Rohm BU52040HFV Bipolar latch hall ic Datasheet

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
Supply voltage
(V)
BU52040HFV
1.65~3.30
Operation point Hysteresis
(mT)
(mT)
+/-3.0※
Period
(µs)
Supply current
(AVG)
(µA)
Output type
Package
500
200
CMOS
HVSOF5
6.0
※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
VDD
IOUT
Pd
Topr
Tstg
Limit
Unit
※1
-0.1~4.5
± 0.5
536※2
-40~+85
-40~+125
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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1/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Magnetic, Electrical Characteristics
BU52040HFV (Unless otherwise specified, VDD=1.80V, Ta=25°C)
Limit
Parameters
Symbol
Min
Typ
Max
Unit
Conditions
Power Supply Voltage
VDD
1.65
1.80
3.30
V
Operation point
Bop
1.0
3.0
5.0
mT
Release Point
Brp
-5.0
-3.0
-1.0
mT
Hysteresis
Bhys
-
6.0
-
mT
Tp
-
500
1200
µs
Output High Voltage
VOH
VDD - 0.2
-
-
V
B < Brp※3
IOUT =-0.5mA
Output Low Voltage
VOL
-
-
0.2
V
Bop < B※
IOUT =+0.5mA
Supply Current 1
IDD1(AVG)
-
200
300
µA
VDD =1.8V, Average
Supply Current
During Startup Time 1
IDD1(EN)
-
3.0
-
mA
VDD =1.8V,
During Startup Time Value
Supply Current
During Standby Time 1
IDD1(DIS)
-
2.0
-
µA
VDD =1.8V,
During Standby Time Value
Supply Current 2
IDD2(AVG)
-
300
450
µA
VDD=2.7V, Average
Supply Current
During Startup Time 2
IDD2(EN)
-
4.5
-
mA
VDD=2.7V,
During Startup Time Value
Supply Current
During Standby Time 2
IDD2(DIS)
-
3.5
-
µA
VDD=2.7V,
During Standby Time Value
Period
3
※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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2/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Figure of measurement circuit
Bop/Brp
Tp
VDD
VDD
VDD
200Ω
VDD
OUT
100μF
GND
Oscilloscope
OUT
GND
V
The period is monitored by Oscilloscope.
Bop and Brp are measured with applying the magnetic field
from the outside.
Fig.1
Fig.2
Bop,Brp measurement circuit
Tp measurement circuit
VOH
VDD
OUT
100μF
VDD
GND
Fig.3
V
IOUT=0.5mA
V
IOUT=0.5mA
VOH measurement circuit
VOL
VDD
VDD
OUT
100μF
GND
Fig.4
VOL measurement circuit
IDD
A
2200μF
VDD
VDD
OUT
GND
Fig.5
IDD measurement circuit
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3/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Reference Data
Bop
4.0
2.0
0.0
Brp
-2.0
-4.0
-6.0
-8.0
6.0
Ta = 25°C
700
Bop
4.0
PERIOD [ μs]
VDD=1.8V
MAGNETIC FLUX DENSITY [mT]
2.0
0.0
Brp
-2.0
1.8
2.2
2.6
3.0
3.4
SUPPLY VOLTAGE [V]
Fig.6 Bop,Brp–
Ambient temperature
Fig.7 Bop,Brp– Supply voltage
AVERAGE SUPPLY CURRENT [µA]
Ta = 25°C
600
500
400
300
200
1.4
1.8
2.2
2.6
3.0
3.4
3.8
350
Fig.8 TP– Ambient temperature
VDD=1.8V
300
250
200
150
100
400
350
Ta = 25°C
300
250
200
150
100
1.4
20 40 60 80 100
1.8
2.2
2.6
3.0
3.4
3.8
SUPPLY VOLTAGE [V]
AMBIENT TEMPERATURE [℃]
Fig.9 TP– Supply voltage
20 40 60 80 100
AMBIENT TEMPERATURE [℃]
400
-60 -40 -20 0
SUPPLY VOLT AGE [V]
-60 -40 -20 0
3.8
AMBIENT TEMPERATURE [℃]
700
400
200
1.4
800
500
300
-6.0
-8.0
20 40 60 80 100
VDD=1.8V
600
-4.0
AVERAGE SUPPLY CURRENT [µA]
MAGNETIC FLUX DENSITY [mT]
6.0
-60 -40 -20 0
PERIOD [μs]
800
8.0
8.0
Fig.11 IDD – Supply voltage
Fig.10 IDD– Ambient temperature
●Block Diagram
BU52040HFV
0.1 µF
VDD
4
Adjust the bypass capacitor
value as necessary, according
to voltage noise conditions, etc.
LATCH
SAMPLE
& HOLD
×
DYNAMIC
OFFSET
CANCELLATION
TIMING LOGIC
HALL
ELEMENT
5
The CMOS output terminals enable
direct connection to the PC, with no
external pull-up resistor required.
OUT
2
GND
Fig.12
PIN No.
PIN NAME
1
N.C.
