Allegro A3425EL Ultra-sensitive dual-channel quadrature hall-effect bipolar switch Datasheet

A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Package L, 8-pin SOIC
VCC
1
8
No connection
OUTPUTA
2
7
No connection
OUTPUTB
3
6
No connection
GND
4
5
No connection
Package K, 4-pin SIP
1. VCC
2. OUTPUTA
3. OUTPUTB
4. GND
1
2
3
4
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC ....................................... 26.5 V
Reverse-Battery Voltage, VRCC........................ –18 V
Output Off Voltage, VOUTPUT ..............................VCC
Output Sink Current, IOUTPUT(SINK) . Internally Limited
Magnetic Flux Density, B .......................... Unlimited
Operating Temperature
Ambient, TA, Range E.................. –40ºC to 85ºC
Range L................ –40ºC to 150ºC
Maximum Junction, TJ(max)........................165ºC
Storage Temperature, TS .................. –65ºC to 170ºC
A3425DS-Rev. !
The A3425 is a dual-output channel, bipolar switch with two separate Hall-effect
sensor circuits, each providing a separate digital output for speed and direction
signal processing capability. Each sensor circuit has its own independent Hall
element, which are photolithographically aligned to better than 1 µm. Maintaining
accurate mechanical location between the two active Hall elements eliminates the
major manufacturing hurdle encountered in fine-pitch detection applications. The
A3425 is a highly sensitive, temperature-stable magnetic sensing device, which
is ideal for use in ring magnet-based speed and direction systems used in harsh
automotive and industrial environments.
The A3425 monolithic integrated circuit contains two independent Hall effect
switches, located approximately 1 mm apart. The digital outputs are 90º out of
phase so that the outputs are in quadrature with the proper ring magnet design.
This allows for easy processing of speed and direction signals. Extremely lowdrift amplifiers guarantee symmetry between the switches to maintain signal
quadrature. The patented chopper stabilization technique cancels offsets in
each channel, and provides stable operation over the operating temperature and
voltage ranges. An on-chip regulator allows the use of this device over a wide
operating voltage range. Post-assembly factory programming provides sensitive
switchpoints that are symmetrical between the two switches.
The A3425 is available in a plastic 8-pin SOIC surface mount package and a plastic 4-pin SIP, both in two temperature ranges. Each package is available in a lead
(Pb) free version with 100% matte tin plated leadframe.
Features and Benefits
• Two matched Hall effect switches on a single substrate
•
•
•
•
•
•
•
Sensor element spacing approximately 1 mm
Superior temperature stability
3.3 V to 18 V operation
Integrated ESD diode from OUTPUT and VCC pins to GND
High-sensitivity switchpoints
Robust structure for EMC protection
Solid-state reliability
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Functional Block Diagram
VCC
Programmable
Trim
Regulator
8 Bits
Amp
Sample and Hold
Dynamic Offset
Cancellation
4 Bits
OUTPUTA
LowPass
Filter
Output
Drive
Amp
Sample and Hold
Dynamic Offset
Cancellation
4 Bits
OUTPUTB
LowPass
Filter
Output
Drive
GND
Terminal List
Symbol
VCC
OUTPUTA
OUTPUTB
GND
–
Description
Connects power supply to on-chip voltage regulator
Output from first Schmitt circuit
Output from second Schmitt circuit
Ground
No connection
Package
K
1
2
3
4
–
L
1
2
3
4
5, 6, 7, 8
2
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Product Selection Guide
Part Number
A3425EK
Pb-free
Packing*
–
Bulk, 98 pieces/bag
A3425EK-T
Yes
Bulk, 98 pieces/bag
A3425EKTN
–
A3425EKTN-T
A3425EL
Yes
13-in. reel, 4000 pieces/reel
Bulk, 500 pieces/bag
A3425EL-T
Yes
Bulk, 500 pieces/bag
A3425ELTR
–
13-in. reel, 3000 pieces/reel
Yes
13-in. reel, 3000 pieces/reel
A3425LK
–
Bulk, 98 pieces/bag
A3425LK-T
Yes
Bulk, 98 pieces/bag
A3425LKTN
–
A3425LKTN-T
A3425LL
Yes
13-in. reel, 4000 pieces/reel
4-pin SIP through hole
–40ºC to 85ºC
8-pin SOIC surface mount
4-pin SIP through hole
13-in. reel, 4000 pieces/reel
–
Bulk, 500 pieces/bag
A3425LL-T
Yes
Bulk, 500 pieces/bag
A3425LLTR
–
13-in. reel, 3000 pieces/reel
Yes
13-in. reel, 3000 pieces/reel
A3425LLTR-T
Ambient, TA
13-in. reel, 4000 pieces/reel
–
A3425ELTR-T
Mounting
–40ºC to 150ºC
8-pin SOIC surface mount
*Contact Allegro for additional packing options.
