnerruCybdnatSV
NI
V,FFOtuptuO,V6=
TNOC
≤ V51.01.0Aµ
V
TUO
egatloVtuptuOI
TUO
V,Am01=
NI
V=
)PYT(TUO
V1+1elbaTeeSV
geReniLnoitalugeReniL
V
NI
V=
)PYT(TUO
otV1+
V
)PYT(TUO
)2etoN(,V6+
8.081Vm
geRdaoLnoitalugeRdaoL
I
TUO
)2etoN(,Am06ot1=803Vm
I
TUO
)2etoN(,Am001ot1=4155Vm
V
PORD
egatloVtuoporDI
TUO
)2etoN(,Am06=021002Vm
I
TUO
tnerruCtuptuOsuounitnoC)2etoN(001Am
I
)ESLUP(TUO
tnerruCtuptuOesluP
etoN(,elcycytud%5.21,eslupsm5
)2
031Am
RRnoitcejeRelppiR
C,zHk1=f
L
,Fµ7.4=
C
N
V,Fµ1.0=
NI
V=
)PYT(TUO
V,V2+
R
=
I,smrVm002
TUO
setoN(,Am01=
)4,3
07Bd
V
ON
egatloVesioNtuptuO
zH004 ≤ f ≤ C,zHk08
L
,Fµ7.4=
C
N
V,Fµ10.0=
NI
V=
)PYT(TUO
,V2+
I
TUO
)4,3setoN(,Am01=
03smrVµ
V
fer
lanimreTssapyBesioN
egatloV
52.1V
∆V
TUO
/∆T
tneiciffeoCerutarepmeTI
TUO
Am01=52C°/mpp
SNOITACIFICEPSLANIMRETLORTNOC
I
TNOC
tnerruClortnoCV
TNOC
NOtuptuO,V8.1=2.14 Aµ
V
)NO(TNOC
NOegatloVlortnoCNOtuptuO5.1V
V
)FFO(TNOC
FFOegatloVlortnoCFFOtuptuO53.0V
Page 3
March 1999 TOKO, Inc. Page 3
TK111xxS
ABSOLUTE MAXIMUM RATINGS TK111xxSIL (V
OUT
≥ 2.4 V)
Supply Voltage ......................................................... 15 V
Control Terminal Voltage ......................................... 12 V
Noise Bypass Terminal Voltage ................................. 5 V
Power Dissipation (Note 1) ................................ 500 mW
Reverse Bias............................................................ 10 V
TK111xxSIL ELECTRICAL CHARACTERISTICS (V
OUT
≥ 2.4 V)
Test conditions: VIN = V
OUT(TYP)
+ 1 V, TA = -40 to +85 °C, unless otherwise specified.
Note 1: Power dissipation is 500 mW when mounted as recommended. Derate at 4.0 mW/°C 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 the noise bypass terminal.
Gen. Note: Parameters with min. or max. values are 100% tested at TA = 25 °C.
Gen. Note: Exceeding the “Absolute Maximum Ratings” can damage the device.
LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU
I
Q
tnerruCtnecseiuQI
TUO
IgnidulcxE,Am0=
TNOC
041002Aµ
I
YBTS
tnerruCybdnatSV
NI
V,FFOtuptuO,V6=
TNOC
≤ V51.02.0Aµ
V
TUO
egatloVtuptuOI
TUO
V,Am01=
NI
V=
)PYT(TUO
V1+2elbaTeeSV
geReniLnoitalugeReniL
V
NI
V=
)PYT(TUO
otV1+
V
)PYT(TUO
)2etoN(,V6+
8.081Vm
geRdaoLnoitalugeRdaoL
I
TUO
)2etoN(,Am06ot1=803Vm
I
TUO
)2etoN(,Am001ot1=4155Vm
V
PORD
egatloVtuoporDI
TUO
)2etoN(,Am06=021002Vm
I
TUO
tnerruCtuptuOsuounitnoC)2etoN(001Am
I
)ESLUP(TUO
tnerruCtuptuOesluP
etoN(,elcycytud%5.21,eslupsm5
)2
031Am
RRnoitcejeRelppiR
C,zHk1=f
L
,Fµ7.4=
C
N
V,Fµ1.0=
NI
V=
)PYT(TUO
V,V2+
R
=
I,smrVm002
TUO
setoN(,Am01=
)4,3
07Bd
V
ON
egatloVesioNtuptuO
zH004 ≤ f ≤ C,zHk08
L
,Fµ7.4=
C
N
V,Fµ10.0=
NI
V=
)PYT(TUO
,V2+
I
TUO
)4,3setoN(,Am01=
03smrVµ
V
fer
lanimreTssapyBesioN
egatloV
52.1V
∆V
TUO
/∆T
tneiciffeoCerutarepmeTI
TUO
Am01=52C°/mpp
SNOITACIFICEPSLANIMRETLORTNOC
I
TNOC
tnerruClortnoCV
TNOC
NOtuptuO,V8.1=2.16 Aµ
V
)NO(TNOC
NOegatloVlortnoCNOtuptuO5.1V
V
)FFO(TNOC
FFOegatloVlortnoCFFOtuptuO53.0V
Storage Temperature Range ................... -55 to +150 °C
Operating Temperature Range ...................-40 to +85 °C
Operating Voltage Range............................... 2.0 to 12 V
Junction Temperature ........................................... 150 °C
Lead Soldering Temperature (10 s) ...................... 235 °C
Page 4
Page 4 March 1999 TOKO, Inc.
TK111xxS
TK111xxSCL ELECTRICAL CHARACTERISTICS TABLE 1
Output Voltage V
OUT(MIN)
V
OUT(MAX)
Test
Voltage Code Voltage
2.0 V 20 1.940 V 2.060 V 3.0 V
2.1 V 21 2.040 V 2.160 V 3.1 V
2.2 V 22 2.140 V 2.260 V 3.2 V
2.3 V 23 2.240 V 2.360 V 3.3 V
2.4 V 24 2.340 V 2.460 V 3.4 V
2.5 V 25 2.440 V 2.560 V 3.5 V
2.7 V 27 2.640 V 2.760 V 3.7 V
2.8 V 28 2.740 V 2.860 V 3.8 V
2.9 V 29 2.840 V 2.960 V 3.9 V
3.0 V 30 2.940 V 3.060 V 4.0 V
3.1 V 31 3.038 V 3.162 V 4.1 V
3.2 V 32 3.136 V 3.264 V 4.2 V
3.3 V 33 3.234 V 3.366 V 4.3 V
3.4 V 34 3.232 V 3.468 V 4.4 V
3.5 V 35 3.430 V 3.570 V 4.5 V
Output Voltage V
OUT(MIN)
V
OUT(MAX)
Test
Voltage Code Voltage
3.6 V 36 3.528 V 3.672 V 4.6 V
3.7 V 37 3.626 V 3.774 V 4.7 V
3.8 V 38 3.724 V 3.876 V 4.8 V
3.9 V 39 3.822 V 3.978 V 4.9 V
4.0 V 40 3.920 V 4.080 V 5.0 V
4.1 V 41 4.018 V 4.182 V 5.1 V
4.2 V 42 4.116 V 4.284 V 5.2 V
4.3 V 43 4.214 V 4.386 V 5.3 V
4.4 V 44 4.312 V 4.488 V 5.4 V
4.5 V 45 4.410 V 4.590 V 5.5 V
4.6 V 46 4.508 V 4.692 V 5.6 V
4.7 V 47 4.606 V 4.794 V 5.7 V
4.8 V 48 4.704 V 4.896 V 5.8 V
4.9 V 49 4.802 V 4.988 V 5.9 V
5.0 V 50 4.900 V 5.100 V 6.0 V
Page 5
March 1999 TOKO, Inc. Page 5
TK111xxS
TK111xxSIL ELECTRICAL CHARACTERISTICS TABLE 2
Test Conditions: VIN = V
OUT(TYP)
+ 1 V, I
OUT
= 30 mA, unless otherwise specified.
