TCK104G Datasheet, PDF (6/12 Pages) Toshiba Semiconductor – Load Switch IC with Current Limit function

Application Note
1. Application circuit example (top view)
TCK104G,TCK105G
The figure below shows the recommended configuration for TCK104G and TCK105G
CONTROL
GND
VIN
C_IN
V_OUT
C_L
LOAD
R_L
Control
voltage
HIGH
LOW
OPEN
IC
Operation
ON
OFF
OFF
1) Input capacitor
An input capacitor(C_IN) is not necessary for the guaranteed operation of TCK104G and TCK105G. However, it is
recommended to use input capacitors to reduce voltage drop due to sharp changes in output current and also for
improved stability of the power supply. When used, place C_IN as close to V_IN pin to improve stability of the power
supply. Also, due to the C_IN selected, V_IN < V_OUT may occur, causing a reverse current to flow through the body
diode of the pass-through p-ch MOSFET of the load switch IC. In this case, a higher value for C_IN as compared to
C_L is recommended.
2) Output capacitor
An output capacitor (C_OUT) is not necessary for the guaranteed operation of TCK104G and TCK105G. However,
there is a possibility of overshoot or undershoot caused by output load transient response, board layout and
parasitic components of load switch IC. In this case, an output capacitor with C_OUT more than 0.1μF us
recommended.
3) Control pin
A control pins for TCK104G and TCK105G are both Active High, which controls both the pass-through p-ch
MOSFET and the discharge n-ch MOSFET, operated by the control voltage and Schmitt trigger. When the control
voltage level is High, p-ch MOSFET is ON state and n-ch MOSFET is OFF state. When control voltage level is
Low, and the state of the MOSFETs is reversed. Also, pull down resistance equivalent to a few MΩis connected
between CONTROL and GND, thus the load switch IC is in OFF state even when CONTROL pin is OPEN. In
addition, CONTROL pin has a tolerant function such that it can be used even if the control voltage is higher than
the input voltage.
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2014-03-01