3
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
OPERATING CHARACTERISTICS Valid over operating temperature ranges unless otherwise noted; typical data applies to
VCC = 12 V, and TA = 25ºC
Characteristic
Symbol
Test Conditions
Min. Typ.
Max
Units
ELECTRICAL CHARACTERISTICS
Supply Voltage1
VCC
Output Leakage Current
IOUTPUT(OFF)
Operating; TA ≤ 150°C
3.3
–
18
V
Either output
–
<1
10
µA
Output Rise Time
tr
CLOAD = 20 pF, RLOAD = 820 Ω
–
110
–
ns
Output Fall Time
tf
CLOAD = 20 pF, RLOAD = 820 Ω
–
55
–
ns
ICC(OFF)
B < BRP(A) ,B < BRP(B)
–
3.5
6.0
mA
ICC(ON)
B > BOP(A) ,B > BOP(B)
–
4.0
6.0
mA
Both outputs; IOUTPUT(SINK) = 20 mA; B > BOP(A),
B > BOP(B)
–
160
500
mV
–
–
20
mA
Supply Current
Low Output Voltage
VOUTPUT(ON)
Output Sink Current
Output Sink Current,
IOUTPUT(SINK)
Continuous2
Output Sink Current, Peak3
Chopping Frequency
IOUTPUT(SINK)C
TJ < TJ(max) ,VOUTPUT = 12 V
–
–
70
mA
IOUTPUT(SINK)P
t < 3 seconds
–
–
220
mA
–
340
–
kHz
fC
TRANSIENT PROTECTION CHARACTERISTICS
Supply Zener Voltage
VZ
ICC = 15 mA
28
33
37
V
Supply Zener Current4
IZ
VS = 28 V
–
–
9.0
mA
VRCC = –18 V, TJ < TJ(max)
–
2
15
mA
Reverse-Battery Current
IRCC
Continued on the next page...
4
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
OPERATING CHARACTERISTICS (continued) Valid over operating temperature ranges unless otherwise noted; typical
data applies to VCC = 12 V, and TA = 25ºC
Characteristic
MAGNETIC CHARACTERISTICS, K
Symbol
Test Conditions
Min. Typ.
Max
Units
Package5
Operate Point: B > BOP
BOP(A), BOP(B)
–
7
35
G
Release Point: B < BRP
BRP(A), BRP(B)
–35
–7
–
G
BHYS(A), BHYS(B)
5
16
40
G
SYMA, SYMB
–40
–
40
G
Operate Symmetry: BOP(A) – BOP(B)
SYMAB(OP)
–30
–
30
G
Release Symmetry: BRP(A) – BRP(B)
SYMAB(RP)
–30
–
30
G
Hysteresis: BOP(A) – BRP(A),
BOP(B) – BRP(B)
Symmetry: Channel A, Channel B,
BOP(A) + BRP(A), BOP(B) + BRP(B)
MAGNETIC CHARACTERISTICS, L Package5
Operate Point: B > BOP
BOP(A), BOP(B)
–
7
30
G
Release Point: B < BRP
BRP(A), BRP(B)
–30
–7
–
G
BHYS(A), BHYS(B)
5
14
35
G
SYMA, SYMB
–35
–
35
G
Operate Symmetry: BOP(A) – BOP(B)
SYMAB(OP)
–25
–
25
G
Release Symmetry: BRP(A) – BRP(B)
SYMAB(RP)
–25
–
25
G
Hysteresis: BOP(A) – BRP(A),
BOP(B) – BRP(B)
Symmetry: Channel A, Channel B,
BOP(A) + BRP(A), BOP(B) + BRP(B)
1
When operating at maximum voltage, never exceed maximum junction temperature, TJ(max). Refer to power derating curve charts.
