Datasheet A3212 Datasheet (ALLEGRO)

查询A3212EELLT-T供应商查询A3212EELLT-T供应商

2 x 2 mm MLPD

Package A3212EELLT-T

A3212

MICROPOWER, ULTRA-SENSITIVE

HALL-EF FECT SWITCH

The A3212 integrated circuit is an ultra-sensitive, pole in de pen dent Hall-effect
switch with a latched digital output. This sensor is es pe cial ly suited for opera­tion in battery-operated, hand-held equip ment such as cellular and cordless
tele phones, pagers, and palmtop com put ers. A 2.5 volt to 3.5 volt operation and a
unique clocking scheme reduce the average op er at ing power requirements to less
than 15 µW with a 2.75 volt supply.

Unlike other Hall-effect switches, either a north or south pole of suf fi cient
strength will turn the output on; in the absence of a magnetic field, the output
is off. The polarity independence and minimal power requirement allow these
devices to easily replace reed switches for superior reliability and ease of manu­facturing, while eliminating the requirement for signal conditioning.

Data Sheet

27622.61G

Approximate actual size

ABSOLUTE MAXIMUM RATINGS

Supply Voltage, VDD .............................. 5 V

Magnetic Flux Density, B .......... Unlimited

Output Off Voltage, V

Output Current, I

Junction Temperature, TJ ................ +170°C

Operating Temperature, TA

Range 'E-' .................... -40°C to +85°C

Range 'L-' .................. -40°C to +150°C

Storage Temperature Range,

TS .............................. -65°C to +170°C

Caution: These CMOS devices have input
static protection (Class 3) but are still sus­ceptible to damage if exposed to extremely
high static electrical charges.

OUT

...................... 5 V

OUT

........................... 1 mA

Improved stability is made possible through chopper stabilization (dynamic off­set cancellation), which reduces the residual offset voltage normally caused by
device overmolding, temperature de pen den cies, and thermal stress.

This device includes on a single silicon chip a Hall-voltage generator, small-sig­nal amplifier, chopper sta bi li za tion, a latch, and a MOSFET output. Ad vanced
BiCMOS processing is used to take advantage of low-voltage and low-power
requirements, component matching, very low input-offset errors, and small com­ponent geometries.

Four package styles provide magnetically op ti mized solutions for most ap pli ­ca tions. Miniature low-profile surface-mount package types EH and EL
(0.75 and 0.50 mm nominal height) are leadless, LH is a leaded low-profile
SMD, and UA is a three-lead SIP for through-hole mount ing. Each package is
available in a lead (Pb) free version (suffix, –T) with 100% matte tin plated lead­frame. EL package for limited release, engineering samples available.

FEATURES

■ Micropower Operation

■ Operation with North or

■ 2.5 V to 3.5 V Battery Operation

■ Chopper Stabilized

Superior Temperature Stability
Extremely Low Switch-Point Drift
Insensitive to Physical Stress

■ ESD Protected to 5 kV

■ Sol id-State Reliability

■ Small Size

■ Easily Manufacturable with Magnet Pole Independence

South Pole

A3212

MICROPOWER,
ULTRA-SENSITIVE
HALL-EFFECT SWITCH

Use complete part numbers when ordering

Product Selection Guide

Part Number Pb-free

A3212EEHLT – Tape and Reel (3000)

A3212EEHLT–T Yes Tape and Reel (3000)

A3212EELLT–T Yes Tape and Reel (2000)

A3212ELHLT – Tape and Reel (3000)

A3212ELHLT–T Yes Tape and Reel (3000)

A3212EUA – Bulk Pack (500)

A3212EUA–T Yes Bulk Pack (500)

A3212LLHLT – Tape and Reel (3000)

A3212LLHLT–T Yes Tape and Reel (3000)

A3212LUA – Bulk Pack (500)

A3212LUA–T Yes Bulk Pack (500)

*Contact Allegro for additional packaging and handling options.

Packing*

(Units/Pack)

FUNCTIONAL BLOCK DIAGRAM

SUPPLY

Package

Leadless Surface Mount

3-Pin Surface Mount

SIP-3 Through Hole, Straight Lead

3-Pin Surface Mount

SIP-3 Through Hole, Straight Lead

Ambient

Temperature

(°C)

T

A

–40 to 85

–40 to 150

SWITCH

TIMING

LOGIC

OUTPUT

X

& HOLD

DYNAMIC

OFFSET CANCELLATION

2

SAMPLE

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 [phone]

LATCH

GROUND

Dwg. FH-020-5

3212

X

Dwg. PH-016-2

SUPPLY

GROUND

OUTPUT

V

DD

GROUND

NO

CONNECTION

NO

CONNECTION

5

4

6

1

3

2

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

Package Suffix ‘EH’ Pinning

(Leadless Chip Carrier)

Package Suffix ‘EL’ Pinning

(Leadless Chip Carrier)

3

V

DD

12

SUPPLY

GROUND

OUTPUT

Dwg. PH-016-1

Package Suffix ‘LH’ Pinning

(SOT23W)

Package Suffix ‘UA’ Pinning

(SIP)

3

X

V

DD

V

DD

12

SUPPLY

GROUND

Dwg. PH-016-1

OUTPUT

Pinning is shown viewed from branded side.

