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[AK8777B]
AK8777B
H a l l l l
E f f f f e e c t t
I
I
C f f o r r
P u l l s s e e E n c c o d e r r s s
Overview
The AK8777B is a Hall effect latch which detects both “vertical” and “horizontal”(perpendicular and parallel to the marking side of the package) magnetic field at the same time. The output OUTA and OUTB are switched according to the vertical and horizontal magnetic fields applied to the device. The AK8777B is for use in the incremental pulse encoders or rotational detection systems.
Features
o 4.0 to 24V supply voltage operation o
Sensitivity (Vertical, Horizontal) : ±1.7mT(Typ.) o Two outputs : OUTA (detects vertical magnetic field), OUTB (detects horizontal magnetic field) o Small package: SOP-6pin o Halogen free
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[AK8777B]
VDD
VSS
REGULATOR
VREG
Block Diagram
BIAS
HE_DRIVE
CHOP_AMP COMP
OSC
TIMING
LOGIC
OUTA
OUTB
HALL SENSORS
Figure 1. Block diagram
Circuit Configuration
Block
REGULATOR
HALL SENSORS
CHOPPER_SW
CHOP_AMP
COMP
BIAS
HE_DRIVE
OSC
TIMING LOGIC
LATCH & LOGIC
Table 1. Circuit configuration
Function
Generate internal operating voltage.
Two Hall elements fabricated by CMOS process.
Perform chopping in order to cancel the offset of Hall sensor.
Amplifies two Hall sensor output voltage with summation and subtraction circuit.
Hysteresis comparator.
Generates bias current to internal circuits.
Generates bias current for Hall sensors.
Generates operating clock.
Generates timing signal for internal circuits.
Logical circuits and open drain driver.
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Pin/Function
Table 2. Description of pin name and function
Pin No. Pin name I/O
1 VDD
2
3
4
5
6
TAB
OUTA
OUTB
TAB
VSS
O
O
Note) TAB pins should be connected to VSS.
Function
Power supply pin
(TAB pin)
Output A pin. Relating to the vertical magnetic field.
Output B pin. Relating to the horizontal magnetic field.
(TAB pin)
Ground pin
Absolute Maximum Ratings
Note
Open drain
Open drain
Parameter
Supply voltage
Output voltage
Symbol
V
V
T able 3. Absolute maximum ratings
DD
OUT
Min.
−
0.3
−
0.3
Max.
+32
+32
Unit
V
V
Output current
Storage temperature
I
T
OUT
STG
−
55
20
+150 mA
°
C
Note) Stress beyond these listed values may cause permanent damage to the device.
Recommended Operating Conditions
Parameter
Supply voltage
Output current
Operating temperature
Table 4. Recommended operating conditions
Symbol
I
V
DD
SINK
Ta
Min.
4.0
−
40
Typ.
12.0
Max.
24.0
15
+125
Note
VSS=0V
OUTA,OUTB pin
VSS=0V
OUTA,OUTB pin
Unit
V mA
°
C
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Electrical Characteristics
Table 5. Electrical characteristics at V
DD
=4.0 to 24.0V, Ta=
−
40 to +125
°
C
Parameter
Current consumption
Output saturation voltage
Output leak current
Output refresh period
Symbol Min.
I
DD
1.4
I
V
SAT
LEAK
T
P
12.0
Typ.
3.0
16.7
Max. Unit
5.6 mA
0.4
10
30.5
Note
V
OUTA,OUTB pin,
I
SINK
= 15mA
µ
A OUTA, OUTB =V
µ s
DD
Magnetic Characteristics
Hysteresis
Table 6. Magnetic characteristics at V
DD
=4.0 to 24.0V, Ta=
−
40 to +125
°
C
Parameter
Operating point of
vertical magnetic field
Releasing point of
vertical magnetic field
Operating point of horizontal magnetic field
Operating point of horizontal magnetic field
Symbol
BopV
BrpV
BopH
BrpH
BhV, BhH
(*1) Horizontal magnetic flux density is zero.
(*2) Vertical magnetic flux density is zero.
Min.
−
−
0.1
4.0
0.1
4.0
1.5
Typ.
−
−
1.7
1.7
1.7
1.7
3.4
Max.
−
−
4.0
0.1
4.0
0.1
6.8
Unit
mT mT mT mT mT
Note
(*1)
(*1)
(*2)
(*2)
(*1), (*2)
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[AK8777B]
Operational Characteristics
The signal OUTA switches ‘Low’ state (ON) when the magnetic field perpendicular to the marking side of the package exceeds BopV. When the magnetic field is reduces below BrpV, the OUTA goes ‘High’ state (OFF).
