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Электронный компонент: A1242LLHLT-I2-T

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A1242
A1242-DS
Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com
Allegro MicroSystems, Inc.
1
2
3
AB SO LUTE MAX I MUM RAT INGS
Supply Voltage, V
CC
..........................................28 V
Reverse-Supply Voltage, V
RCC
........................ 18 V
Magnetic Flux Density, B .........................Unlimited
Operating Temperature
Ambient,
T
A
, Range E.................. 40C to 85C
Ambient,
T
A
, Range L................ 40C to 150C
Maximum
Junction,
T
J(max)
........................165C
Storage Temperature, T
S
.................. 65C to 170C
Chopper stabilization
Superior temperature stability
Extremely low switchpoint drift
Insensitive to physical stress
Reverse battery protection
Solid-state reliability
Small size
Robust EMC capability
High ESD ratings (HBM)
Two-Wire Chopper-Stabilized Hall Effect Latch
Features and Benefits
Package UA, 3-pin SIP
Package LH, 3-pin Surface Mount
1
2
3
NC
1
2
3
3
1 2
The A1242 Hall effect latch is a two-wire latch especially suited for operation
over extended temperature ranges, from 40 to +150C. Superior high-tempera-
ture performance is made possible through the Allegro
patented dynamic offset
cancellation technique, which reduces the residual offset voltage normally caused
by device overmolding, temperature dependencies, and thermal stress.
The current-switching output technique allows for the reduction in cost in the
wiring harness because only two connections to the sensor are required. The cur-
rent-switching output structure also inherently provides more immunity against
EMC/ESD transients. These sensors have low magnetic thresholds, thereby
enabling more flexibility in the magnetic circuit design.
The Hall effect latch will be in the high output current state in the presence of a
magnetic South Pole field of sufficient magnitude and will remain in this state
until a sufficient North Pole field is present.
The A1242 includes the following on a single silicon chip: a voltage regulator,
Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trig-
ger, and a current source output. Advanced BiCMOS wafer fabrication process-
ing takes advantage of low-voltage requirements, component matching, very low
input-offset errors and small component geometries.
Suffix `L-' devices are rated for operation over a temperature range of 40C
to +150C; suffix `E-' devices are rated for operation over a temperature range
of 40C to +85C. Two A1242 package styles provide magnetically optimized
solutions for most applications. Package LH is a SOT23W, a miniature low-pro-
file surface-mount package, while package UA is a three-lead ultra-mini SIP for
through-hole mounting. Each package is available lead (Pb) free, with 100% matte
tin plated leadframes.
2
A1242-DS
Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com
Allegro MicroSystems, Inc.
Two-Wire Chopper-Stabilized Hall Effect Latch
A1242
Functional Block Diagram
Amp
Regulator
Low-Pass
Filter
GND
VCC
GND
Package UA Only
Clock/Logic
Dyna
mic O
ffse
t
Ca
nce
ll
a
t
i
o
n
Sam
p
le
and

