BD6524HFV
Technical Note
●Functional description
1. Input / output
VIN pin and VOUT pin are connected to the drain and the source of N-MOS switch respectively. And the VIN pin is used
also as power source input to internal control circuit.
When EN input is set to High level and the switch is turned on, VIN pin and VOUT pin are connected by a 200mΩ switch.
In a normal condition, current flows from VIN to VOUT. If voltage of VOUT is higher than VIN, current flows from VOUT to
VIN, since the switch is bidirectional. There is not a parasitic diode between the drain and the source, it is possible to
prevent current from flowing reversely from VOUT pin to VIN pin when the switch is disabled.
2. Discharge circuit
When the switch between the VIN and the VOUT is OFF, the 200Ω(Typ.) discharge switch between VOUT and GND turns
on. By turning on this switch, electric charge at capacitive load is discharged.
3. Under voltage lockout (UVLO)
The UVLO circuit monitors the voltage of the VIN pin, when the EN input is active. UVLO circuit prevents the switch from
turning on until the VIN exceeds 2.2V(Typ.). If the VIN drops below 2.1V(Typ.) while the switch turns on, then UVLO shuts
off the switch.
While the switch between the VIN pin and VOUT pin is OFF owing to UVLO operations, the switch of the discharge circuit
turns on. However, when the voltage of VIN declines extremely, then the VOUT pin becomes Hi-Z.
VIN
VEN
VOUT
Discharg放e 電cir回cu路it ON
●Typical application circuit
2.1V(Typ.)
2.2V(Typ.)
OFF
ON OFF
Fig.31 Operation timing
ON OFF
VIN
VIN
0.1~1uF
EN
EN
VOUT
VOUT
GND
Fig.32 Typical application circuit
LOAD
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
7/9
2011.06 - Rev.C