Otherwise; that is, in case of the magnetic field strength is greater than BrpV and smaller than BopV; OUTA keeps its status.
Top(Marking)
S
N
Bottom
BrpV
N
Signal OUTA
BhV
0
BopV
S
Figure 2. Switching behavior of the signal OUTA when vertical magnetic field is applied
The signal OUTB switches ‘Low’ state (ON) when the magnetic field parallel to the marking side of the package exceeds BopH. When the magnetic field is reduces below BrpH, the OUTB goes ‘High’ state (OFF). Otherwise; that is, in case of the magnetic field strength is greater than BrpH and smaller than BopH; OUTB keeps its status.
Line Marking
Signal OUTB
Top(Marking)
N
Bottom
VSS pin
S
OUTB pin
BrpH
N
BhH
0
BopH
S
Figure 3. Switching behavior of the signal OUTB when horizontal magnetic field is applied
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[AK8777B]
Sampling cycle
Vertical M.F.D.
BopV
BrpV
0
Sampling
Cycle
M.F.D.
BopV, BopH
0
BrpV, BrpH
Horizontal M.F.D.
BopH
0
BrpH signal OUTA
0 signal OUTB
0
Functional Timing
t t
T
P
: 16.7μs(Typ.)
6μs(Typ.)
Sampling
Cycle
M.F.D.
BopV, BopH
0
BrpV, BrpH t t t t t t t
6μs(Typ.) signal OUTA, signal OUTB
0
*M.F.D. is Magnetic Flux Density
.
Note) V
DD
=12.0V, R
L
=10k
Ω
, C
L
=20pF
50%V
DD t signal OUTA, signal OUTB
0
Figure 4. Timing diagram
50%V
DD t
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Typical Characteristic Data (for reference)
Figure 5. Temperature dependence of sensitivity
Figure 6. Temperature dependence of current consumption
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[AK8777B]
Package
6 5 4
1 2 3
Figure 7. Package dimensions
Note 1) The center of the sensitive area is located within the
φ
0.3mm circle.
1:VDD
2:TAB
3:OUTA
4:OUTB
5:TAB
6:VSS
Note 2) Coplanarity: The differences between standoff of terminals are max. 0.1mm.
Note 3) The sensor part is located 0.71mm(Typ.) from marking surface.
Unit in mm
Material of terminals: Cu alloy
Material of plating for terminals: Sn 100%
Thickness of plating for terminals:10μm (Typ.)
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[AK8777B]
Marking
Line Marking
6 5 4
5YWWL
1 2 3
Figure 8. Marking
GND
Marking is performed by laser
Product name : 5 (AK8777B)
Date code : YWWL
Y : Manufactured year
WW : Manufactured week
L : Lot
Recommended External Circuit
6 5 4
V
DD
V
DD
Output (OUTB)
V
DD
Top View
1 2 3
Output (OUTA)
Figure 9. Recommended external circuit
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[AK8777B]
IMPORTANT NOTICE l These products and their specifications are subject to change without notice.
When you consider any use or application of these products, please make inquiries the sales office of Asahi Kasei
Microdevices Corporation (AKM) or authorized distributors as to current status of the products. l Descriptions of external circuits, application circuits, software and other related information contained in this document are provided only to illustrate the operation and application examples of the semiconductor products. You are fully responsible for the incorporation of these external circuits, application circuits, software and other related information in the design of your equipments. AKM assumes no responsibility for any losses incurred by you or third parties arising from the use of these information herein. AKM assumes no liability for infringement of any patent, intellectual property, or other rights in the application or use of such information contained herein. l Any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. l AKM products are neither intended nor authorized for use as critical components
Note1)
in any safety, life support, or other hazard related device or system
Note2)
, and AKM assumes no responsibility for such use, except for the use approved with the express written consent by Representative Director of AKM. As used here:
Note1) A critical component is one whose failure to function or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and which must therefore meet very high standards of performance and reliability.
Note2) A hazard related device or system is one designed or intended for life support or maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or property. l It is the responsibility of the buyer or distributor of AKM products, who distributes, disposes of, or otherwise places the product with a third party, to notify such third party in advance of the above content and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability for and hold AKM harmless from any and all claims arising from the use of said product in the absence of such notification.
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