Device will survive the current level specified, but operation within magnetic specification cannot be guaranteed.
3 Short circuit of the output to VCC is protected for the time duration specified.
4 Maximum specification limit is equivalent to I
CC(max) + 3 mA.
5 Magnetic flux density, B, is indicated as a negative value for north-polarity magnetic fields, and as a positive value for south-polarity
magnetic fields. This so-called algebraic convention supports arithmetic comparison of north and south polarity values, where the
relative strength of the field is indicated by the absolute value of B, and the sign indicates the polarity of the field (for example, a –100
G field and a 100 G field have equivalent strength, but opposite polarity).
2
EMC
Contact Allegro MicroSystems for EMC performance.
5
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information
Characteristic
Symbol
Test Conditions
Value Units
Package K, minimum-K PCB (single-sided with copper limited to
177 ºC/W
solder pads)
Package L, minimum-K PCB (single-sided with copper limited to
140 ºC/W
solder pads)
Package L, high-K PCB (multilayer with significant copper
80
ºC/W
areas, based on JEDEC standard)
RθJA
Package Thermal Resistance
Maximum Allowable VCC (V)
Power Derating Curve
TJ(max) = 165ºC; ICC = ICC(max)
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
VCC(max)
High-K PCB, Package L
(RθJA = 80 ºC/W)
Minimum-K PCB, Package L
(RθJA = 140 ºC/W)
Minimum-K PCB, Package K
(RθJA = 177 ºC/W)
VCC(min)
20
40
60
80
100
120
140
160
180
Temperature (ºC)
Power Dissipation, PD (m W)
Power Dissipation versus Temperature
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
H
(R igh
θJ
A
-K
= PC
80 B,
ºC Pa
/W ck
) ag
Min
(R imum
e
θJA
L
= 1 -K P
40 CB
ºC , Pa
/W
cka
Min
)
ge
(R imumL
KP
θJA =
177 CB,
Pac
ºC/
W)
kag
eK
20
40
60
80
100
120
140
Temperature, TA (°C)
160
180
6
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Functional Description
Chopper-Stabilized Technique
When using Hall effect technology, a limiting factor
for switchpoint accuracy is the small signal voltage
developed across the Hall element. This voltage is
disproportionally small relative to the offset that can
be produced at the output of the Hall device. This
makes it difficult to process the signal and maintain
an accurate, reliable output over the specified temperature and voltage range.
Chopper stabilization is a unique approach used
to minimize Hall offset on the chip. The patented
Allegro technique, dynamic quadrature offset cancellation, removes key sources of the output drift
induced by thermal and mechanical stress. This offset
reduction technique is based on a signal modulationdemodulation process. The undesired offset signal is
separated from the magnetically induced signal in the
frequency domain through modulation. The subsequent demodulation acts as a modulation process for
the offset, causing the magnetically-induced signal to
recover its original spectrum at the baseband level,
while the dc offset becomes a high-frequency signal.
Then, using a low-pass filter, the signal passes while
the modulated dc offset is suppressed.
The chopper stabilization technique uses a 170 kHz
high-frequency clock. The Hall element chopping
occurs on each clock edge, resulting in a 340 kHz
chop frequency. This high-frequency operation allows
for a greater sampling rate, which produces higher
accuracy and faster signal processing capability. This
approach desensitizes the chip to the effects of thermal and mechanical stress. The disadvantage to this
approach is that jitter, also known as 360° repeatability,
can be induced on the output signal. The sample-andhold process, used by the demodulator to store and
recover the signal, can slightly degrade the signal-tonoise ratio. This is because the process generates replicas of the noise spectrum at the baseband, causing a
decrease in jitter performance. However, the improvement in switchpoint performance, resulting from the
reduction of the effects of thermal and mechanical
stress, outweighs the degradation in the signal-to-noise
ratio.
This technique produces devices that have an
extremely stable quiescent Hall element output voltage, are immune to thermal stress, and have precise
recoverability after temperature cycling. This technique is made possible through the use of a BiCMOS
process, which allows the use of low-offset and
low-noise amplifiers in combination with high-density
logic integration and sample-and-hold circuits. This
process is illustrated in the following diagram.
