BU52273NUZ Datasheet, PDF (8/20 Pages) Rohm – Omnipolar Detection Hall IC

BU52273NUZ
Description of Operations
Micropower Operation (Small Current Consumption Using Intermittent Sensing)
IDD
Period
Startup Time
Standby Time
0
Figure 11
(Offset Cancellation)
The dual output omnipolar detection Hall IC uses
intermittent sensing save energy. At startup the Hall
elements, amplifier, 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.
Peak
Current
t
Period: Tp
Startup Time: Tp /4096x4 clk
Peak Current: 8mA
(Reference data, this is not thing guaranteeing.)
VDD
I
B_×
GND
Figure 12
＋
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 the Hall elements are connected as shown in Figure 12
and a magnetic field is applied perpendicular to the Hall
elements, a 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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TSZ02201-0M2M0F415140-1-2
24.May.2016 Rev.002