TK717xxS
APPLICATION INFORMATION (CONT.)
As shown in the figure below, several components are required to discharge the charge in the output side capacitor in a
typicalregulator.
V
V
OUT
IN
DISCHARGE CIRCUIT
On/Off Control
TK717xxS (TOKO REGULATOR)
Doesn’t need discharge circuit
BecausetheexternalelectricaldischargecircuitisunnecessarywiththeTK717xxS, theapplicationbecomesverysimple.
Turning the regulator off automatically discharges the charge of the output side capacitor.
DISCHARGE CURRENT IN OFF MODE
V
OUT
V
IN
On/Off CONTROL
The TK112xxB is a normal regulator.
The TK717xx is built with the automatic discharge circuit during off time.
The TK716xxS, AS is built with the output disconnect circuit.
As shown here:
on
off response: CL = 2.2 µF
C
= 1000 pF I Load = 0mA
N
CONTROL
TK716xxS, AS
TK112xxB
V
OUT
TK717xx
0
200
400
TIME(µS)
600
Page12
October 2001 TOKO, Inc.
TOKO [ TOKO, INC ]
