BD2270HFV View Datasheet(PDF) - ROHM Semiconductor
Part Name
Description
Manufacturer
BD2270HFV Datasheet PDF : 13 Pages
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BD2270HFV
Technical Note
●Functional Description
The BD2270HVF is a driver IC to use an N-channel MOSFET as a high side load switch. This IC incorporates the following
functions.
1. GATE drive
A voltage to drive the gate of N-channel MOSFET is generated by a built-in charge pump in the BD2270HFV. The built-in
charge pump in the BD2270HFV generates a voltage three times as high as the power supply voltage at the GATE
terminal. In addition, since this IC has a built-in capacitor for the charge pump, it needs no external parts.
The charge pump operates when the AEN is set to High. When the AEN is set to Low, the GATE terminal voltage is fixed
to the GND level.
2. Output discharge circuit
The output discharge circuit is enabled when the AEN is set to Low. When the discharge circuit is activated, the
200Ω(Typ.) MOSFET switch located between the DISC terminal and the GND terminal turns ON. Connecting between the
DISC terminal and the source side (load side) of the N-channel MOSFET makes it possible to immediately discharge
capacitive load.
3. Soft start function
When the AEN terminal input voltage reaches the High level, the built-in charge pump in the BD2270HFV charges the
gate of the N-channel MOSFET. The turn-on time of the N-channel MOSFET is determined by the GATE capacity. In
addition, connecting a capacitor to the GATE terminal makes it possible to slow the rise of turn-on time of the N-channel
MOSFET, thus achieving reduction of the inrush current to a large capacitive load.
4. Analog control input terminal
The AEN input of the BD2270HFV is connected to the built-in hysteresis comparator. Consequently, even analog signals
can control the BD2270HFV, thus facilitating the control of the switch ON-OFF sequence.
VCC
VIN_SWITCH
VAEN
VGATE
VOUT_SWITCH
放電回路
Discharge circuit
ON
OFF
ON
Fig. 34 Operation Timing
* To turn ON the power supply (VCC, VIN_SWITCH), set the AEN to Low.
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2009.04 - Rev.A
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