Allegro A1421 High accuracy analog speed sensor with integrated filter capacitor Datasheet

A1421, A1422, and A1423
High Precision Hall Effect AC-Coupled Differential Sensor IC
with Integrated Filter Capacitor
Features and Benefits
Description
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•
•
•
The A1421, A1422, and A1423 are AC-coupled Hall-effect
sensor ICs which include monolithic integrated circuits that
switch in response to changing differential magnetic fields
created by rotating ring magnets or, when coupled with a
magnet, by ferrous targets. This family of devices also includes
an integrated capacitor that provides the high accuracy of analog
sensing without an external filter capacitor. This reduces cost
and components, while improving the reliability of the final
sensor solution.
•
•
•
•
•
•
•
•
Integrated tracking capacitor
Used for sensing motion of ring magnet or ferrous targets
Wide operating temperature range
Operation with magnetic input signal frequency from
20 Hz to 30 kHz
EMI/ESD-resistant
Large effective air gaps
4.0 to 26.5 V supply operating range
Output compatible with CMOS logic families
Reverse battery protection
Resistant to mechanical and thermal stress
Accurate true zero crossing switchpoint (A1421 only)
High vibration immunity, in running mode (A1423 only)
Package: 4 pin SIP (suffix K)
Magnetic field changes affect the two integrated Hall
transducers and then are differentially amplified on the chip.
Differential design provides immunity to radial vibration,
within the device operating air gap range, by rejection of this
common-mode signal change. Steady-state system offsets
are eliminated using an on-chip differential bandpass filter
with integrated capacitor. This filter also provides relative
immunity to interference from electromagnetic sources. The
device utilizes advanced temperature compensation for the
high-pass filter, sensitivity, and Schmitt trigger switchpoints
to guarantee optimal operation to low frequencies over a wide
range of air gaps and temperatures.
Continued on the next page…
Not to scale
Functional Block Diagram
VS+
VCC
(Pin 1)
Diagnostic
Circuitry
Regulator
Bandpass Filter Integrated
Tracking Capacitor
Dual Hall
Transducers
VOUT
(Pin 2)
Comparator
0.1 uF
Hall
Amp
Gain
Stage
VREF
GND
(Pin 4)
A1421a-DS, Rev. 4
TEST
(Pin 3)
(Required)
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Description (continued)
Each device includes: a voltage regulator, two Hall transducers, temperature compensating circuitry, a low-level amplifier, bandpass filter, Schmitt trigger, and an output driver. The
on-board regulator permits operation with supply voltages from
4.0 to 26.5 V. The output stage can switch 20 mA over the full
frequency response range of the device, and is compatible with
CMOS logic circuits.
The devices in this family differ from each other in their
switchpoint specifications and their switching polarity. The
A1421 has a small hysteresis and asymmetrical switchpoints,
with one switchpoint at the zero-crossing. The A1422 has a small
hysteresis and symmetrical switchpoints, both near the zerocrossing. The A1423 offers high vibration immunity, by means
of its larger hysteresis that establishes symmetrical switchpoints
Continued on the next page…
Product Selection Guide
Output Switching
at BDIFF = 0
Part Number
Switchpoints
Symmetry
BDiff
Increasing
BDiff
Decreasing
BOP(typ)
(G)
BRP(typ)
(G)
BOP(max)+
BRP(min)
(G)
BOP(typ)+
BRP(typ)
(G)
BOP(min)+
BRP(max)
(G)
A1421LK-T
Low (On) to
High (Off)
High (Off) to
Low (On)
15
0
15
15
7.5
A1422LK-T
High (Off) to
Low (On)
Low (On) to
High (Off)
15
–15
0
0
0
A1423LK-T
High (Off) to
Low (On)
Low (On) to
High (Off)
65
–65
0
0
0
*Contact Allegro
Packing*
Bulk, 500
pieces/bag
for additional packing options.
