TK112XX Datasheet, PDF (19/21 Pages) TOKO, Inc – VOLTAGE REGULATOR WITH ON/OFF SWITCH

TK112xx
APPLICATION INFORMATION
1.) Disabling the control pin
4.) Parallel connection for ON/OFF control
Connect control terminal to V_IN through a resistor (R).
Higher resistance values are good for reducing quiescent
current but this can cause the regulator to shut down at
lower input voltages. See Figure A.
V
IN
+
1 µF
6
5
4
R
V
O
+
10 µF
0 Ω ≤ R ≤ 300 kΩ
1
2
3
C = 10 nF
P
Figure A
2.) Using the control function
Turn on the regulator by setting the control pin voltage to
2.4 V or higher. Turn off the regulator by pulling the control
pin below 0.6 V. The regulator can also be controlled
directly from a TTL or CMOS device. See Figure B.
V
V
IN
O
6
5
4
+
1
µF
+
10 µF
V_IN
V_O
V_IN
11250
5V
Cont
+
GND
V_IN
V_O
11230
3V
+
0.1 µF
RS ^Cont
+
GND
V_IN
V_O
11220
2V
0.1 µF ⁺
Cont
+
GND
On/Off
To reduce IC power dissipation, connect a resistor, R_S, in
series with V_IN for the lower output voltage devices. This
will prevent thermal shutdown due to excessive power
dissipation.
5.) Constant current load
VIN
VO
+
112XX
R
+
ON/OFF
Cont
GND
+
1
2
3
R
C = 10 nF
P
Figure B
3.) Microprocessor/Logic Control
When there is a large ouput current, the quiescent current
also increases, and the difference becomes larger. When
using the ON/OFF control, the terminal voltage should be
set 2.4 V higher than the GND terminal of the IC. When the
ON/OFF control is not being used, connect it to V_IN.
VIN
VO
Microprocessor
112XX
Cont
+
GND
+
The Input and Control current in the off mode are less than
200 pA.
January, 1996 TOKO, Inc.
1-3-96
Page 19