Room Temp. Range (TA = 25 °C) Full Temp. Range (TA = -40 to +85 °C)
Output Voltage V
OUT(MIN)
V
OUT(MAX)
V
OUT(MIN)
V
OUT(MAX)
Voltage Code
2.4 V 24 2.340 V 2.460 V 2.305 V 2.495 V
2.5 V 25 2.440 V 2.560 V 2.405 V 2.595 V
2.7 V 27 2.640 V 2.760 V 2.605 V 2.795 V
2.8 V 28 2.740 V 2.860 V 2.705 V 2.895 V
2.9 V 29 2.840 V 2.960 V 2.805 V 2.995 V
3.0 V 30 2.940 V 3.060 V 2.905 V 3.095 V
3.1 V 31 3.038 V 3.162 V 3.007 V 3.193 V
3.2 V 32 3.136 V 3.264 V 3.104 V 3.296 V
3.3 V 33 3.234 V 3.366 V 3.201 V 3.400 V
3.4 V 34 3.332 V 3.468 V 3.298 V 3.502 V
3.5 V 35 3.430 V 3.570 V 3.395 V 3.605 V
3.6 V 36 3.528 V 3.672 V 3.492 V 3.708 V
3.7 V 37 3.626 V 3.774 V 3.589 V 3.811 V
3.8 V 38 3.724 V 3.876 V 3.686 V 3.914 V
3.9 V 39 3.822 V 3.988 V 3.783 V 4.017 V
4.0 V 40 3.920 V 4.080 V 3.880 V 4.120 V
4.1 V 41 4.018 V 4.182 V 3.977 V 4.223 V
4.2 V 42 4.116 V 4.284 V 4.074 V 4.326 V
4.3 V 43 4.214 V 4.366 V 4.171 V 4.429 V
4.4 V 44 4.312 V 4.488 V 4.268 V 4.532 V
4.5 V 45 4.410 V 4.590 V 4.365 V 4.635 V
4.6 V 46 4.598 V 4.692 V 4.462 V 4.738 V
4.7 V 47 4.696 V 4.794 V 4.559 V 4.841 V
4.8 V 48 4.794 V 4.896 V 4.656 V 4.944 V
4.9 V 49 4.892 V 4.998 V 4.753 V 5.047 V
5.0 V 50 4.900 V 5.100 V 4.850 V 5.150 V
Page 6
Page 6 March 1999 TOKO, Inc.
TK111xxS
I
OUT
I
CONT
CONT
V
CONT
C
IN
1 µF
I
IN
NOISE BYPASS
V
IN
C
L
2.2 µF
TANTALUM
ESR = 1.6 Ω
CN = 0.0047 µF
V
IN
V
OUT
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25 °C, unless otherwise specified.
TEST CIRCUIT
V
OUT
(
5 m
V/
DIV)
LOAD REGULATION
I
OUT
(mA)
0 50 100
V
OUT
TYPICAL
V
OUT
(V)
SHORT CIRCUIT CURRENT
I
OUT
(mA)
0 150 300
5
4
3
2
1
0
V
OUT
(25 mV/ DIV)
OUTPUT VOLTAGE
VS.
INPUT VOLTAGE
VIN (V) (50 mV/ DIV)
0 VIN = V
OUT
I
OUT
= 30 mA
I
OUT
= 60 mA
I
OUT
= 90 mA
I
OUT
= 0 mA
V
OUT
TYPICAL
V
OUT
(
5
0
m
V/
DIV)
LINE REGULATION
VIN (V)
0 10 20
V
OUT
TYPICAL
V
DROP
(mV)
DROPOUT VOLTAGE VS.
OUTPUT CURRENT
I
OUT
(mA)
0 100 200
0
-100
-200
-300
-400
-500
I
GND
(mA)
GROUND CURRENT VS.
OUTPUT CURRENT
I
OUT
(mA)
0 75 150
10
8
6
4
2
0
Page 7
March 1999 TOKO, Inc. Page 7
TK111xxS
I
REV
(µA)
REVERSE BIAS CURRENT
(VIN = 0 V)
V
REV
(V)
0 10 20
500
400
300
200
100
0
I
STBY
(pA)
STANDBY CURRENT (OFF MODE)
VS. INPUT VOLTAGE
V
IN
(V)
0 10 20
100
50
0
I
Q
(mA)
QUIESCENT CURRENT (ON MODE)
VS.
