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

Low noise low drop voltage regulator with shutdown function

Features

■ Output current up to 150 mA

■ Low dropout voltage (350 mV at I

■ Very low quiescent current:

– 0.1 µA in OFF mode and max. 250 µA in

ON mode at I

■ Low output noise:

– typ. 30 µV at I

= 0 mA

OUT

= 60 mA and 10 Hz < f <

OUT

80 kHz

■ Wide range of output voltages

■ Internal current and thermal limit

■ Operative input voltage from:

–V

+ 0.5 to 14 V (for V

OUT

2.5 V to 14 V (for V

OUT

< 2 V)

OUT

> 2 V) or from

OUT

LK112xx

= 50 mA)

SOT23-5L

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 I
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

is reduced down to 100 nA max. The

q

Part numbers

LK112XX15 LK112XX25 LK112XX50 LK112XX60

LK112XX18 LK112XX33 LK112XX55 LK112XX80

February 2011 Doc ID 7362 Rev 16 1/17

www.st.com

17

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

2GND

3 Bypass Bypass pin: bypass with 0.1 µF to improve the V

4 OUT Output port

5 IN Input port

Shutdown input: disables the regulator when 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.

thermal noise performances.

REF

4/17 Doc ID 7362 Rev 16

LK112xx Maximum ratings

3 Maximum ratings

Table 3. Absolute maximum ratings

Symbol Parameter Value Unit

V

T

V

I

SHDN

I

O

STG

T

OP

DC input voltage 16 V

DC input voltage 16 V

Output current Internally limited

Storage temperature range -55 to 150 °C

Operating junction temperature range -40 to 125 °C

Table 4. Thermal data

Symbol Parameter SOT23-5L Unit

R

thJC

R

thJA

Thermal resistance junction-case 81 °C/W

Thermal resistance junction-ambient 255 °C/W

Doc ID 7362 Rev 16 5/17

Electrical characteristics LK112xx

4 Electrical characteristics

TJ = 25 °C, V

IN

= V

OUT

+ 1 V, I

OUT

= 0 mA, V

= 1.8 V, CI = 1 µF, CO = 2.2 µF, C

SHDN

BYPASS

0.1 µF unless otherwise specified.

Table 5. Electrical characteristics for LK112

Symbol Parameter Test conditions Min. Typ. Max. Unit

I

q

V

O

ΔV

O

ΔV

O

V

d

I

O

SVR Supply voltage rejection

eN Output noise voltage

I

SHDN

V

SHDN

ΔV

O/TJ

Quiescent current

ON MODE (except I

OFF MODE, V

= 8V, V

I

)175250µA

SHDN

= 0V 0 0.1 µA

SHDN

Output voltage IO = 30mA (see table)

V

= VO+1V to VO+6V, VO ≤ 5.6V 0.7 20 mV

Line regulation

I

= VO+1V to VO+6V, VO > 5.6V 0.8 40 mV

V

I

IO = 1 to 60mA 15 30 mV

Load regulation

= 1 to 150mA 25 90 mV

I

O

(1)

(1)

0.17 0.24 V

0.29 0.35 V

Dropout voltage

IO = 60 mA

= 150 mA

I

O

Output current limit 150 mA

V

Shutdown input current V

= VO+1.5V, C

I

CO = 10µF, f = 400Hz, IO = 30mA

B= 10Hz to 80kHz, C

= 10µF, VI = VO+1.5V, IO = 60mA

C

O

= 1.8V, Output ON 12 35 µA

SHDN

BYP

= 0.1µF

= 0.1µF

BYP

55 dB

30 µVrms

Output ON 1.8

Shutdown input logic

Output OFF 0.6

Output voltage
temperature coefficient

I

= 10mA 0.09 mV/°C

O

=

V

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

Note: For version with output voltage less than 2 V, V

6/17 Doc ID 7362 Rev 16

= 2.4 V.

IN