Absolute Maximum Ratings
Characteristic
Symbol
Notes
Supply Voltage
VCC
Refer to Power Derating section
Reverse Supply Voltage
VRCC
Rating
Units
28
V
–18
V
Output Current
IOUT
25
mA
Reverse-Output Current
IROUT
–50
mA
–40 to 150
ºC
Operating Ambient Temperature
TA
Maximum Junction Temperature
TJ(max)
165
ºC
Tstg
–65 to 170
ºC
Storage Temperature
Range L
Pin-out Diagram
Terminal List Table
1
2
3
4
Number
Name
1
VCC
2
VOUT
3
TEST
4
GND
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Description (continued)
further from the zero-crossing. The output polarities are shown
in the Product Selection Guide table.
The device package has an operating ambient temperature range
–40°C to 150°C , and is provided in a 4-pin plastic SIP. Each
package is available in a lead (Pb) free version (suffix, –T) , with
a 100% matte tin plated leadframe.
This variety of options provides flexibility for achieving solutions for a wide range of applications, including automotive
transmission and crankshaft speed sensing.
OPERATING CHARACTERISTICS Valid at TA = – 40ºC to 150ºC, TJ ≤ 165°C; over operational air gap range and VCC within
operating range, unless otherwise noted. Typical operating parameters: VCC = 12 V and TA = 25°C.
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
4.0
12
26.5
V
–
4.2
7.0
mA
–
140
400
mV
–
–
5
μA
VCC = –18 V
–
–
–1
mA
ELECTRICAL CHARACTERISTICS
Supply Voltage
VCC
Supply Current
ICC
Output Saturation Voltage
Output Leakage Current
Operating; TJ < TJ(max)
VOUT(SAT) ISINK = 20 mA
IOFF
VOUT = 24 V, Bdiff = 0
PROTECTION COMPONENT CHARACTERISTICS
Reverse Supply Current
IRCC
Supply Zener Current
IZSupply
VS = 28 V
–
–
10
mA
Supply Zener Clamp Voltage1
VZSupply
ICC = 10 mA, TA = 25°C
28
33
37
V
Output Zener Current
IZOutput
VOUT = 28 V
–
–
3
mA
Output Zener Clamp Voltage
VZOutput
IOUT = 3 mA, TA = 25°C
28
–
–
V
Output Short Circuit Current Limit
IOUTS(lim)
–
–
50
mA
t < tResponse
–
High
–
V
tPO
VCC > VCC(min)
–
4.5
9
ms
tSettling
fBdiff ≥ 100 Hz
RESPONSE CHARACTERISTICS
Power-On State
Power-On Time2,6
Settling
Time3,6
Response Time6
POS
tResponse Equal to tPO + tSettling; fBdiff ≥ 100 Hz
0
–
50
ms
4.5
–
59
ms
Upper Corner Frequency
fCU
–3 dB, single pole
20
–
–
kHz
Lower Corner Frequency
fCL
–3 dB, single pole
–
–
20
Hz
OUTPUT CHARACTERISTICS
Output Rise Time4
tr
RPU = 1 kΩ, COUTC2 = 10 pF
–
–
200
ns
Output Fall Time
tf
RPU = 1 kΩ, ISINK = 20 mA, COUTC2 = 10 pF
–
–
200
ns
Continued on next page.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
OPERATING CHARACTERISTICS, continued Valid at TA = – 40ºC to 150ºC, TJ ≤ 165°C; over operational air gap range and VCC
within operating range, unless otherwise noted. Typical operating parameters: VCC = 12 V and TA = 25°C.
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
0.0
15.0
27.5
G
5.0
15.0
35.0
G
10.0
65.0
100.0
G
–12.5
0.0
7.5
G
–35.0
–15.0
–5.0
G
–100
–65.0
–10.0
G
5
15
35
G
MAGNETIC CHARACTERISTICS5,6
Operate Point
Release Point
Hysteresis
Applied Magnetic Field7
BOP
BRP
BHYS
Bdiff
1421, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p
VOUT switches from low (on) to high (off)
1422, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p
VOUT switches from high (off) to low (on)
1423, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 200 Gp-p
VOUT switches from high (off) to low (on)
1421, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p
VOUT switches from high (off) to low (on)
1422, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p
VOUT switches from low (on) to high (off)
1423, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 200 Gp-p
VOUT switches from low (on) to high (off)
1421, fBdiff = 200 Hz, Bdiff = 50 Gp-p
1422, fBdiff = 200 Hz, Bdiff = 50 Gp-p
–
30
–
G
1423, fBdiff = 200 Hz, Bdiff = 200 Gp-p
–
130
–
G
Differential p-p magnetic field
–
–
1250
G
1I
CC is equivalent
2Time required to
to ICC(max) + 3 mA.