H
o
ld
To All Subcircuits
Terminal List
Name
Description
Number
Package LH Package UA
VCC
Connects power supply to chip
1
1
GND
Ground
3
2,3
NC
No internal connection
2
*Contact Allegro for additional packing options.
Product Selection Guide
Part Number
Packaging*
Mounting
Low Current, I
CC(L)
(mA)
Ambient, T
A
(C)
B
RP(MIN)
(G)
B
OP(MAX)
(G)
A1242ELHLT-I1-T
7-in. reel, 3000 pieces/reel
3-pin SOT23W surface mount
5.0 to 6.9
40 to 85
80
80
A1242ELHLT-I2-T
2.0 to 5.0
A1242EUA-I1-T
Bulk, 500 pieces/bag
3-pin SIP through hole
5.0 to 6.9
A1242EUA-I2-T
2.0 to 5.0
A1242LLHLT-I1-T
7-in. reel, 3000 pieces/reel
3-pin SOT23W surface mount
5.0 to 6.9
40 to 150
A1242LLHLT-I2-T
2.0 to 5.0
A1242LUA-I1-T
Bulk, 500 pieces/bag
3-pin SIP through hole
5.0 to 6.9
A1242LUA-I2-T
2.0 to 5.0
3
A1242-DS
Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com
Allegro MicroSystems, Inc.
Two-Wire Chopper-Stabilized Hall Effect Latch
A1242
DEVICE QUALIFICATION PROGRAM
Contact Allegro for information.
EMC (Electromagnetic Compatibility) PERFORMANCE
Contact Allegro for information.
ELECTRICAL CHARACTERISTICS
over full operating voltage and temperature ranges, unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ.
1
Max.
Units
Electrical Characteristics
Supply Voltage
2
3
V
CC
Operating, T
J
< 165C
3.5
24
V
Supply Current
I
CC(L)
-I1, B < B
RP
5
6.9
mA
-I2, B < B
RP
2
5
mA
I
CC(H)
-I1 and -I2, B > B
OP
12
17
mA
Output Slew Rate
4
dI/dt
R
S
= 100 , C
S
= 20 pF, no bypass capacitor
36
mA/s
Chopping Frequency
f
C
200
kHz
Power-On Time
t
PO
V
CC
> V
CC(MIN)
25
s
Power-On State
5
POS
t
PO
< t
PO(max)
, dV
CC
/ dt > 25 mV / s
I
CC(H)
Supply Zener Clamp Voltage
V
Z(supply)
I
CC
= 20 mA; T
A
= 25C
28
V
Supply Zener Current
6
I
Z(supply)
V
S
= 28 V
20
mA
Reverse Battery Current
I
RCC
V
RCC
= 18 V
2.5
mA
Magnetic Characteristics
7
Operate Point
B
OP
South pole adjacent to branded face of device
5
32
80
G
Release Point
B
RP
North pole adjacent to branded face of device
80
32
5
G
Hysteresis
B
HYS
B
OP
B
RP
40
64
110
G
1
Typical values are at T
A
= 25C and V
CC
= 12 V. Performance may vary for individual units, within the specified maximum and minimum
limits.
2
Maximum voltage must be adjusted for power dissipation and junction temperature; see
Power Derating
section.
3
V
CC
represents the generated voltage between the V
CC
pin and the GND pin.
4
The value of dI is the difference between 90% of I
CC(H)
and 10% of I
CC(L)
, and the value of dt is time period between those two points.
The value of dI/dt depends on the value of the bypass capacitor, if one is used, with greater capacitances resulting in lower rates of
change.
5
For t > t
PO(max)
, and B
RP
< B < B
OP
, POS is undefined.
6
Maximum current limit is equal to the maximum I
CCL(max)
+ 3 mA.
7
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).
4
A1242-DS
Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com
Allegro MicroSystems, Inc.
Two-Wire Chopper-Stabilized Hall Effect Latch
A1242
THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information
Characteristic
Symbol
Test Conditions*
Value Units
Package Thermal Resistance
R
JA
Package LH, minimum-K PCB (single layer, single-sided with
copper limited to solder pads)
228
C/W
Package LH, low-K PCB (single layer, double-sided with
0.926 in
2
copper area)
110
C/W
Package UA, minimum-K PCB (single layer, single-sided with
copper limited to solder pads)
165
C/W
*Additional information available on the Allegro Web site.
Power Derating Curve
T
J(max)
= 165C; I
CC
= I
CC(max)
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
20
40
60
80
100
120
140
160
180
Temperature (C)
M
a
x
i
m
u
m
A
llo
wa
b
l
e

V
CC
(V
)
Minimum-K PCB, Package UA
(R
JA
= 165 C/W)
Minimum-K PCB, Package LH
(R
JA
= 228 C/W)
V
CC(max)
V
CC(min)
Low-K PCB, Package LH
(R
JA
= 110 C/W)
Power Dissipation versus Ambient Temperature
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
20
40
60
80
100
120
140
160
180
Temperature (C)
P
o
w
e
r
D
i
s
s
ipa
t
ion, P
D
(m
W
)
Low-K PCB, Package LH
(R
JA
= 110 C/W)
Min-K PCB, Package LH
(R
JA
= 228 C/W)
Min-K PCB, Package UA
(R
JA
= 165 C/W)
5
A1242-DS
Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com
Allegro MicroSystems, Inc.
Two-Wire Chopper-Stabilized Hall Effect Latch
A1242
Characteristic Data
Supply Current (Low) versus Ambient Temperature
(1242- I1)
5.0
5.2
5.4
5.6
5.8
6.0
6.2
6.4
6.6
6.8
7.0
-50
0
50
100
150
T
A
(C)
I
CC(
L
)
(m
A)
Vcc (V)
24
12
3.75
Supply Current (Low) versus Ambient Temperature
(1242- I2)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
-50
0
50
100
150
T
A
(C)
I
CC(
L
)
(m
A)
Vcc (V)
24
12
3.75
Supply Current (High) versus Ambient Temperature
12
13
14
15
16
17
-50
0
50
100
150
T
A
(C)
I
CC
(
H
)
(m
A
)
Vcc (V)
24
12
3.75
Supply Current (Low) versus Supply Voltage
(A1242-I1)
5.0
5.2
5.4
5.6
5.8
6.0
6.2
6.4
6.6
6.8
7.0
0
5
10
15
20
25
V
CC
(V)
I
CC
(
L
)
(m
A
)
T
A
(C)
-40
25
85
150
Supply Current (Low) versus Supply Voltage
(A1242-I2)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
5
10
15
20
25
V
CC
(V)
I
CC
(
L
)
(m
A
)
T
A
(C)
-40
25
150
Supply Current (High) versus Supply Voltage
12
13
14
15
16
17
0
5
10
15
20
25
V
CC
(V)
I
CC
(
H
)
(m
A
)
T
A
(C)
-40
25
85
150