LK112
Low noise and low drop voltage regulator with shutdown function
Datasheet - production data
• Internal current and thermal limit
• Operative input voltage from:
– VOUT + 0.5 to 14 V (for VOUT > 2 V) or from
2.5 V to 14 V (for VOUT < 2 V)
Description
SOT23-5L
Features
• Output current up to 150 mA
• Low-dropout voltage (350 mV at IOUT = 150
mA)
• Very low quiescent current:
– 0.1 µA in OFF mode and max. 250 µA in
ON mode at IOUT = 0 mA
• Low output noise:
– typ. 30 µV at IOUT = 60 mA and 10 Hz < f <
80 kHz
The LK112 is a low-dropout linear regulator with a
built-in electronic switch. The internal switch can
be controlled by TTL or CMOS logic levels. The
device is 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 reduce the
output noise level to 30 µVrms. An internal PNP
pass transistor is used to achieve a low-dropout
voltage. The LK112 has a very low quiescent
current in on mode while in off mode Iq is reduced
below 100 nA max. The internal thermal
shutdown circuitry limits the junction temperature
below 150 °C. Load current is internally monitored
and the device shuts down in the presence of a
short-circuit or overcurrent condition on the
output.
• Wide range of output voltages
Table 1. Device summary
Order codes
Output voltages
LK112M15TR
1.5V
LK112M18TR
1.8V
LK112M25TR
2.5V
LK112M33TR
3.3V
LK112M50TR
5.0V
LK112M55TR
5.5V
LK112M60TR
6.0V
LK112M80TR
8.0V
April 2014
This is information on a product in full production.
DocID7362 Rev 17
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www.st.com
Contents
LK112
Contents
1
Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5
Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7
Packaging mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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Diagram
Diagram
Figure 1. Schematic diagram
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Pin configuration
2
LK112
Pin configuration
Figure 2. Pin connection (top view)
Table 2. Pin description
Pin n°
Symbol
1
SHDN
2
GND
3
Bypass
4
OUT
5
IN
4/18
Note
Shutdown input disables the regulator when it is connected to GND or to positive
voltage less than 0.6 V
Ground pin internally connected to the die attach flag to decrease the total thermal
resistance and increase the package ability to dissipate power
Bypass pin with 0.1 µF to improve the noise performance
Output port
Input port
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LK112
Maximum ratings
3
Maximum ratings
Table 3. Absolute maximum ratings
Symbol
Parameter
Value
Unit
VI
DC input voltage
16
V
VSHDN
DC input voltage
16
V
IO
Output current
Internally limited
TSTG
Storage temperature range
-55 to 150
°C
TOP
Operating junction temperature range
-40 to 125
°C
Table 4. Thermal data
Symbol
Parameter
SOT23-5L
Unit
RthJC
Thermal resistance junction-case
81
°C/W
RthJA
Thermal resistance junction-ambient
255
°C/W
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Electrical characteristics
4
LK112
Electrical characteristics
TJ = 25 °C, VIN = VOUT + 1 V, IOUT = 0 mA, VSHDN = 1.8 V, CI = 1 µF, CO = 2.2 µF,
CBYPASS = 0.1 µF unless otherwise specified.
Table 5. LK112 electrical characteristics
Symbol
Parameter
Iq
Quiescent current
VO
Output voltage
ΔVO
Line regulation
ΔVO
Load regulation
Test conditions
Min.
On mode (except ISHDN)
Off mode, VI = 8V, VSHDN = 0V
Vd
Dropout voltage
IO
Output current limit
IO = 30mA
Typ.
Max.
Unit
175
250
µA
0
0.1
µA
+2
%
-2
VI = VO+1V to VO+6V, VO ≤ 5.6V
0.7
20
mV
VI = VO+1V to VO+6V, VO > 5.6V
0.8
40
mV
IO = 1 to 60mA
15
30
mV
IO = 1 to 150mA
25
90
mV
0.17
0.24
V
0.29
0.35
V
IO = 60mA
(1)
IO = 150mA
(1)
150
mA
Supply voltage rejection
VI = VO+1.5V, CBYP = 0.1µF
CO = 10µF, f = 400Hz, IO = 30mA
55
dB
Output noise voltage
B= 10Hz to 80kHz, CBYP = 0.1µF
CO = 10µF, VI = VO+1.5V, IO = 60mA
30
µVrms
ISHDN
Shutdown input current
VSHDN = 1.8V, output on
12
VSHDN
Shutdown input logic
ΔVO/TJ
Output voltage
temperature coefficient
SVR
eN
Output on
6/18
µA
1.8
V
Output off
IO = 10mA
1. For versions with output voltage more than 2.1 V only.
Note:
35
For version with output voltage less than 2 V, VIN = 2.4 V.
