BU6909AGFT Datasheet, PDF (14/21 Pages) Rohm – Built in HALL element

BU6909AGFT
Datasheet
Safety measure
1) Reverse connection protection diode
Reverse connection of power results in IC destruction as shown in Figure 27. When reverse connection is possible,
reverse connection protection diode must be added between power supply and VCC.
In normal energization
Reverse power connection
After reverse connection destruction
prevention
VCC
VCC
VCC
Circuit
block
Each
Pin
Circuit
block
Each
Pin
Circuit
block
Each
Pin
GND
GND
GND
Internal circuit impedance high
→ amperage small
Large current flows
→ Thermal destruction
No destruction
Figure 27. Flow of current when power is connected reversely
2) Protection against VCC voltage rise by back electromotive force
Back electromotive force (Back EMF) generates regenerative current to power supply. However, when reverse
connection protection diode is connected, VCC voltage rises because the diode prevents current flow to power supply.
ON
ON
ON _{Phase switching}
ON
Figure 28. VCC voltage rise by back electromotive force
When the absolute maximum rated voltage may be exceeded due to voltage rise by back electromotive force, place a
(A) Capacitor or (B) Zener diode between VCC and GND. If necessary, add both (C). (D) Capacitor and resistor can
also be used to have better ESD surge protection.
(A) Capacitor
(B) Zener diode
ON
ON
ON
ON
(C) Capacitor and Zener diode
ON
ON
(D) Capacitor and resistor
ON
ON
Figure 29. Protection against VCC voltage rise
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TSZ22111・15・001
14/18
TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002