Amp
Sample and Hold
Regulator
LowPass
Filter
Chopper stabilization circuit (dynamic quadrature offset cancellation)
7
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Typical Applications Operation
Switch to High
VOUTPUT(OFF)
Switch to Low
VOUTPUT
V+
VOUTPUT(ON)(sat)
BRP
BOP
B+
BHYS
Output voltage in relation to sensed magnetic flux density. Output on
each channel independently follows the same pattern of transition
through BOP followed by transition through BRP.
M agnetic Field
Sensor A
M agnetic Field
Sensor B
Output Sensor A
Output Sensor B
Quadrature output signal configuration. The outputs of the two output
channels have a phase difference of 90º when used with a properly
designed magnet that has an optimal pole pitch of twice the Hall element spacing of 1.0 mm.
8
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Typical Applications Circuits
This device requires minimal protection circuitry
during operation with a low-voltage regulated line.
The on-chip voltage regulator provides immunity
to power supply variations between 3.3 and 18 V.
Because the device has open-collector outputs, pullup resistors must be included.
If protection against coupled and injected noise is
required, then a simple low-pass filter on the supply
(RC) and a filtering capacitor on each of the outputs
may also be needed, as shown in the unregulated
supply diagram.
For applications in which the device receives its
power from unregulated sources, such as a car battery, full protection is generally required to protect the
device against supply-side transients. Specifications
for such transients vary for each application, so the
design of the protection circuit should be optimized
for each application.
For example, the circuit shown in the unregulated
supply diagram includes a Zener diode that offers
high voltage load-dump protection and noise filtering
by means of a series resistor and capacitor. In addition, it includes a series diode that protects against
high-voltage reverse battery conditions.
VOUTPUTB
VOUTPUTA
2
OUTPUTA
VSupply
1
A3425
VCC
OUTPUTB
3
GND
0.1 uF
4
Regulated supply
VOUTPUTB
VOUTPUTA
2
OUTPUTA
VSupply
1
A3425
VCC
OUTPUTB
3
100 Ω
GND
4
0.1 uF
Unregulated supply
9
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Typical Thermal Performance
The device must be operated below the maximum junction
temperature of the device, TJ(max). Under certain combinations of
peak conditions, reliable operation may require derating supplied power or improving the heat dissipation properties of the
application. This section presents a procedure for correlating
factors affecting operating TJ. (Thermal data is also available on
the Allegro MicroSystems Web site.)
The Package Thermal Resistance, RθJA, is a figure of merit summarizing the ability of the application and the device to dissipate
heat from the junction (die), through all paths to the ambient air.
Its primary component is the Effective Thermal Conductivity,
K, of the printed circuit board, including adjacent devices and
traces. Radiation from the die through the device case, RθJC, is
relatively small component of RθJA. Ambient air temperature,
TA, and air motion are significant external factors, damped by
overmolding.
The effect of varying power levels (Power Dissipation, PD), can
be estimated. The following formulas represent the fundamental
relationships used to estimate TJ, at PD.
PD = VIN × IIN
(1)
∆T = PD × RθJA
(2)
TJ = TA + ∆T
(3)
Example: Reliability for VCC at TA = 150°C, package L, using
minimum-K PCB
Observe the worst-case ratings for the device, specifically:
RθJA = 140 °C/W, TJ(max) = 165°C, VCC(max) = 18 V, and
ICC(max) = 6 mA.
Calculate the maximum allowable power level, PD(max). First,
invert equation 3:
∆Tmax = TJ(max) – TA = 165 °C – 150 °C = 15 °C
This provides the allowable increase to TJ resulting from internal
power dissipation. Then, invert equation 2:
PD(max) = ∆Tmax ÷ RθJA = 15°C ÷ 140 °C/W = 107 mW
Finally, invert equation 1 with respect to voltage:
VCC(est) = PD(max) ÷ ICC(max) = 107 mW ÷ 6 mA = 18 V
The result indicates that, at TA, the application and device can
dissipate adequate amounts of heat at voltages ≤VCC(est).
Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reliable operation between VCC(est) and VCC(max) requires enhanced
RθJA. If VCC(est) ≥ VCC(max), then operation between VCC(est) and
VCC(max) is reliable under these conditions.
