Hall IC Series
Bipolar
Latch Hall IC
BU52040HFV
No.10045EBT05
●Description
BU52040 Hall Effect IC for wheel keys / trackballs is designed to detect a switch in magnetic field from N to S (or vice versa)
and maintain its detection result on the output until the next switch. Output is pulled low for S-pole fields and high for N-pole
fields. This IC is ideal for detecting the number of shaft rotations inside of a wheel key, trackball, or other similar applications.
Using two ICs can also enable detection of rotation direction.
●Features
1) Ideally suited for wheel keys or trackballs
2) Micropower operation (small current consumption via intermittent operation method)
3) Ultra-small outline package
4) Supports 1.8 V supply voltage
5) High ESD resistance: 8kV (HBM)
●Applications
Wheel keys (zero-contact selection dials), trackballs, and other interface applications.
●Product
Lineup
Product name
BU52040HFV
Supply voltage
(V)
1.65½3.30
Operation point Hysteresis
(mT)
(mT)
+/-3.0
※
6.0
Period
(µs)
500
Supply current
(AVG)
(µA)
200
Output type
CMOS
Package
HVSOF5
※Plus
is expressed on the S-pole; minus on the N-pole
●Absolute
Maximum Ratings
BU52040HFV (Ta = 25°C)
Parameters
Power Supply Voltage
Output Current
Power dissipation
Operating Temperature Range
Storage Temperature Range
Symbol
V
DD
I
OUT
Pd
T
opr
T
stg
Limit
-0.1½4.5
※
1
± 0.5
536
※
2
-40½+85
-40½+125
Unit
V
mA
mW
°C
°C
※1.
Not to exceed Pd
※2.
Reduced by 5.36mW for each increase in Ta of 1℃ over 25℃(mounted on 70mm×70 mm×1.6mm Glass-epoxy PCB)
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© 2010 ROHM Co., Ltd. All rights reserved.
1/12
2010.01 - Rev.B
BU52040HFV
●Magnetic,
Electrical Characteristics
BU52040HFV (Unless otherwise specified, V
DD
=1.80V, Ta=25°C)
Limit
Parameters
Symbol
Min
Typ
Power Supply Voltage
Operation point
Release Point
Hysteresis
Period
Output High Vol½age
Output Low Voltage
Supply Current 1
Supply Current
During Startup Time 1
Supply Current
During Standby Time 1
Supply Current 2
Supply Current
During Startup Time 2
Supply Current
During Standby Time 2
V
DD
B
op
B
rp
B
hys
T
p
V
OH
V
OL
I
DD1(AVG)
I
DD1(EN)
I
DD1(DIS)
I
DD2(AVG)
I
DD2(EN)
I
DD2(DIS)
1.65
1.0
-5.0
-
-
V
DD
- 0.2
-
-
-
-
-
-
-
1.80
3.0
-3.0
6.0
500
-
-
200
3.0
2.0
300
4.5
3.5
Technical Note
Max
3.30
5.0
-1.0
-
1200
-
0.2
300
-
-
450
-
-
Unit
V
mT
mT
mT
µs
V
V
µA
mA
µA
µA
mA
µA
Conditions
B < B
rp
※
3
I
OUT
=-0.5mA
3
B
op
< B
※
I
OUT
=+0.5mA
V
DD
=1.8V, Average
V
DD
=1.8V,
During Startup Time Value
V
DD
=1.8V,
During Standby Time Value
V
DD
=2.7V, Average
V
DD
=2.7V,
During Startup Time Value
V
DD
=2.7V,
During Standby Time Value
※3.
B = Magnetic flux density
1mT=10Gauss
Positive (“+”) polarity flux is defined as the magnetic flux from south pole which is direct toward to the branded face of the sensor.
After applying power supply, it takes one cycle of period (TP) to become definite output.
Radiation hardiness is not designed.
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© 2010 ROHM Co., Ltd. All rights reserved.