INPUT VOLTAGE
V
IN
(V)
0 5 10
2
1
0
I
OUT
= 0 mA
V
OUT
= 3 V
I
CONT
(µA)
CONTROL CURRENT
VS.
CONTROL VOLTAGE
V
CONT
(V)
0 1 2 3 4 5
10
6
0
8
4
2
V
OUT
I
GND
(mA)
GROUND CURRENT
TA (°C)
-50 0 50 100
2
0
1
I
OUT
= 60 mA
I
OUT
= 30 mA
V
DROP
(mV)
DROPOUT VOLTAGE
TA (°C)
-50 0 50 100
200
0
100
I
OUT
= 60 mA
I
OUT
= 30 mA
I
OUT
= 100 mA
I
CONT
(µA)
CONTROL CURRENT
TA (°C)
-50 0 50 100
8
0
6
10
4
2
V
CONT
= 5 V
V
CONT
= 1.8 V
V
CONT
(V)
V
CONT
(V
OUT
, ON POINT)
TA (°C)
-50 0 50 100
2
0
1
R
CONT
= 0 Ω
I
OUT
(mA)
MAXIMUM OUTPUT CURRENT
TA (°C)
-50 0 50 100
260
220
230
250
240
V
OUT
= 2.7 V
OR ABOVE
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
Page 8
Page 8 March 1999 TOKO, Inc.
TK111xxS
∆V
OUT
(mV)
OUTPUT VOLTAGE VARIATION
TA (°C)
-50 0 50 100
20
-20
-10
10
0
-30
2.8 V
3.0 V
NOISE (µV)
OUTPUT NOISE LEVEL
VS.
C
N
C
N
1 pF 10 100 1000 0.1 µF .1
250
200
150
100
50
0
CL = 2.2 µF
I
OUT
= 60 mA
CL = 10 µF
CL = 3.3µF
dB
NOISE SPECTRUM
f (Hz)
0 500 k 1 M
0
-50
-100
CL = 3.3 µF, CN = NONE
CL = 3.3 µF, CN = 0.1 µF
SPECTRUM ANALYZER BACK-
GROUND NOISE
V
OUT
(10
m
V/
DIV)
LINE VOLTAGE STEP RESPONSE
TIME (µs)
0 100 200 300 400
V
IN
CN = 0.001 µF
CN = 0.01 µF
V
OUT
+2 V
V
OUT
+1 V
V
OUT
(
5
0
m
V/
DIV)
LOAD CURRENT STEP RESPONSE 1
TIME (µs)
0 200 400 600 800
I
OUT
5 TO 100 mA
CL = 2.2 µF
CN = 0.01 µF
1 TO 100 mA
100 mA
1 OR 5 mA
V
OUT
(10
m
V/
DIV)
LOAD CURRENT STEP RESPONSE 2
TIME (ms)
0 2 4 6 8
I
OUT
CN = 0.01 µF50 mA
0 mA
CL = 2.2 µF
CL = 4.7 µF
CL = 10 µF
CL = 47 µF
RR (dB)
RIPPLE REJECTION
f (kHz)
0.01 1 10 100
0
-20
-40
-60
-80
-100
CL = 4.7 µF, CN = 1.0 µF
CL = 2.2 µF, CN = .01 µF
CL = 4.7 µF, CN = 0.1 µF
I
OUT
= 30 mA
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
Page 9
March 1999 TOKO, Inc. Page 9
TK111xxS
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
OUTPUT VOLTAGE (V
OUT
)
The output voltage is specified with VIN = (V
OUT(TYP)
+ 1 V)
and I
OUT
= 10 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)
)
The rated output current is specified under the condition
where the output voltage drops 0.3 V below the value
specified with I
OUT
= 10 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 the
package power dissipation.
PULSE OUTPUT CURRENT (I
OUT (PULSE)
)
Max pulse width 5 ms, 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 VIN = V
OUT(TYP)
+ 1 V to VIN = 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 VIN = V
OUT(TYP)
+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 (IQ)
The quiescent current is the current which flows through
the ground terminal under no load conditions (I
OUT
= 0 mA).
