7/15

BU52069GWZ

TSZ02201-0M2M0F414040-1-2

© 2014 ROHM Co., Ltd. All rights reserved.

7.Nov.2014 Rev.001

www.rohm.com

TSZ22111

• 15 • 001

Description of Operations

Micropower Operation (Small Current Consumption Using Intermittent Sensing)

(Offset Cancellation)

The unipolar 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.

Reference Period: 50ms (MAX100ms)

Reference Startup Time:24µs

Standby Time

Startup Time

Period

t

Figure 12

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

13 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.

+

GND

-

I

Hall Voltage

Figure 13