
October 1999 TOKO, Inc.
Page 1
TK112xxB
FEATURES
I
 High Voltage Precision at 
±
 2.0%
I
 Active High On/Off Control
I
 Very Low Dropout Voltage 80 mV at 30 mA
I
 Very Low Noise
I
 Very Small SOT-23L or SOT-89 Surface Mount
Packages
I
 Internal Thermal Shutdown
I
 Short Circuit Protection
APPLICATIONS
I
 Battery Powered Systems
I
 Cellular Telephones
I
 Pagers
I
 Personal Communications Equipment
I
 Portable Instrumentation
I
 Portable Consumer Equipment
I
 Radio Control Systems
I
 Toys
I
 Low Voltage Systems
BLOCK DIAGRAM
TK112xxB
GND
CONTROL
VOUT
VIN
NOISE BYPASS
GND
VOUT
GND
NOISE BYPASS
GND
CONTROL
VIN
DESCRIPTION
The TK112xxB 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 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 
μ
Vrms.
An internal PNP pass transistor is used to achieve a low
dropout voltage of 80 mV (typ.) at 30 mA load current. The
TK112xxB  has a very low quiescent current of 170 
μ
A at
no load and 1 mA with a 30 mA load.  The standby current
is typically 100 nA. 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 TK112xxB is available in either  a 6-pin SOT-23L or a
5-pin SOT-89 surface mount package.
ORDERING INFORMATION
TAPE/REEL CODE
L: Tape Left (SOT-23L)
B: Tape Left (SOT-89)
TEMP. CODE:
C: -30 to +80 C
I: -40 to +85 C
Tape/Reel Code
TK112      B
Voltage Code
Package Code
PACKAGE CODE:
M: SOT-23L
U: SOT-89
1.3 V to 1.9 V available
1.3 V to 2.4 V available
VOLTAGE CODE
13 = 1.3 V 
14 = 1.4 V 
15 = 1.5 V 
16 = 1.6 V 
17 = 1.7 V 
18 = 1.8 V 
19 = 1.9 V 
20 = 2.0 V 
21 = 2.1 V 
22 = 2.2 V 
23 = 2.3 V 
24 = 2.4 V 
25 = 2.5 V 
26 = 2.6 V 
27 = 2.7 V 
28 = 2.8 V 
29 = 2.9 V 
30 = 3.0 V 
31 = 3.1 V 
32 = 3.2 V 
33 = 3.3 V
34 = 3.4 V
35 = 3.5 V
36 = 3.6 V
37 = 3.7 V
38 = 3.8 V
39 = 3.9 V
40 = 4.0 V
41 = 4.1 V
42 = 4.2 V
43 = 4.3 V
44 = 4.4 V
45 = 4.5 V
46 = 4.6 V
47 = 4.7 V
48 = 4.8 V
49 = 4.9 V
50 = 5.0 V
55 = 5.5 V
80 = 8.0 V
Temp. Code
20P
NOISE
VIN
VOUT
PTHERMAL
BANDGAP
CONTROL
GND
SOT-23L
SOT-89
VOLTAGE REGULATOR WITH ON/OFF SWITCH