FEELING
TECHNOLOGY
Low-Power Hall Switch
FEATURES
FD2H001Ba-LF
Micro power consumption
2.4V to 5.5V battery operation
Chopper Amplifier based design:
Insensitive to noise and offset caused by process variations, operating temperatures and mechanical stress
Digital output
Programmable output direction
CMOS process
GENERAL DESCRIPTION
FD2H001Ba-LF is a low-power integrated Hall switch designed to sense the applied magnetic flux density and
give a digital output, which indicates the present condition of the magnitude sensed. One example of the
applications is the on/off switch in cellular flip-phones.
The micro power design is especially suitable for battery-operated systems such as cellular phones or laptop
computers, in which power consumption is one major concern. The typical power consumption of FD2H001Ba-LF is
below 10µW at 2.7V.
The magnetic switching points are precise and insensitive to process and temperature variations.
For FD2H001Ba-LF, the output will be at the “low” level if the applied magnetic flux density(North pole) is
stronger than the switching threshold.
For detailed magnetic flux direction please refer to the figure.3
BLOCK DIAGRAM
Bias Generator
Q
Hall Plate
Chopper
Amplifier
Oscillator
Sequencer
Power on
reset
Hysteresis
Control
Figure.1
Rev1.0 Sep. 30, 2008
P.1/FD2H001Ba-LF
FEELING
TECHNOLOGY
PIN CONNECTION
TSOT23
FD2H001Ba-LF
Figure.2
PIN DESCRIPTIONS
Name
I/O
Description
Q
O
Open Drain output
VDD
P
Positive supply
VSS
G
Ground
Legend: I=input, O=output, I/O=input/output, P=power supply, G=ground
2.0 FUNCTIONAL DESCRIPTIONS
Refer to the block diagram (Figure.1), FD2H001Ba-LF is composed of the following building blocks:
Bias generator
The bias generator provides precise, temperature and process insensitive current sources for both the Hall plate
and the chopper amplifier. These current sources in turn guarantee proper operation of the chip and precise
switching thresholds under all kinds of environments specified in the specification.
Oscillator + Sequencer
The built-in oscillator provides the clock signal, which is taken by the sequencer to determine the periods of the
operating phase and the stand-by phase. Typically the operating time is about 60us and the stand-by time is 150ms.
Using such a clocking scheme, the average power consumption is almost equal to that in the stand-by phase, which
is under 10
µ
W at 2.7V.
Power on Reset
Used to detect the power-up ramp and reset the digital circuits to attain correct operation as soon as the power is
ready.
Chopper Amplifier
To achieve a higher resolution the chopper amplifier structure is adopted in this design. Use of this structure
dynamically removes both the offset and flicker noise at the same time.
Hysteresis Control
This block determines the switching threshold of the Hall switch in different situations.
Rev1.0 Sep. 30, 2008
P.2/FD2H001Ba-LF
FEELING
TECHNOLOGY
ABSOLUTE MAXIMUM RATINGS
Parameter
Ambient Operating Temperature
Storage Temperature
DC Supply Voltage
Supply Current
Magnetic Flux Density
Lead Temperature
FD2H001Ba-LF
Conditions
-
-
-
-
-
10sec
Values
min.
-40
-40
2.4
-1
-
max.
85
150
5.5
2.5
unlimited
260
Unit
℃
℃
V
mA
Gauss
℃
Rev1.0 Sep. 30, 2008
P.3/FD2H001Ba-LF
FEELING
TECHNOLOGY
OPERATING CONDITIONS
Parameter
Supply Voltage
Output Voltage
Ambient Temperature
FD2H001Ba-LF
Values
typ.
2.7
2.7
25
Conditions
-
-
-
min.
2.4
-0.3
-40
max.
5.5
5.5
85
Unit
V
℃
V
ELECTRICAL CHARACTERISTICS
Parameter
Average Supply Current
Average Supply Current
(operating phase)
Average Supply Current
(stand-by phase)
Output Saturation Voltage
Output Leakage Current
Operating time
Standby time
Duty cycle
1. operating voltage 2.7V
Conditions
min.
Values
typ.
1
3
1.1
2.5
1
max.
20
Unit
µA
mA
µA
V
µA
µs
ms
%
1
0.1
0.01
60
150
0.04
MAGNETIC CHARACTERISTICS
FD2H011Ba-LF
Parameter
Operate Points ( |B
OP
| )
Hysteresis
Conditions
min.
40
5
Values
typ.
50
10
max.
60
15
Unit
G
G
Rev1.0 Sep. 30, 2008
P.4/FD2H001Ba-LF
FEELING
TECHNOLOGY
MAGNETIC FLUX DIRECTION
FD2H001Ba-LF
Voh
Vol
B
BOP BRP
BRP BOP
0
Figure. 3
Rev1.0 Sep. 30, 2008
P.5/FD2H001Ba-LF
能源基础设施
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