initialize device.
3Time required for the output switchpoints to be within specification.
4Output Rise Time will be dominated by the RC time constant.
5For lower frequencies, the absolute values of B , B , and B
OP
RP
HYS may decrease due to delay induced by the high-pass filter.
6See Definitions of Terms section.
7Exceeding the maximum magnetic field may result in compromised absolute accuracy.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information
Characteristic
Symbol
Test Conditions*
Value
Units
RθJA
Minimum-K PCB (single-sided with copper limited to solder pads)
177
ºC/W
Package Thermal Resistance
*In still air. Additional thermal information available on Allegro Web site.
Power Derating Curve
Maximum Power Dissipation
TJ(max) = 165°C; ICC = ICC(max)
TJ(max) = 165°C; ICC = ICC(max); VCC = VCC(max)
30
28
VCC(max)
24
22
20
18
16
14
Minimum-K PCB
(RQJA = 177 ºC/W)
12
10
8
6
VCC(min)
4
2
0
20
40
60
80
100
120
140
160
180
Power Dissipation, PD (mW)
Maximum Allowable VCC (V)
26
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
M
(R inim
QJ
20
40
60
A
u
= m-K
17 P
7 C
ºC B
/W
)
80
100
120
Temperature (°C)
140
160
180
Definitions of Terms
The following provide additional information about some of the
parameters cited. For additional information, visit the Allegro
Web site at www.allegromicro.com.
Applied Magnetic Field, Bdiff – The differential magnetic flux
density, which is calculated as the arithmetic difference of the
flux densities observed by each of the two Hall elements. fBdiff is
the input signal frequency.
Output Off Switchpoint (Operate Point), BOP – The value of
increasing differential magnetic flux density at which the device
output switches from low to high (A1421) or high to low (A1422
and A1423).
Output On Switchpoint (Release Point), BRP – The value of
decreasing differential magnetic flux density at which the device
output switches from high to low (A1421) or from low to high
(A1422 and A1423).
Power-On Time, tPO – The time needed by the device, after
power is applied, to initialize all circuitry necessary for proper
operation.
Settling Time, tSettling – The time required by the device, after
tPO, and after a valid magnetic signal has been applied, to
provide proper output transitions. Settling time is a function of
magnetic offset, offset polarity, signal phase, signal frequency,
and signal amplitude.
Supply Current (on), ICC(on) – The current draw of the device
with the output transitor is turned on.
Supply Current (off), ICC(off) – The current draw of the device
with the output transitor is turned off.
Response Time, tResponse – The total time required for generating
zero-crossing output transitions after initialization (the sum of
Power-on Time and Settling Time).