GROUND CURRENT
Ground current is the current which flows through the
ground pin(s). It is defined as IIN - I
OUT
, excluding control
current.
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 200 mVrms, 1 kHz superimposed on the
input voltage, where VIN = V
OUT
+ 2 V. The output decoupling
capacitor is set to 4.7 µF, the noise bypass capacitor is set
to 0.01 µF, 0.1 µF, 1.0 µF and the load current is set to
10 mA. Ripple rejection is the ratio of the ripple content of
the output vs. the input and is expressed in dB.
Example: 64 dB at CN = 0.01 µF, 70 dB at
CN = 0.1 µF, 74 dB at CN = 1.0 µF.
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 VIN = 6 V.
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 (Tj = 150
°C). This temperature rise can be caused by extreme heat,
excessive power dissipation caused by large output voltage
drops, or excessive output current. The regulator will shut
off when the temperature exceeds the safe value. As the
junction temperature decreases, 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 10
Page 10 March 1999 TOKO, Inc.
TK111xxS
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.
REDUCTION OF OUTPUT NOISE
Although the architecture of the Toko regulators is designed
to minimize semiconductor noise, further reduction can be
achieved by the selection of external components. The
obvious solution is to increase the size of the output
capacitor. A more effective solution would be to add a
capacitor to the noise bypass terminal. The value of this
capacitor should be 0.1 µF or higher (higher values provide
greater noise reduction). Although stable operation is
possible without the noise bypass capacitor, this terminal
has a high impedance and care should be taken to avoid
a large circuit area on the printed circuit board when the
capacitor is not used. Please note that several parameters
are affected by the value of the capacitors and bench
testing is recommended when deviating from standard
values.
CONTROL FUNCTION
The TK111xxS has an active high control pin. The control
pin requires over 1.8 V for operation and under
0.6 V for
standby. For the range of 0.6 V < V
CONT
< 1.8 V
, operation
is undefined. If the control function is not used, connect the
control pin to VIN.
DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)
SW
C
N
V
IN
OUTPUT VOLTAGE RESPONSE A
(OFF→ON)
-5 5 2515 35
CL = 0.47µF
45
CL = 0.68 µF
CL = 1.5 µF
CL = 1.0 µF
TIME (µs)
I
LOAD
= 30 mA, CN = 3300 pF
V
OUT
V
CONT
OUTPUT VOLTAGE RESPONSE B
(OFF→ON)
02 648
CN = 0.47 µF
CN = 0.33 µF
CN = 0.68µF
CN = 1.0 µF
TIME (ms)
I
LOAD
= 30 mA, CL = 2.2 µF
V
OUT
V
CONT
CN = 0.1 µF
CONTROL FUNCTION
ON/OFF RESPONSE WITH CONTROL
The turn-on time depends upon the value of the output
capacitor and the noise bypass capacitor. The turn-on time
will increase with the value of either capacitor. The graphs
below show the relationship between turn-on time and
load capacitance. If the value of these capacitors is reduced,
the load and line regulation will suffer and the noise voltage
will increase. If the value of these capacitors is increased,
the turn-on time will increase.
Page 11
March 1999 TOKO, Inc. Page 11
TK111xxS
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
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-23-5 is increased to 500 mW. For operation at
ambient temperatures over 25 °C, the power dissipation of
the SOT-23-5 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:
Tj = 0jA x PD + T
A
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/ P
D
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.
The range of usable currents can also be found from the
graph below.
Procedure:
1) Find P
D
2) PD1 is taken to be PD x (~ 0.8 - 0.9)
3) Plot PD1 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 PD against the point at which the
vertical line intersects the derating curve. This is taken
as the maximum power dissipation, DPD.
SOT-23-5 POWER DISSIPATION CURVE
0 50 100 150
TA (°C)
P
D
(mW)
0
0.6
1.0
0.2
0.4
0.8
MOUNTED AS
SHOWN
FREE AIR
P
D
D
PD
25 50 75 150
(mW)
TA (
C)
3
6
5
4
DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)
Page 12
Page 12 March 1999 TOKO, Inc.