2/12
2010.01 - Rev.B
BU52040HFV
●Figure
of measurement circuit
B
op
/B
rp
T
p
200Ω
Technical Note
VDD
VDD
100μF
GND
OUT
V
VDD
VDD
Oscilloscope
GND
OUT
Bop and Brp are measured with applying the magnetic field
from the outside.
The period is monitored by Oscilloscope.
Fig.1
B
op
,B
rp
measurement circuit
Fig.2
T
p
measurement circuit
V
OH
VDD
VDD
100μF
GND
OUT
V
I
OUT
＝0.5mA
Fig.3
V
OH
measurement circuit
V
OL
VDD
VDD
100μF
GND
OUT
V
I
OUT
＝0.5mA
Fig.4
V
OL
measurement circuit
I
DD
A
VDD
OUT
GND
VDD
2200μF
Fig.5
I
DD
measurement circuit
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© 2010 ROHM Co., Ltd. All rights reserved.
3/12
2010.01 - Rev.B
BU52040HFV
●Reference
Data
8.0
MAGNETIC FLUX DENSITY [mT]
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
-8.0
-60 -40 -20 0
20 40 60 80 100
8.0
MAGNETIC FLUX DENSITY [mT]
800
Technical Note
V
DD
=1.8V
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
-8.0
1.4
Bop
Ta = 25°C
Bop
PERIOD [
μ
s]
700
600
500
400
300
200
V
DD
=1.8V
Brp
Brp
1.8
2.2
2.6
3.0
3.4
3.8
-60 -40 -20 0
20 40 60 80 100
AMBIENT TEMPERATURE [
℃
]
SUPPLY VOLTAGE
［V½
AMBIENT TEMPERATURE [
℃
]
Fig.6 Bop,Brp–
Ambient temperature
Fig.7 Bop,Brp– Supply voltage
Fig.8 T
P
– Ambient temperature
AVERAGE SUPPLY CURRENT [µA]
AVERAGE SUPPLY CURRENT [µA]
800
700
PERIOD [μs]
400
350
300
250
200
150
100
-60 -40 -20 0
20 40 60 80 100
AMBIENT TEMPERATURE [
℃
]
V
DD
=1.8V
400
350
300
250
200
150
100
1.4
1.8
2.2
2.6
3.0
3.4
3.8
SUPPLY VOLTAGE [V]
Ta = 25°C
Ta = 25°C
600
500
400
300
200
1.4
1.8
2.2
2.6
3.0
3.4
3.8
SUPPLY VOLT AGE [V]
Fig.9 T
P
– Supply voltage
●Block
Diagram
BU52040HFV
ＶDD
Fig.10 I
DD
– Ambient temperature
Fig.11 I
DD
– Supply voltage
0.1 µF
4
TIMING LOGIC
DYNAMIC
OFFSET
CANCELLATION
HALL
ELEMENT
Adjust the bypass capacitor
value as necessary, according
to voltage noise conditions, etc.
SAMPLE
& HOLD
×
5
OUT
The CMOS output terminals enable
direct connection to the PC, with no
external pull-up resistor required.
LATCH
2
GND
Fig.12
PIN No.
1
2
3
4
5
PIN NAME
N.C.
GND
N.C.
VDD
OUT
POWER SUPPLY
OUTPUT
GROUND
OPEN or Short to GND.
FUNCTION
COMMENT
OPEN or Short to GND.
5
4
4
5
1
2
3
3
Surface
2
1
Reverse
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© 2010 ROHM Co., Ltd. All rights reserved.
4/12
2010.01 - Rev.B
BU52040HFV
Technical Note
●Description
of Operations
(Micro-power Operation)
The Hall Effect IC for wheel keys / trackballs 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: 500 µs (MAX. 1200 µs)
Reference startup time: 24 µs
I
DD
Period
Startup time
Standby
t
Fig.13
(Offset Cancellation)
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. 14 and a magnetic field is applied perpendicularly to the Hall
elements, voltage is generated at the mid-point terminal of the bridge. This is known as the 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.
V
DD
I
B
×
＋
Hall Voltage
－
GND
Fig.14
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© 2010 ROHM Co., Ltd. All rights reserved.
5/12
2010.01 - Rev.B
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