2
GND
FUNCTION
5
4
4
5
3
3
2
1
Reverse
COMMENT
OPEN or Short to GND.
GROUND
3
N.C.
4
VDD
POWER SUPPLY
OPEN or Short to GND.
5
OUT
OUTPUT
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1
2
Surface
4/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●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
IDD
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.
VDD
I
B×
+
Hall Voltage
-
GND
Fig.14
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5/12
2010.01 - Rev.B
Technical Note
BU52040HFV
(Magnetic Field Detection Mechanism)
OUT [V]
High
Low
0
Brp
N-pole
B
Bop
S-pole
Magnetic flux density [mT]
Fig.15
The IC detects magnetic fields that running horizontal to the top layer of the package. When the magnetic pole switches
from N to S, the output changes from high to low; likewise, when the magnetic pole switches from S to N, the output
changes from low to high. The output condition is held unit the next switch in magnetic polarity is detected.
[Operation in Continuously Changing Magnetic Fields]
Direction of magnet movement
S
Magnet
S
N
N
S
S
N
N
S
S
N
N
Hall IC
S
Bop
N
Brp
Magnetic field
High
Hall IC output
Low
Fig.16
The IC can detect a continuous switch in magnetic field (from N to S and S to N) as depicted above.
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6/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Intermittent Operation at Power ON
VDD
Startup time
Standby time
Standby time
Startup time
Supply current
(Intermittent operation)
Indefinite
OUT
High
(N magnetic field present)
(B<Brp)
Indefinite interval
OUT
(S magnetic field present)
Low
(Bop<B)
Indefinite interval
OUT
(No magnetic field present)
(Brp<B< Bop)
Fig.17
The Hall Effect IC for wheel keys / trackballs adopts an intermittent operation method in detecting the magnetic field during
startup, as shown in Fig. 17. It outputs to the appropriate terminal based on the detection result and maintains the output
condition during the standby period. The time from power ON until the end of the initial startup period is an indefinite interval,
but it cannot exceed the maximum period, 1200μs. To accommodate the system design, the Hall IC output read should be
programmed within 1200μs of power ON, but after the time allowed for the period ambient temperature and supply voltage.
Additionally, if a magnetic flux density (B) of magnitude greater than Brp but less than Bop is applied at power ON, the output
from the IC remains undefined and will be either high or low until a flux density exceeding the Bop or Brp threshold is applied.
●Application Example
Wheel Key
Two Hall ICs can enable detection of rotation direction of a magnetic zero-contact wheel key.
Circular magnet
N
N
S
S
N
S
N
S
BU52040HFV: 2pcs
Mounting Position of Hall IC Inside Wheel Key
The angular separation of the two Hall ICs within the footprint of the wheel key depends on N/S division angle of the internal
magnet (Φ), and can be set to either Φ/4 or ¾Φ. Mounting the two ICs in this position causes the magnetic phase
difference between the ICs to equal ±1/4, and the direction of rotation can be detected by measuring the change in this
difference. An example of the magnetic field characteristics for this application is shown in the figure below.
1) Mounting angle of Hall IC = Φ/4
2) Mounting angle of Hall IC = ¾Φ
Φ/4
3/4 Φ
Hall IC B
Hall IC A
Hall IC A
θ
Center of magnet
θ
Hall IC B
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Counterclockwise
rotation
Center of magnet
Mounting Angle of Hall IC
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N/S division angle of circular magnet = Φ
Φ
N
S
N
S
S
N
S N
Clockwise
rotation
S
N
S
N S N S
N
Circular Magnet
7/12
2010.01 - Rev.B
Technical Note
BU52040HFV
Detection of Rotation Direction
1) Mounting angle = Φ/4
Counterclockwise Rotation
Clockwise Rotation
Magnetic field applied to IC A
Magnetic field applied to IC A
Magnetic field applied to IC B
Magnetic field applied to IC B
Bop
S
Bop
S
rotation angle
rotation angle
N
N
Brp
Hall IC A
Brp
Hall IC A
output
output
High
High
Low
Low
Hall IC B
Hall IC B
output
output
High
High
Low
Low
Clockwise turn: Output of IC B is low when
output of IC A becomes high
Counterclockwise turn: Output of IC B is high
when output of IC A becomes high
2) Mounting angle = ¾Φ
Clockwise Rotation
Counterclockwise Rotation
Magnetic field applied to IC A
Magnetic field applied to IC B
Magnetic field applied to IC A
Magnetic field applied to IC B
Bop
S
Bop
S
rotation angle
N
Brp
Hall IC A
output
rotation angle
N
Brp
Hall IC A
output
High
High
Low
Low
Hall IC B
Hall IC B
output
output High
High
Low
Low
Clockwise turn: Output of IC B is high when
Counterclockwise turn: Output of IC B is a low
output of IC A becomes high.
when output of IC A becomes high.
Because the IC measures changes in magnetic field every 1200 µS, the IC cannot detect changes in rotation at speeds
exceeding this period.