For example, given common conditions such as: TA= 25°C,
VCC = 12 V, ICC = 4 mA, and RθJA = 140 °C/W, then:
PD = VCC × ICC = 12 V × 4 mA = 48 mW
∆T = PD × RθJA = 48 mW × 140 °C/W = 7°C
TJ = TA + ∆T = 25°C + 7°C = 32°C
A worst-case estimate, PD(max), represents the maximum allowable power level (VCC(max), ICC(max)), without exceeding TJ(max),
at a selected RθJA and TA.
10
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Electrical Operating Characteristics, Package L
ICC(off)
8
8
7
7
6
6
5
-40°C
4
25°C
3
150°C
2
Current (mA)
Current (mA)
ICC(off)
1
3.3 V
18 V
5
4
3
2
1
0
0
0
5
10
15
-50
20
0
50
ICC(on)
150
200
ICC(on)
8
8
7
7
6
6
5
-40°C
4
25°C
3
150°C
2
Current (mA)
Current (mA)
100
Temperature (°C)
VCC (V)
1
5
3.3 V
4
18 V
3
2
1
0
0
5
10
15
0
20
-50
0
50
100
150
200
Temperature (°C)
VCC (V)
Output Saturation Voltage
VCC = 3.3 V, Isink = 20 mA
500
Vsat (mV)
400
Ch. A
300
Ch. B
200
100
0
-50
0
50
100
150
200
Temperature (°C)
11
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package L
Channel A, BOP and BRP
Channel A, BOP and BRP
30
30
20
BOP
10
0
-40°C
25°C
150°C
BRP
-10
-20
-30
0
5
10
15
Switchpoint (G)
Switchpoint (G)
20
0
0
100
150
200
Channel B, BOP and BRP
30
20
BOP
10
0
-40°C
25°C
150°C
BRP
-10
Switchpoint (G)
20
Switchpoint (G)
50
Temperature (°C)
30
-20
0
5
10
15
0
3.3 V
12 V
18 V
BRP
-10
-20
-30
-50
20
BOP
10
0
50
100
150
200
Temperature (°C)
VCC (V)
Channels A and B, Hysteresis
Channels A and B, Hysteresis
30
30
25
25
20
-40°C
25°C
150°C
15
10
BOP - BRP (G)
BOP - BRP (G)
18 V
-20
Channel B, BOP and BRP
20
3.3 V
12 V
18 V
15
10
5
5
0
12 V
BRP
VCC (V)
-30
3.3 V
-10
-30
-50
20
BOP
10
0
5
10
15
VCC (V)
20
0
-50
0
50
100
150
200
Temperature (°C)
Additional magnetic characteristics on next page
12
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package L (continued)
BOP Symmetry
BOP Symmetry
30
30
20
10
-40°C
0
25°C
150°C
-10
-20
-30
0
5
10
15
Ch. A - Ch. B (G)
Ch. A - Ch. B (G)
20
12 V
0
18 V
-10
-20
-30
-50
20
3.3 V
10
0
VCC (V)
20
20
10
-40°C
0
25°C
150°C
-10
-20
10
15
VCC (V)
20
Ch. A - Ch. B (G)
Ch. A - Ch. B (G)
30
5
150
200
BRP Symmetry
BRP Symmetry
0
100
Temperature (°C)
30
-30
50
10
3.3 V
0
12 V
-10
18 V
-20
-30
-50
0
50
100
150
200
Temperature (°C)
Additional magnetic characteristics on next page
13
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package L (continued)
Ch. A Symmetry
30
30
20
20
10
-40°C
0
25°C
150°C
-10
-20
BOP + BRP (G)
BOP + BRP (G)
Ch. A Symmetry
-30
0
5
10
15
10
12 V
-10
18 V
-20
-30
-50
20
3.3 V
0
0
VCC (V)
20
20
10
10
-40°C
0
25°C
-10
150°C
-20
-30
VCC (V)
15
20
BOP + BRP (G)
BOP + BRP (G)
30
10
150
200
Ch. B Symmetry
30
5
100
Temperature (°C)
Ch. B Symmetry
0
50
3.3 V
0
12 V
-10
18 V
-20
-30
-50
0
50
100
150
200
Temperature (°C)
14
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Electrical Operating Characteristics, Package K
ICC(off)
8
8
7
7
6
6
5
-40°C
4
25°C
3
150°C
2
Current (mA)
Current (mA)
ICC(off)
1
3.3 V
18 V
5
4
3
2
1
0
0
0
5
10
15
-50
20
0
50
ICC(on)
150
200
ICC(on)
8
8
7
7
6
6
5
-40°C
4
25°C
3
150°C
2
1
Current (mA)
Current (mA)
100
Temperature (°C)
VCC (V)
5
3.3 V
4
18 V
3
2
1
0
0
5
10
15
0
20
-50
0
50
100
150
200
Temperature (°C)
VCC (V)