1

SUPPLY

32

GROUND

Dwg. PH-016

OUTPUT

www.allegromicro.com

3

Copyright © 2002, 2003 Allegro MicroSystems, Inc.

A3212

MICROPOWER,
ULTRA-SENSITIVE
HALL-EFFECT SWITCH

ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless
otherwise specified).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage Range V

Output Leakage Current I

Output On Voltage V

Awake Time t

Period t

DD

OFF

OUT

awake

period

Operating

V

OUT

I

OUT

Duty Cycle d.c. – 0.1 – %

1

= 3.5 V, B

RPN

< B < B

RPS

2.5 2.75 3.5 V

–<1.01.0µA

= 1 mA, VDD = 2.75 V – 100 300 mV

–4590µs

–4590ms

Chopping Frequency f

Supply Current I

DD(EN)

I

DD(DIS)

I

DD(AVG)

C

Chip awake (enabled) – – 2.0 mA

Chip asleep (disabled) – – 8.0 µA

VDD = 2.75 V – 5.1 10 µA

= 3.5 V – 6.7 10 µA

V

DD

– 340 – kHz

NOTES: 1. Operate and release points will vary with supply voltage.

2. B

= operate point (output turns on); B

OPx

= release point (output turns off).

RPx

3. Typical Data is at TA = +25°C and VDD = 2.75 V and is for design information only.

MAGNETIC CHARACTERISTICS over operating voltage and temperature range (unless
otherwise specified).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Operate Points B

Release Points B

Hysteresis B

OPS

B

OPN

RPS

B

RPN

hys

South pole to branded side – 37 55 G

North pole to branded side -55 -40 – G

South pole to branded side 10 31 – G

North pole to branded side – -34 -10 G

|B

- B

OPx

|–5.9–G

RPx

NOTES: 1. Negative flux densities are defined as less than zero (algebraic convention), i.e., -50 G is less than +10 G.

2. B

= operate point (output turns on); B

OPx

= release point (output turns off).

RPx

3. Typical Data is at TA = +25°C and VDD = 2.75 V and is for design information only.

4. 1 gauss (G) is exactly equal to 0.1 millitesla (mT).

4

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 [phone]

3212

60

SWITCH POINTS IN GAUSS

20

0

-20

-40

2.8 3.0 3.2 3.4 3.6

SUPPLY VOLTAGE IN VOLTS

2.4

Dwg. GH-057-2

2.6

B

OPS

-60

40

B

RPS

B

RPN

B

OPN

TA = 25°C

1

0

7.0

AVERAGE SUPPLY CURRENT IN µµ

µµ

A

6.0

5.0

4.0

3.0

2.8 3.0 3.2 3.4 3.6

SUPPLY VOLTAGE IN VOLTS

2.4

Dwg. GH-058-7

2.6

TA = 25°C

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

TYPICAL OPERATING CHARACTERISTICS

SWITCH POINTS

60

B

40

20

OPS

B

RPS

0

-20

SWITCH POINTS IN GAUSS

-40

-60

-50

7.0

A

µµ

6.0

VDD = 2.75 V

B

RPN

B

OPN

-25 25 75 125

0 50 100

AMBIENT TEMPERATURE IN °°°°C

SUPPLY CURRENT

VDD =3.5 V

150

Dwg. GH-027-3

5.0

4.0

AVERAGE SUPPLY CURRENT IN µµ

3.0

-50

-25

www.allegromicro.com

VDD =2.75 V

VDD =2.5 V

100

0255075

AMBIENT TEMPERATURE IN °°°°C

125

Dwg. GH-028-1

15

5

A3212

+V

HALL
VOLTAGE

B

+

—

Dwg. AH-011-2

Dwg. EH-012-1

SAMPLE

& HOLD

X

+V

MICROPOWER,
ULTRA-SENSITIVE
HALL-EFFECT SWITCH

FUNCTIONAL DESCRIPTION

Low Average Power. Internal timing circuitry activates the

sensor for 45 µs and deactivates it for the remainder of the pe­riod (45 ms). A short "awake" time allows for stabilization prior
to the sensor sam pling and data latching on the falling edge of
the timing pulse. The output during the "sleep" time is latched in
the last sampled state. The supply current is not affected by the
output state.