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0.6
0.09
mV/°C
LK112
5
Typical characteristics
Typical characteristics
Unless otherwise specified, TJ = 25 °C, CI = 1 µF, CO = 2.2 µF, CBYP = 100 nF
Figure 3. Output voltage vs. temperature (VO= 2.5V)
Figure 4. Output voltage vs. temperature
(VO= 3.8V)
Figure 5. Line regulation vs. temperature
Figure 6. Load regulation vs. temperature
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Typical characteristics
LK112
Figure 7. Dropout voltage vs. temperature
Figure 8. Short-circuit current vs. dropout
voltage
Figure 9. Output voltage vs. input voltage
Figure 10. Shutdown voltage vs. temperature
2.5 V
2V
30 mA
Figure 11. Shutdown current vs. shutdown
voltage
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Figure 12. Supply voltage rejection vs.
temperature (VO= 2.5V)
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LK112
Typical characteristics
Figure 13. Supply voltage rejection vs. output
current
Figure 14. Supply voltage rejection vs.
frequency
Figure 15. Supply voltage rejection vs.
temperature (VO= 3.8V)
Figure 16. Quiescent current vs. temperature
Figure 17. Quiescent current vs. input voltage
Figure 18. Quiescent current vs. shutdown
voltage
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Typical characteristics
LK112
Figure 19. Quiescent current vs. output current Figure 20. Reverse current vs. reverse voltage
Figure 21. Stability
Figure 22. Noise spectrum
Figure 23. Start-up transient (CBYP = 10 nF)
Figure 24. Start-up transient (CBYP = 100 nF)
VI=3.5V, VO=2.5V, VSHDN= 0 to 1.8V, RL=2.5kΩ, CI=1µF,
CO=4.7µF, CBYP=10nF
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VI=3.5V, VO=2.5V, VSHDN= 0 to 1.8V, RL=68Ω, CI=1µF,
CO=4.7µF, CBYP=100nF
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LK112
Typical characteristics
Figure 25. Line transient (Co = 100 µF)
VI=3.5 to 4.5V, VO=2.5V, VSHDN= 1.8V, IO=30mA, no CI,
CO=100µF, CBYP=10nF, ts=tf=2µs
Figure 27. Line transient (Co = 1 µF)
VI=3.5 to 4.5V, VO=2.5V, VSHDN= 1.8V, IO=30mA, no CI,
CO=1µF, CBYP=1nF, ts=tf=2µs
Figure 26. Line transient (Co = 10 µF)
VI=3.5 to 4.5V, VO=2.5V, VSHDN= 1.8V, IO=30mA, no CI,
CO=10µF, CBYP=10nF, ts=tf=2µs
Figure 28. Load transient (Co = 2.2 µF,
CBYP = 10 nF)
VI=3.5V, VO=2.5V, VSHDN= 1.8V, IO=50 to 100mA, CI=1µF,
CO=2.2µF, CBYP=10nF, ts=tf=250ns
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Typical characteristics
LK112
Figure 29. Load transient (Co = 10 µF,
CBYP = 100 nF)
VI=3.5V, VO=2.5V, VSHDN= 1.8V, IO=50 to 100mA, CI=1µF,
CO=10µF, CBYP=100nF, ts=tf=250ns
12/18
Figure 30. Load transient (Vo = 3.8 V)
VI=4.8V, VO=3.8V, VSHDN= 1.8V, IO=50 to 100mA, CI=1µF,
CO=2.2µF, CBYP=10nF, ts=tf=250ns
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LK112
6
Package mechanical data
Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.
Figure 31.SOT23-5L mechanical drawings
BN
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Package mechanical data
LK112
Table 6. SOT23-5L mechanical data
mm
Dim.
Min.
Typ.
Max.
A
0.90
1.45
A1
0
0.15
A2
0.90
1.30
b
0.30
0.50
c
2.09
0.20
D
2.95
E
1.60
e
0.95
H
2.80
L
0.30
0.60
θ
0
8
Figure 32. SOT23-5L recommended footprint (dimensions in mm)
BN
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Packaging mechanical data
Packaging mechanical data
Figure 33.Tape and reel SOT23-5L mechanical drawings
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Packaging mechanical data
LK112
Figure 34. Tape and reel SOT23-5L mechanical data
mm
Dim.
Min.
Typ.
A
180
C
12.8
D
20.2
N
60
13.0
T
16/18
Max.
13.2
14.4
Ao
3.13
3.23
3.33
Bo
3.07
3.17
3.27
Ko
1.27
1.37
1.47
Po
3.9
4.0
4.1
P
3.9
4.0
4.1
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LK112
8
Revision history
Revision history
Table 7. Document revision history
Date
Revision
31-Jan-2005
8
Change maturity code.
13-Jun-2006
9
Order codes updated and new template.
17-Oct-2006
10
The TOP value on table 2 has been updated.
18-Jul-2007
11
Add Table 1 in cover page.
21-Sep-2007
12
Features updated.
11-Dec-2007
13
Modified: Table 1.
12-Feb-2008
14
Modified: Table 1.
10-Jul-2008
15
Modified: Table 1 and Table 1 on page 1.
28-Feb-2011
16
Modified: Table 1.
17
Changed the part number LK112xx to LK112.
Updated the Title in cover page and Table 1: Device summary.
Updated the features and description in cover page, Table 2: Pin
description, Figure 3: Output voltage vs. temperature (VO= 2.5V),
Figure 4: Output voltage vs. temperature (VO= 3.8V), Section 5:
Typical characteristics, Section 6: Package mechanical data.
Added Section 7: Packaging mechanical data.
Minor text changes.
24-Apr-2014
Changes
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LK112
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