Output Saturation Voltage
VCC = 3.3 V, Isink = 20 mA
500
Vsat (mV)
400
Ch. A
300
Ch. B
200
100
0
-50
0
50
100
150
200
Temperature (°C)
15
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package K
Channel A, BOP and BRP
Channel A, BOP and BRP
30
30
20
BOP
10
0
-40°C
25°C
150°C
BRP
-10
-20
-30
0
5
10
15
Switchpoint (G)
Switchpoint (G)
20
0
0
100
150
200
Channel B, BOP and BRP
30
20
BOP
10
0
-40°C
25°C
150°C
BRP
-10
Switchpoint (G)
20
Switchpoint (G)
50
Temperature (°C)
30
-20
0
5
10
15
0
3.3 V
12 V
18 V
BRP
-10
-20
-30
-50
20
BOP
10
0
50
100
150
200
Temperature (°C)
VCC (V)
Channels A and B, Hysteresis
Channels A and B, Hysteresis
30
30
25
25
20
-40°C
25°C
150°C
15
10
BOP - BRP (G)
BOP - BRP (G)
18 V
-20
Channel B, BOP and BRP
20
3.3 V
12 V
18 V
15
10
5
5
0
12 V
BRP
VCC (V)
-30
3.3 V
-10
-30
-50
20
BOP
10
0
5
10
15
VCC (V)
20
0
-50
0
50
100
150
200
Temperature (°C)
Additional magnetic characteristics on next page
16
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package K (continued)
BOP Symmetry
BOP Symmetry
30
30
20
10
-40°C
0
25°C
150°C
-10
-20
-30
0
5
10
15
Ch. A - Ch. B (G)
Ch. A - Ch. B (G)
20
12 V
0
18 V
-10
-20
-30
-50
20
3.3 V
10
0
VCC (V)
20
20
10
-40°C
0
25°C
150°C
-10
-20
10
15
VCC (V)
20
Ch. A - Ch. B (G)
Ch. A - Ch. B (G)
30
5
150
200
BRP Symmetry
BRP Symmetry
0
100
Temperature (°C)
30
-30
50
10
3.3 V
0
12 V
-10
18 V
-20
-30
-50
0
50
100
150
200
Temperature (°C)
Additional magnetic characteristics on next page
17
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Magnetic Operating Characteristics, Package K (continued)
Ch. A Symmetry
30
30
20
20
10
-40°C
0
25°C
150°C
-10
-20
BOP + BRP (G)
BOP + BRP (G)
Ch. A Symmetry
-30
0
5
10
15
10
12 V
-10
18 V
-20
-30
-50
20
3.3 V
0
0
VCC (V)
30
30
20
20
10
-40°C
0
25°C
-10
150°C
-20
-30
5
10
VCC (V)
100
150
200
Ch. B Symmetry
15
20
BOP + BRP (G)
BOP + BRP (G)
Ch. B Symmetry
0
50
Temperature (°C)
10
3.3 V
0
12 V
-10
18 V
-20
-30
-50
0
50
100
150
200
Temperature (°C)
18
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Package K, 4-pin SIP
19
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
Package L, 8-pin SOIC
20
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
A3425
Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch
The products described herein are manufactured under one
or more of the following U.S. patents: 5,045,920; 5,264,783;
5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319;
5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other
patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time
to time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability,
or manufacturability of its products. Before placing an order, the
user is cautioned to verify that the information being relied upon is
current.
Allegro products are not authorized for use as critical components in life-support devices or systems without express written
approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other
rights of third parties which may result from its use.
Copyright © 2005, Allegro MicroSystems, Inc.
21
A3425DS-Rev. !
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
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