PERIOD

IDD(EN)

"AWAKE"

"SLEEP"

SAMPLE &
OUTPUT LATCHED

IDD(DIS)

0

Dwg. WH-017-2

Chopper-Stabilized Technique. The Hall element can be
considered as a resistor array similar to a Wheatstone bridge. A
large portion of the offset is a result of the mismatching of these
resistors. These devices use a proprietary dynamic offset cancel­lation technique, with an internal high-frequency clock to reduce
the residual offset voltage of the Hall element that is normally
caused by device overmolding, temperature de pen den cies, and
thermal stress. The chopper-stabilizing technique cancels the
mismatching of the resistor circuit by changing the direction of
the current flowing through the Hall plate using CMOS switches
and Hall voltage measurement taps, while maintaing the Hall­voltage signal that is induced by the external magnetic flux. The
signal is then captured by a sample-and-hold circuit and further
processed using low-offset bipolar circuitry. This technique
produces devices that have an extremely stable quiescent Hall
output voltage, are immune to thermal stress, and have precise
recoverability after temperature cycling. A relatively high sam­pling frequency is used for faster signal processing capability
can be processed.

More detailed descriptions of the circuit operation can be found
in: Technical Paper STP 97-10, Monolithic Magnetic Hall Sensor
Using Dynamic Quadrature Offset Cancellation and Technical
Paper STP 99-1, Chopper-Stabilized Amplifiers With A Track-
and-Hold Signal Demodulator.

6

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 [phone]

FUNCTIONAL DESCRIPTION (cont'd)

0

+B

0

Dwg. GH-043-1

-B

OUTPUT ON

5 V

MAX

B

OPS

B

RPS

B

OPN

B

RPN

OUTPUT VOLTAGE

MAGNETIC FLUX

OUTPUT OFF

OUTPUT

Dwg. EH-013-2

0.1 µF

SUPPLY
(3 V BATTERY)

10 pF

50 kΩ

X

V

DD

1

2

3

Operation. The output of this device switches low (turns on)
when a magnetic field perpendicular to the Hall sensor exceeds
the operate point B
output is capable of sinking up to 1 mA and the output voltage
is V

OUT(ON)

release point B

. When the magnetic field is reduced below the

RPS

switches high (turns off). The dif fer ence in the magnetic operate
and release points is the hysteresis (B
built-in hysteresis allows clean switching of the output even
in the presence of external mechanical vibration and electrical
noise.

As used here, negative flux densities are defined as less than
zero (algebraic convention), i.e., -50 G is less than +10 G.

(or is less than B

OPS

(or increased above B

hys

). After turn-on, the

OPN

), the device output

RPN

) of the device. This

3212

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

Applications. Allegro'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 ca pac i tor
be con nect ed (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-sta bi li za tion tech nique. This
is especially true due to the relatively high im ped ance of battery
supplies.

The sim plest form of magnet that will op er ate these devices
is a bar magnet with either pole near the branded surface of the
device. Many oth er meth ods of operation are possible. Ex ten ­sive applications information for Hall-effect sensors is available
in:

• Hall-Effect IC Applications Guide, Application Note 27701;

• Hall-Effect Devices: Soldering, Gluing, Potting, En cap su -
lat ing, and Lead Forming, Application Note 27703.1;

• Soldering of Through-Hole Hall-Sensor Dervices, Application
Note 27703; and

• Soldering of Surface-Mount Hall-Sensor Devices, Application
Note 27703.2.
All are provided at

www.allegromicro.com

www.allegromicro.com

7

A3212

Package Designator 'UA'

1 32

Dwg. MH-011-13

0.0195"

0.50 mm
NOM

BRANDED
SURFACE

ACTIVE AREA DEPTH

0.078"

1.98 mm

0.052"

1.32 mm

A

MICROPOWER,
ULTRA-SENSITIVE
HALL-EFFECT SWITCH

SENSOR LOCATIONS

Package Designator 'EH'

ACTIVE AREA DEPTH

0.013"

0.34 mm
NOM

BRANDED
SURFACE

Package Designator 'LH'

0.035"

0.88 mm

654

A

12

3

Dwg. MH-030

0.062"

1.56 mm

Package Designator 'EL'

ACTIVE AREA DEPTH

0.006"

0.16 mm
NOM

BRANDED
SURFACE

A

.0406

1.03 mm

3

1

2

.0291

0.74 mm

ACTIVE AREA DEPTH

8

0.011"

0.28 mm
NOM

A

1

0.056"

1.42 mm

3

0.033"

0.84 mm

2

Dwg. MH-025-2

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 [phone]

PACKAGE DESIGNATOR ‘EH'

(Reference MO-229C WCED-1)