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Empirical Results
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
–50
VCC (V)
4.5
12.0
20.0
0
50
100
150
Current (mA)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
–50
ICC(OFF) by VCC
Over TA Range
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
200
TA (ºC)
150
25
–40
0
5
ICC(ON) by TA
ICC(ON) by VCC
Over VCC Range
VCC (V)
4.5
12.0
20.0
0
50
100
150
20
TA (ºC)
150
25
–40
5
10
15
20
VOUT(SAT) by TA
VOUT(SAT) by VCC
Over TA Range; ISINK = 20 mA
VCC (V)
4.5
12.0
20.0
0
50
100
25
Supply Voltage, VCC (V)
Over VCC Range; ISINK = 20 mA
150
Ambient Temperature, TA (ºC)
25
Over TA Range
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0
200
Voltage (mV)
Voltage (mV)
15
Supply Voltage, VCC (V)
Ambient Temperature, TA (ºC)
500
450
400
350
300
250
200
150
100
50
0
–50
10
Ambient Temperature, TA (ºC)
Current (mA)
Current (mA)
Current (mA)
ICC(OFF) by TA
Over VCC Range
200
500
450
400
350
300
250
200
150
100
50
0
0
TA (ºC)
150
25
–40
5
10
15
20
25
Supply Voltage, VCC (V)
Continued on next page.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Simulation Results
Continued on next page.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
7
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Simulation Results, continued
Continued on next page.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
8
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Simulation Results, continued
Continued on next page.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
9
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Simulation Results, continued
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
10
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Device Evaluation: EMC Characterization
Please contact Allegro MicroSystems for EMC performance information.
Test Name
Reference Specification
ESD – Human Body Model*
AEC-Q100-002
ESD – Machine Model
AEC-Q100-003
Conducted Transients
ISO 7637-1
Direct RF Injection
ISO 11452-7
Bulk Current Injection
ISO 11452-4
TEM Cell
ISO 11452-3
*ESD test is done with no external components.
Vs
R2
C1
1
VCC
4
GND
R1
A1421, A1422
or A1423
VOUT
2
C2
TEST
3
Component
R1*
R2
C1
C2
Value
1
100
0.1
0.1
Units
kΩ
Ω
μF
ηF
*Pull-up resistor not required for
protection but for normal operation.
Recommended EMC test circuit. Test circuit recommended
configuration may change after evaluation of first silicon.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
11
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Applications Information
the other a negative hysteresis, BHYS2. Therefore, one comparator
switches at the BOP crossing on an increasing differential signal
and the other switches at the BRP crossing on a decreasing differential signal. The hysteresis on each comparator precludes false
switching on noise or target jitter.
The A1421, A1422, and A1423 are versatile high-precision differential sensor ICs that can be used in a wide range of applications. Proper choice of the target material and shape, magnet
material and shape, and assembly techniques enables large
working air gaps and high switchpoint accuracy over the device
operating temperature range.
The behavior is similar for the A1422 and the A1423. The
switchpoints are as shown in the magnetic charactersitics table,
and the output polarity is inverted. This is illustrated in figure 2,
on the next page.
Device Operation
The device IC contains two integrated Hall transducers that are
used to differentially respond to a magnetic field across the surface of the IC. Referring to figure 1, which shows curves for the
A1421 as an example, the trigger switches the output when the
differential magnetic field crosses the BOP level while increasing
in strength (referred to as the positive direction). In the example,
the A1421 output voltage switches high (off), and switches the
output low (on) when the differential magnetic field crosses BRP
while decreasing (the negative direction).
Start-up
During power-on time, tPO, the output signal, VOUT, is high.
Beyond this time, if the applied magnetic field, Bdiff, is smaller
than BHYS, the switching state and VOUT polarity are indeterminate. VOUT will be valid for Bdiff > BHYS, after the additional
settling time, tSettling, has also elapsed.
Delay
The operation is achieved through the use of two separate comparators. One comparator has a positive hysteresis, BHYS1, and
The bandpass filter induces delay in the output signal, VOUT, relative to the applied magnetic field, Bdiff. Simulation data shown
BRP(typ)1421
BHYS1
B OP(typ)1421
Applied Magnetic
Field, Bdiff

15.0
0.0

BHYS2
Comparator 1, A1421
Comparator 2, A1421
1421 Switching State
Off
Off
On
1421 Output Signal, VOUT
Figure 1. Typical output characteristics with dual comparator operation. The example shown is for the A1421. Characteristics
shown without delay, see characteristic data charts for delay and phase shift contributions.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
12
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
in the Characteristic Data section quantify the effect of the input
signal amplitude on the phase shift of the output. Positive values
of delay indicate a lagging output, while negative values indicate
a leading output.
Typical Circuit
A pull-up resistor, RPU, is required between the supply and output terminals, as shown in figure 3. Also, the auxilliary terminal,
TEST, must be connected externally to the GND terminal.
