FDC6324L FET switch load switch 20V 1A SSOT-6 TSOP-6
VDROP=0.2V @ VIN=12V, I L =1A, VON/OFF=1.5 to 8V VDROP=0.3V @ VIN=5V, I L =1A, VON/OFF=1.5 to 8V. High density cell design for extremely low on-resistance. VON/OFF Zener protection for ESD ruggedness. >6KV Human Body Model. SuperSOTTM-6 package design using copper lead frame for superior thermal and electrical capabilities.
This device is particularly suited for computer peripheral switching applications where 20V input and 1A output current capability are needed. This load switch integrates a small N-Channel Power MOSFET (Q1) which drives a large P-Channel Power MOSFET (Q2) in one tiny SuperSOTTM-6 package.
A load switch is usually configured for high side switching so that the load can be isolated from the active power source. A P-Channel Power MOSFET, because it does not require its drive voltage above the input voltage, is usually more cost effective than using an N-Channel device in this particular application. A large P-Channel Power MOSFET minimizes voltage drop. By using a small N-Channel device the driving stage is simplified.
R1 Typical 10k - 1MW
R2 Typical 0 - 10kW (optional)
C1 Typical 1000pF (optional)
R1 is needed to turn off Q2.
R2 can be used to soft start the switch in the case the output capacitance Co is small.
R2 £ should be at least 10 times smaller than R1 to guarantee Q1 turns on.
By using R1 and R2 a certain amount of current is lost from the input. This bias current loss is given by
IBIAS _LOSS = Vin when the switch is ON. IBIAS_LOSS can be minimized by large R1.
R 1 +R2
R2 and CRSS of Q2 make ramp for slow turn on. If excessive overshoot current occurs due to fast turn on,
additional capacitance C1 can be added externally to slow down the turn on.