ST LK112SM13TR, LK112SM14TR, LK112SM18TR, LK112SM19TR, LK112SM20TR User Manual

LK112Sxx

Low noise low drop voltage regulator with shutdown function

Features

■Output current up to 200 mA

■Low dropout voltage (500 mV max at IOUT = 200 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

■Wide range of output voltages

■Internal current and thermal limit

■VOUT tolerance ± 2% (at 25 °C)

■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

The LK112Sxx 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 used connected to the noise bypass pin to lower the output noise level to 30

SOT23-5L

µVrms. An internal PNP pass transistor is used to achieve a low dropout voltage.

The LK112Sxx has a very low quiescent current in ON MODE while in OFF MODE the Iq is reduced down to 100 nA max. The internal thermal shutdown circuitry limits the junction temperature to below 150 °C. The load current is internally monitored and the device will shutdown in the presence of a short circuit or overcurrent condition at the output.

Table 1.	Device summary
				Part numbers
LK112SXX13			LK112SXX24		LK112SXX36	LK112SXX45
LK112SXX14			LK112SXX26		LK112SXX37	LK112SXX46
LK112SXX18			LK112SXX28		LK112SXX38	LK112SXX47
LK112SXX19			LK112SXX29		LK112SXX39	LK112SXX48
LK112SXX20			LK112SXX31		LK112SXX41	LK112SXX49
LK112SXX21			LK112SXX33		LK112SXX42	LK112SXX50
LK112SXX22			LK112SXX34		LK112SXX43
LK112SXX23			LK112SXX35		LK112SXX44
July 2008				Rev 11		1/17
						www.st.com

Contents	LK112Sxx

Contents

1	Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 4
3	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
5	Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
6	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	12
7	Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
8	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	16

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LK112Sxx	Diagram

1 Diagram

Figure 1. Schematic diagram

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Pin configuration	LK112Sxx

2 Pin configuration

Figure 2. Pin connection (top view)

Table 2.	Pin description
Pin n°		Symbol	Note
1		SHDN	Shutdown Input: Disables the regulator when is connected to GND or to positive
			voltage less than 0.6 V
2		GND	Ground Pin: Internally connected to the die attach flag to decrease the total thermal
			resistance and increase the package ability to dissipate power.
3		Bypass	Bypass Pin: Bypass with 0.1 µF to improve the VREF thermal noise performances.
4		OUT	Output port
5		IN	Input port

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LK112Sxx			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	LK112Sxx

4 Electrical characteristics

Table 5. Electrical characteristics for LK112S (TJ = 25 °C, VIN=VOUT+1 V (1), IOUT = 0mA, VSHDN = 1.8 V, CI = 1 µF, CO = 2.2 µF, CBYPASS = 0.1 µF unless otherwise specified)

Symbol	Parameter		Test conditions	Min.	Typ.		Max.	Unit
Id	Quiescent current	ON MODE (except ISHDN)			175		250	µA
		OFF MODE, VI = 8V, VSHDN = 0V			0		0.1	µA
VO	Output voltage	IO = 30mA		(see table)
VO	Line regulation	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
VO	Load regulation	IO = 1 to 60mA			15		30	mV
		IO = 1 to 200mA			30		90	mV
		I	= 60 mA (2)		0.17		0.24	V
Vd	Dropout voltage	O
		I	= 200 mA (2)		0.35		0.5	V
		O
ISC	Short circuit current			200				mA
SVR	Supply voltage rejection	VI = VO+1.5V, CBYP = 0.1µF			55			dB
		CO = 10µF, f = 400Hz, IO = 30mA
eN	Output noise voltage	B= 10Hz to 80kHz, CBYP = 0.1µF			30			µVrms
		CO = 10µF, VI = VO+1.5V, IO = 60mA
ISHDN	Shutdown input current	VSHDN = 1.8V, Output ON			12		35	µA
VSHDN	Shutdown input logic	Output ON		1.8				V
		Output OFF					0.6
VO/TJ	Output voltage	IO = 10mA			0.09			mV/°C
	temperature coefficient

1.For version with output voltage less than 2V VIN=2.4V

2.Only for version with output voltage more than 2.1V

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