AC-Coupled Operation
Steady-state magnet and system offsets are eliminated using an
on-chip differential bandpass filter. The upper and lower cut-off
frequencies of this patented filter are set using an internal integrated capacitor. The differential structure of this filter improves
the ability of the IC to reject single-ended noise on the GND
or VCC lines and, as a result, makes the device more resistant
to EMI (electromagnetic interference) typically seen in hostile
remote-sensing environments.
Power Supply Protection
The device contains an on-chip voltage regulator and can operate
over a wide supply voltage range. In applications that operate the
device from an unregulated power supply, transient protection
must be added externally. For applications using a regulated line,
EMI/RFI protection may still be required. The circuit shown
in figure 3 is the most basic configuration required for proper
device operation.
VS
1
0.1 uF
RPU
VCC
4
A1421, A1422
or A1423
VOUT
GND
VOUT
2
TEST
3
Figure 3. Basic application circuit. A pull-up resistor, RPU, is required
with the output driver.
B OP(typ)1423
65.0
BOP(typ)1421, 1422
Applied Magnetic
Field, Bdiff
15.0
0.0
–15.0
BRP(typ)1421
B RP(typ)1422
–65.0
B RP(typ)1423
1421 Switching State
and Output Signal, VOUT
1422 Switching State
and Output Signal, VOUT
1423 Switching State
and Output Signal, VOUT
Off
On
On
On
Off
Off
On
Off
On
t+
Figure 2. Comparative typical output characteristics. This chart illustrates the switchpoints and the output polarities of the A1421,
A1422, and the A 1423. Characteristics shown without delay, see characteristic data charts for delay and phase shift contributions.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
13
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Power Derating
Example
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.)
Reliability for VCC at TA = 150°C, package L-I1, using minimumK PCB
The Package Thermal Resistance, RJA, 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, RJC, is
relatively small component of RJA. 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

T = PD × RJA
TJ = TA + ΔT
(1)
(2)
(3)
Observe the worst-case ratings for the device, specifically:
RJA = 177°C/W, TJ(max) = 165°C, VCC(max) = 26.5 V, and
ICC(max) = 7.0 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 ÷ RJA = 15°C ÷ 177 °C/W = 91 mW
Finally, invert equation 1 with respect to voltage:
VCC(est) = PD(max) ÷ ICC(max) = 91 mW ÷ 7.0 mA = 13 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
RJA. 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 = 4.2 mA, and RJA = 177 °C/W, then:
PD = VCC × ICC = 12 V × 4.2 mA = 50 mW

T = PD × RJA = 50 mW × 177 °C/W = 9°C
TJ = TA + T = 25°C + 9°C = 34°C
A worst-case estimate, PD(max), represents the maximum allowable power level (VCC(max), ICC(max)), without exceeding TJ(max),
at a selected RJA and TA.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
14
A1421, A1422,
and A1423
High Precision Hall Effect AC-Coupled Differential
Sensor IC with Integrated Filter Capacitor
Package K, 4-pin SIP
+0.08
5.21 –0.05
45°
B
E
2.20
E
1.55 ±0.05
1.50
D
NNNN
1.29 E
+0.08
3.43 –0.05
E1
E2
2.16
MAX
Mold Ejector
Pin Indent
Branded
Face
2
3
D Standard Branding Reference View
0.84 REF
N = Device part number
Y = Last two digits of year of manufacture
W = Week of manufacture
For Reference Only; not for tooling use (reference DWG-9010)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
4
14.73 ±0.51
+0.06
0.38 –0.03
+0.07
0.41 –0.05
1
45°
A
1
YYWW
A
Dambar removal protrusion (8X)
B
Gate and tie bar burr area
C
Branding scale and appearance at supplier discretion
D Active Area Depth, .0.42 mm
E Hall elements (E1 and E2); not to scale
1.27 NOM
Copyright ©2004-2009, Allegro MicroSystems, Inc.
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’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
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.
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
15