ST LK112M15TR, LK112M18TR, LK112M19TR, LK112M20TR, LK112M22TR User Manual

LK112xx

Low noise low drop voltage regulator with shutdown function

Features

■Output current up to 150 mA

■Low dropout voltage (350 mV at IOUT = 50 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:	SOT23-5L
	– typ. 30 µV at IOUT = 60 mA and 10 Hz < f <
	80 kHz
	■ Wide range of output voltages
	■ 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

The LK112xx 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 µVrms. An internal PNP pass transistor is used to achieve a low dropout voltage. The LK112xx 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
LK112XX15			LK112XX25		LK112XX50	LK112XX60
LK112XX18			LK112XX33		LK112XX55	LK112XX80
February 2011			Doc ID 7362 Rev 16			1/17
						www.st.com

Contents	LK112xx

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

2/17	Doc ID 7362 Rev 16

LK112xx	Diagram

1 Diagram

Figure 1. Schematic diagram

Doc ID 7362 Rev 16

3/17

Pin configuration	LK112xx

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

4/17	Doc ID 7362 Rev 16

LK112xx			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

Doc ID 7362 Rev 16

5/17

Electrical characteristics	LK112xx

4 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.	Electrical characteristics for LK112
Symbol	Parameter	Test conditions	Min.	Typ.		Max.	Unit
Iq	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 150mA		25		90	mV
		I = 60 mA (1)		0.17		0.24	V
Vd	Dropout voltage	O
		I = 150 mA (1)		0.29		0.35	V
		O
IO	Output current limit		150				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. Only for version with output voltage more than 2.1 V
Note:	For version with output voltage less than 2 V, VIN = 2.4 V.

6/17	Doc ID 7362 Rev 16