SECELECTRONICS SS248KSOT

SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Features




Micropower consumption for battery powered applications
Omnipolar, output switches with absolute value of North or South pole from magnet
Operation down to 2.5V
High sensitivity for direct reed switch replacement applications
3 pin SOT23 (suffix SO)
3 pin SIP (suffix UA)
General Description
The S248 Omnipolar Hall effect sensor IC is fabricated from
mixed signal CMOS technology .It incorporates advanced
chopper-stabilization techniques to provide accurate and stable
magnetic switch points.
The circuit design provides an internally controlled clocking
mechanism to cycle power to the Hall element and analog
signal processing circuits. This serves to place the high
current-consuming portions of the circuit into a “Sleep” mode.
Periodically the device is “Awakened” by this internal logic
and the magnetic flux from the Hall element is evaluated
against the predefined thresholds. If the flux density is above
or below the Bop/Brp thresholds then the output transistor is
driven to change states accordingly. While in the “Sleep” cycle
the output transistor is latched in its previous state. The design
has been optimized for service in applications requiring
extended operating lifetime in battery powered systems.
The output transistor of the S248 will be latched on (Bop) in
the presence of a sufficiently strong South or North magnetic
field facing the marked side of the package. The output will be
latched off (Brp) in the absence of a magnetic field.
Applications

Solid state switch

Handheld Wireless Handset Awake Switch

Lid close sensor for battery powered devices

Magnet proximity sensor for reed switch replacement in low duty cycle applications
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Typical Application Circuit
SEC's pole-independent sensing technique allows for operation
with either a north pole or south pole magnet orientation,
enhancing the manufacturability of the device. The
state-of-the-art technology provides the same output polarity
for either pole face.
It is strongly recommended that an external bypass capacitor be
connected (in close proximity to the Hall sensor) between the
supply and ground of the device to reduce both external noise
and noise generated by the chopper-stabilization technique.
This is especially true due to the relatively high impedance of
battery supplies.
Functional Block Diagram
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Pin Definitions and Descriptions
SOT Pin №
SIP Pin №
Name
Type
Function
1
1
VDD
Supply
Supply Voltage pin
2
3
OUT
Output
Open Drain Output pin
3
2
GND
Ground
Ground pin
Internal Timing Circuit
Current
Period
Iaw
Sample &
Output Latched
Iav
Isp
Awake
Taw:175μs
Sleep Tsl:70ms
0
Time
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Absolute Maximum Ratings
Parameter
Symbol
Value
Units
Supply Voltage(operating)
V DD
6
V
Supply Current
I DD
5
mA
Output Voltage
V OUT
6
V
Output Curent
I OUT
5
mA
Operating Temperature Range
TA
-40 to 85
C
Storage Temperature Rang
TS
-50 to 150
C
-
4000
V
ESD Sensitivity
Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute-maximum rated conditions for
extended periods may affect device reliability.
DC Electrical Characteristics
DC Operating Parameters: T A = 25℃, V DD =2.75V.
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Operating voltage
V DD
Operating
2.5
3
5.5
V
Supply current
I DD
Average
Output Current
I OUT
Saturation Voltage
V SAT
I OUT =1mA
Awake mode time
T AW
Operating
Sleep mode time
T SL
Operating
5
μA
1.0
mA
0.4
V
175
μS
70
mS
Magnetic Characteristics
Output Voltage(V)
3.0
OFF
2.5
2.0
B OPN
1.5
B RPS
B OPS
B RPN
1.0
0.5
0
ON
-80
-60
-40
-20
0
20
40
60
80
Magnetic Flux(Gauss)
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Operating Parameters: T A = 25℃, V DD =2.75V DC .
PARAMETER
Symbol
Min
Type
Max
Units
Operating Point
Bop
-
+/-35
+/-60
Gs
Release Point
Brp
+/-5
+/-21
-
Gs
Hysteresis
Bhys
-
14
-
Gs
Unit
Notes
ESD Protection
Human Body Model (HBM) tests according to: Mil. Std. 883F method 3015.7
Parameter
Symbol
Limit Values
Min
ESD Voltage
Performance
Max
4
V ESD
kV
Characteristics
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Unique Features
CMOS Hall IC Technology
The chopper stabilized amplifier uses switched capacitor techniques to eliminate the amplifier offset voltage, which, in bipolar
devices, is a major source of temperature sensitive drift. CMOS makes this advanced technique possible. The CMOS chip is also
much smaller than a bipolar chip, allowing very sophisticated circuitry to be placed in less space. The small chip size also
contributes to lower physical stress and less power consumption.
Installation Comments
Consider temperature coefficients of Hall IC and magnetics , as well as air gap and life time variations. Observe temperature limits
during wave soldering. Typical IR solder-reflow profile:

No Rapid Heating and Cooling.

Recommended Preheating for max. 2minutes at 150C

Recommended Reflowing for max. 5seconds at 240C
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge
control procedures whenever handling semiconductor products.
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Package Information
Package SO, 3-Pin SOT-23:
Top View
Notes:
1). PINOUT:
Pin 1 VDD
Pin 2 Output
Pin 3 GND
2). All dimensions are in millimeters ;
3
1.50 2.60
1.80 3.00
1
2
1.70
2.10
Side View
End View
2.70
3.10
0.10
0.25
1.00
1.30
0.70
0.90
0.20
MIN
0.00
0.10
0.35
0.50
SOT-23 Package Hall Location
Bottom View of SOT-23 Package
3
Chip
0.56
0.66
0.95
0.80
2
1
1.50
1.40
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Package TSOT-23:
Notes:
1). PINOUT:
Pin 1 VDD
Pin 2 Output
Pin 3 GND
2). All dimensions are in millimeters ;
TSOT-23 Package Hall Location
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Package UA, 3-Pin SIP:
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SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Ordering Information
Part No.
Pb-free
Temperature Code
Package Code
Packing
SS248ESOT
YES
-40°C to 85°C
SOT-23
7-in. reel, 3000 pieces/ reel
SS248EUA
YES
-40°C to 85°C
TO-92
Bulk, 1000 pieces/ bag
SS248KSOT
YES
-40°C to 125°C
SOT-23
7-in. reel, 3000 pieces/ reel
SS248KUA
YES
-40°C to 125°C
TO-92
Bulk, 1000 pieces/ bag
SS248LSOT
YES
-40°C to 150°C
SOT-23
7-in. reel, 3000 pieces/ reel
SS248LUA
YES
-40°C to 150°C
TO-92
Bulk, 1000 pieces/ bag
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