TK111xxS
INPUT-OUTPUT CAPACITORS
Linear regulators require input and output capacitors in order to maintain regulator loop stability. The recommended
minimum value of the input capacitor is 0.1 µF. The output capacitor should be selected within the Equivalent Series
Resistance (ESR) range as shown in the graphs below for stable operation. When a ceramic capacitor is connected in
parallel with the output capacitor, a maximum of 1000 pF is recommended. This is because the ceramic capacitor's
electrical characteristics (capacitance and ESR) vary widely over temperature. If a large ceramic capacitor is used, a
resistor should be connected in series with it to bring it into the stable operating area shown in the graphs below. Minimum
resistance should be added to maintain load and line transient response.
Note: It is very important to check the selected manufacturers electrical characteristics (capacitance and ESR) over
temperature.
APPLICATION INFORMATION
100
10
1
0.1
0 .01
1 50 100
130
I
OUT
(mA)
ESR (Ω)
STABLE
OPERATION
AREA
100
10
1
0.1
0 .01
1 50 100
130
I
OUT
(mA)
ESR (Ω)
STABLE
OPERATION
AREA
100
10
1
0.1
0 .01
1 50 100
130
I
OUT
(mA)
ESR (Ω)
STABLE
OPERATION
AREA
100
10
1
0.1
0 .01
1 50 100
130
I
OUT
(mA)
ESR (Ω)
STABLE
OPERATION
AREA
CL = 1 µFC
L
= 2.2 µF
CL = 3.3 µF
CL = 10 µF
Note: It is not necessary to connect a ceramic capacitor in parallel
with an aluminum or tantalum output capacitor.
111xxS
C
L
ESR
TK111xxS
C
L
ESR
Page 13
March 1999 TOKO, Inc. Page 13
TK111xxS
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.
BOARD LAYOUT
Copper pattern should be as large as possible. Power dissipation is 500 mW for the SOT-23-5. A low ESR capacitor is
recommended. For low temperature operation, select a capacitor with a low ESR at the lowest operating temperature
to prevent oscillation, degradation of ripple rejection and increase in noise. The minimum recommended capacitance is
1.0 µF.
SOT-23-5 BOARD LAYOUT
APPLICATION INFORMATION (CONT.)
Note: ESR is measured at 10 kHz.
ESR
Capacitance
Aluminum
Capacitor
Tantalum
Capacitor
Ceramic
Capacitor
1.0 µF 2.4 Ω 2.3 Ω 0.140 Ω
2.2 µF 2.0 Ω 1.9 Ω 0.059 Ω
3.3 µF 4.6 Ω 1.0 Ω 0.049 Ω
10 µF 1.4 Ω 0.5 Ω 0.025 Ω
++
CONTROL
V
IN
V
OUT
NOISE BYPASS
GND
Page 14
Page 14 March 1999 TOKO, Inc.
TK111xxS
NOTES
Page 15
March 1999 TOKO, Inc. Page 15
TK111xxS
NOTES
Page 16
Page 16 March 1999 TOKO, Inc.
TK111xxS
0.95
0.95
0.950.95
e
M
0.1
2.9
1.6
1.1
0.15
0.4
2.8
1.90
2.4
e'
Recommended Mount Pad
1
23
45
1.0
0.7
(0.8)
0 - 0.1
(0.6)
(0.6)
1.4 max
e
e e
0.1
e1
0 - 15 max
Marking
± 0.3
+0.15
- 0.05
Dimensions are shown in millimeters
Tolerance: x.x = ± 0.2 mm (unless otherwise specified)
+0.15
-0.05
Marking Information
Product Code
TK111xxS W
Voltage Code
TK11120S 20
TK11121S 21
TK11122S 22
TK11123S 23
TK11124S 24
TK11125S 25
TK11127S 27
TK11128S 28
TK11129S 29
TK11130S 30
TK11131S 31
TK11132S 32
TK11133S 33
TK11134S 34
TK11135S 35
TK11136S 36
TK11137S 37
TK11138S 38
TK11139S 39
TK11140S 40
TK11141S 41
TK11142S 42
TK11143S 43
TK11144S 44
TK11145S 45
TK11146S 46
TK11147S 47
TK11148S 48
TK11149S 49
TK11150S 50
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-xxx-TK111S
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.
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
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