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8/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Magnet Selection
Horizontally Stacked Magnet
S
S
S
N
N
S
Vertically Stacked Magnet
N
N
S
S
N
Flux
Flux
Because the field loop in horizontally stacked magnets extends for a shorter distance than that of vertically stacked magnets,
the gap between the magnet and the hall IC must be decreased. Therefore, if horizontally-stacked magnets are used in the
application, the thickness of the magnet or the area of each section should be increased to allow for a larger gap between
the magnet and IC.
Because the IC is unable to detect rotation direction if using magnets that are smaller than the IC’s package size, ensure that
the physical size of each N/S division is larger than the IC’s package, and that the ICs are properly mounted with an angular
distance of either Φ/4 or ¾Φ from one another (where Φ = N/S division angle of circular magnet).
●IC Reference Position
Mounting angle of Hall IC
Magnet N/S division angle = Φ
Hall IC (x2)
Counterclockwise
rotation
N
S
N
S
S
N S
N
Clockwise
rotation
S
N
S
N SN S
N
Circular Magnet
●Position of the Hall Effect IC(Reference)
HVSOF5
0.6
0.8
0.2
(UNIT:mm)
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9/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Footprint dimensions (Optimize footprint dimensions to the board design and soldering condition)
HVSOF5
(UNIT:mm)
●Terminal Equivalent Circuit Diagram
Because they are configured for CMOS (inverter) output, the output pins require no external resistance and allow direct
connection to the PC. This, in turn, enables reduction of the current that would otherwise flow to the external resistor during
magnetic field detection, and supports overall low current (micropower) operation.
OUT
VDD
GND
Fig.18
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10/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Notes for use
1) Absolute maximum ratings
Exceeding the absolute maximum ratings for supply voltage, operating conditions, etc. may result in damage to or
destruction of the IC. Because the source (short mode or open mode) cannot be identified if the device is damaged in this
way, it is important to take physical safety measures such as fusing when implementing any special mode that operates in
excess of absolute rating limits.
2) GND voltage
Make sure that the GND terminal potential is maintained at the minimum in any operating state, and is always kept lower
than the potential of all other pins.
3) Thermal design
Use a thermal design that allows for sufficient margin in light of the power dissipation (Pd) in actual operating conditions.
4) Pin shorts and mounting errors
Use caution when positioning the IC for mounting on printed circuit boards. Mounting errors, such as improper positioning
or orientation, may damage or destroy the device. The IC may also be damaged or destroyed if output pins are shorted
together, or if shorts occur between the output pin and supply pin or GND.
5) Positioning components in proximity to the Hall IC and magnet
Positioning magnetic components in close proximity to the Hall IC or magnet may alter the magnetic field, and therefore
the magnetic detection operation. Thus, placing magnetic components near the Hall IC and magnet should be avoided in
the design if possible. However, where there is no alternative to employing such a design, be sure to thoroughly test and
evaluate performance with the magnetic component(s) in place to verify normal operation before implementing the design.
6) Operation in strong electromagnetic fields
Exercise extreme caution about using the device in the presence of a strong electromagnetic field, as such use may cause
the IC to malfunction.
7) Common impedance
Make sure that the power supply and GND wiring limits common impedance to the extent possible by, for example,
employing short, thick supply and ground lines. Also, take measures to minimize ripple such as using an inductor or
capacitor.
8) GND wiring pattern
When both a small-signal GND and high-current GND are provided, single-point grounding at the reference point of the set
PCB is recommended, in order to separate the small-signal and high-current patterns, and to ensure that voltage changes
due to the wiring resistance and high current do not cause any voltage fluctuation in the small-signal GND. In the same
way, care must also be taken to avoid wiring pattern fluctuations in the GND wiring pattern of external components.
9) Power source design
Since the IC performs intermittent operation, it has peak current when it’s ON. Please taking that into account and under
examine adequate evaluations when designing the power source.
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11/12
2010.01 - Rev.B
Technical Note
BU52040HFV
●Ordering part number
B
U
5
Part No
2
0
4
0
H
Part No
52040
F
V
Package
HFV : HVSOF5
-
T
R
Packaging and forming specification
TR: Embossed tape and reel
(HVSOF5)
HVSOF5
<Tape and Reel information>
4
Tape
Embossed carrier tape
(0.3)
Quantity
3000pcs
(0.91)
4
0.2MAX
(0.05)
5
(0.8)
5
(0.41)
1.6±0.05
1.0±0.05
Direction
of feed
TR
The direction is the 1pin of product is at the upper right when you hold
( reel on the left hand and you pull out the tape on the right hand
)
3 2 1
1 2 3
1pin
0.13±0.05
S
+0.03
0.02 –0.02
0.6MAX
1.2±0.05
(MAX 1.28 include BURR)
1.6±0.05
0.1
S
0.5
0.22±0.05
0.08
Direction of feed
M
(Unit : mm)
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Reel
12/12
∗ Order quantity needs to be multiple of the minimum quantity.
2010.01 - Rev.B
Notice
Notes
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The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
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use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
The Products specified in this document are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard
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The Products are not designed or manufactured to be used with any equipment, device or
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