BU52001GUL_11 Datasheet, PDF (23/32 Pages) Rohm – Omnipolar Detection Hall ICs Line up of supply voltage

BU52001GUL,BU52011HFV,BU52021HFV,BU52015GUL,BU52025G,BU52053NVX,
BU52054GWZ,BU52055GWZ,BU52056NVX,BU52061NVX,BD7411G
Technical Note
●Description of Operations
(Micropower Operation)
I_DD
Period
Startup time
Standby time
Fig.65
The bipolar detection Hall IC adopts an intermittent operation method
to save energy. At startup, the Hall elements, amp, comparator and
other detection circuits power ON and magnetic detection begins.
During standby, the detection circuits power OFF, thereby reducing
current consumption. The detection results are held while standby is
active, and then output.
Reference period: 50ms (MAX100ms)
Reference startup time: 48µs
t
※BD7411G don’t adopts an intermittent operation method.
(Offset Cancelation)
V_DD
I
B_×
GND
Fig.66
+
Hall Voltage
－
The Hall elements form an equivalent Wheatstone (resistor) bridge
circuit. Offset voltage may be generated by a differential in this bridge
resistance, or can arise from changes in resistance due to package or
bonding stress. A dynamic offset cancellation circuit is employed to
cancel this offset voltage.
When Hall elements are connected as shown in Fig. 66 and a
magnetic field is applied perpendicular to the Hall elements, voltage is
generated at the mid-point terminal of the bridge. This is known as Hall
voltage.
Dynamic cancellation switches the wiring (shown in the figure) to
redirect the current flow to a 90˚ angle from its original path, and
thereby cancels the Hall voltage.
The magnetic signal (only) is maintained in the sample/hold circuit
during the offset cancellation process and then released.
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23/31
2011.12 - Rev.G