2.15

.085

1.85

.073

6

3.15

.124

2.85

.112

A

1

3212

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

3.70
BSC

.146

1.25
BSC

1.00
BSC

0.25
BSC

0.30
BSC

.049

0.25
BSC

0.50
BSC

.039

.010

.012

.010

.020

0.30

.012

0.20

.008

0.50

.020

BSC

6

1.142

0.892

1

B

6

.045
.035

0.65

.026

0.45

1.324

1.074

.018

.052
.042

C

1

0.40
BSC

0.95
BSC

.016

.037

0.05

0.00

Dimensions in millimeters
U.S. Customary dimensions (in.) in brackets, for reference only

A

Pin index area

B

Exposed thermal pad

C

ø0.3 Thermal via (optional)

.002
.000

0.20
REF

0.80

0.70

.008

.031
.028

www.allegromicro.com

9

PACKAGE DESIGNATOR ‘EL'

MLPD 3 Contact

2.00

.079

BSC

3

2.00

.079

BSC

A

21

3212

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

1.025
MAX

0.20
REF

0.15
MIN

0.40
NOM

0.32
MIN

.040

.006

.008

.016

.013

1.350
BSC

.053

0.32

.013

0.20

.008

0.50

.053
.043

BSC

.020

0.05

0.80

0.00

0.325
REF

0.70

.013

1

2

B

3

0.325

.013

REF

0.50

3

D

0.138

.005

0.50
BSC

REF

.020

2.40
REF

.094

C

1

0.30

R0.200
REF

.020
.012

.008

1.350

1.100

.002

.031

.000

.028

0.138
REF

0.15
REF

1.025

0.775

.005

0.55

0.45

.006

.040
.031

.022
.018

Dimensions in millimeters
U.S. Customary dimensions (in.)
in brackets, for reference only

A

Pin index area

B

Exposed thermal pad

C

Optional thermal vias, ∅0.30 [.012], pitch 1.2 [.047]

D

Typical pad layout; adjust as necessary to
meet application process requirements

www.allegromicro.com

10

7

0.020

0.012

0.122

0.114

Dimensions in Inches

(for reference only)

3212

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

PACKAGE DESIGNATOR ‘LH’

(SOT23W, fits SC-59A solder-pad layout)

Dimensions in Millimeters

(controlling dimensions)

3.10

2.90

0.50

0.30

0.083

0.073

0.022

REF

0.006

0.000

3

12

0.118

0.106

0.037

BSC

0.039

GAUGE PLANE

SEATING PLANE

0°TO8°

0.0079

0.0050

0.045

0.032

0.028

3

0.094

12

0.010

BSC

Dwg. MA-010-3D in

0.010

MIN

0.55

REF

0.15

0.00

2.10

1.85

3

12

3.00

2.70

0.95

BSC

1.00

12

GAUGE PLANE

SEATING PLANE

0.20

0.127

1.13

0.87

0.70

3

2.40

0°TO8°

0.25

BSC

0.25

MIN

Dwg. MA-010-3D mm

0.03

Dwg. MA-011-3 in

0.95

Dwg. MA-011-3 mm

NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are

measured at the widest point (parting line).

2. Exact body and lead configuration at vendor’s option within limits shown.

3. Height does not include mold gate flash.

4. Where no tolerance is specified, dimension is nominal.

www.allegromicro.com

11

A3212

MICROPOWER,
ULTRA-SENSITIVE
HALL-EFFECT SWITCH

PACKAGE DESIGNATOR ‘UA’

SEE NOTE

45°

0.122

0.117

0.640

0.600

Dimensions in Inches

(controlling dimensions)

0.164

0.159

0.085

123

MAX

0.050

BSC

0.062

0.058

0.031

0.0189

0.0142

0.0173

0.0138

Dwg. MH-014E in

45°

SEE NOTE

Dimensions in Millimeters

(for reference only)

4.17

4.04

45°

3.10

2.97

2.16

123

MAX

16.26

15.24

1.27

BSC

1.57

1.47

45°

0.79

0.44

0.35

0.48

0.36

Dwg. MH-014E mm

NOTES: 1. Tolerances on package height and width represent

allowable mold offsets. Dimensions given are measured
at the widest point (parting line).

2. Exact body and lead configuration at vendor’s option
within limits shown.

3. Height does not include mold gate flash.

4. Recommended minimum PWB hole diameter to clear
transition area is 0.035" (0.89 mm).

5. Where no tolerance is specified, dimension is nominal.

12

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 [phone]

3212

MICROPOWER,

ULTRA-SENSITIVE

HALL-EFFECT SWITCH

www.allegromicro.com

The products described herein are man u fac tured under one or
more of the following U.S. pat ents: 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 de par tures from the detail spec i fi ca tions as may be required
to permit improvements in the per for mance, 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 ap pli anc es, devices, or systems without express written
approval.

The information included herein is believed to be accurate and reli­able. However, Allegro MicroSystems, Inc. assumes no re spon si bil i ty
for its use; nor for any infringements of pat ents or other rights of third
parties that may result from its use.

13