Datasheet TLE4923 Datasheet (Siemens)

Dynamic Differential Hall Effect Sensor IC TLE 4923

Bipolar IC

Features

• Advanced performance

• Higher sensitivity

• Symmetrical thresholds

• High piezo resistivity

• Reduced power consumption

• South and north pole pre-induction possible

• AC coupled

• Digital output signal

• Two-wire interface

• Large temperature range

• Large airgap

• Low cut-off frequency

• Protection against reversed polarity

P-SSO-3-6

Type Ordering Code Package

▼ TLE 4923 Q62705-K408 P-SSO-3-6 ▼ New type

The differential Hall effec t sensor TLE 4923 is compatible to the TLE 4921-3U, except for having a 2-wire interface. The TLE 4923 provides high sensitivity, a superior stability over temperature and symme trical thresholds in order to achieve a s table duty cycle. TLE 4923 is particularly suitable for rotational speed detection and timing applications of ferromagnetic toothed wheels such as in anti-lock braking systems, transmissions, crankshafts, etc. The integrate d circuit (based on Hall effect) provides a dig ital signal output with frequency proportional to the speed of rotation. Unlike other rotational sensors differential Hall ICs are not influenced by radial vibration within the effective airgap of the sensor and require no external signal processing.

Semiconductor Group 1 1998-04-29

Pin Configuration

(top view)

1.53

2.67

TLE 4923

Center of

sensitive area ± 0.15

2.5 231

V

GND

S

C

AEP02039

Figure 1

Pin Definitions and Functions Pin No. Symbol Function

1

V

S

Supply voltage 2 GND Ground 3

C

Capacitor

Semiconductor Group 2 1998-04-29

TLE 4923

Protection

Device

1

V

S

Hall-Probes

Figure 2 Block Diagram

2

GND

Internal Reference and Supply

V

(3V)

reg

Highpass-

Amplifier

Filter

C

F

Schmitt-

Trigger

3

AEB01896

Semiconductor Group 3 1998-04-29

TLE 4923

Functional Description

The Differential Hall sensor IC detects the motion and position of ferromagnetic and permanent magnet structure s by mea suring the dif feren tial flux density of the mag netic field. To detect ferromagne tic objects the magnetic field must be provided by a back biasing permanent magnet (south or north pole of the magnet attached to the rear unmarked side of the IC package).

Using an external cap acitor the gene rated Hall vo ltage signal is slowly adju sted via an active high pass filter with low frequency cut-off. This causes the output to switch in to a biased mode after a time constant is e lapsed. The time constant is determi ned by the external capacitor. Filtering avoids aging and temperature influence from Schmitt-trigger input and eliminates device and magnetic offset.

The TLE 4923 can be exploited to detect toothed wheel rotation in a rough environment. Jolts against the toothed wheel and ripple have no influence on the output signal.

The on and off state of the IC are indicated by high and low current consumption.

Circuit Description (see Figure 2)

The TLE 4923 is comprised of a supply voltage referenc e, a pair of Hall probes sp ace d at 2.5 mm, differential amplifier, filter for offset compensation, Schmitt-trigger, and a switched current source.

The TLE 4923 was designed to have a wide range of application parameter variations. Differential fields up to ± 40 mT can be detected without influence to the switching performance. The pre-induction field can either come from a magnetic south or north pole, whereby the field strength up to 500 mT or more will

1)

not influence the switching points

. The improved temperature compensation enables a superior sensitivity and accuracy over the tempera ture range. Finally, the optimized piezo compensation and the integrated dynamic offset compensation enable easy manufacturing and elimination of magnet offsets.

Protection is provided at the input/supply (pin 1) for reverse polarity.

1)

Differential bias fields exceeding ± 20 mT, e. g. caused by a mis aligned magnet, should be avoided.

Semiconductor Group 4 1998-04-29

TLE 4923

Absolute Maximum Ratings Parameter Symbol Limit Values Unit Remarks

min. max.

Supply voltage

V

S

– 18

1)

24 V Capacitor voltage Junction temperature

Junction temperature Junction temperature Junction temperature

Storage temperature Thermal resistance

1)

Reverse current drawn by the d ev ic e < 10 mA

2)

Can be reduced significant ly by f urt her packaging process, e. g. overm olding.

The device is ESD protected up t o 2 kV (HL test proc edure)

V T

T T T

T R

C

j j j j

S

th JA

– 0.3 3 V

150

160

170

190

°C °C °C °C

– 40 150 °C

190 K/W

5000 h 2500 h 500 h 4h

2)

Note: Stresses above those li sted here may cause permanent damage to the device.

Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Operating Range Parameter Symbol Limit Values Unit Remarks

min. max.

Supply voltage Junction temperature Pre-induction

V T B

S

j

0

4.5 18 V – 40 190 °C – 500 500 mT At Hall probe;

independent of magnet orientation

Differential induction ∆

B – 40 40 mT

Note: Unless otherwise noted, all temperatures refer to junction temperature.

In the operating range the functions given in the circuit description are fulfilled.

Semiconductor Group 5 1998-04-29

TLE 4923

AC/DC Characteristics

The device characteristics listed below are guaranteed in the full operating range.

Parameter Symbol Limit Values Unit Test Condition Test

min. typ. max.

Circuit

Supply current

Supply current difference

Supply current ratio

Center of switching points:

B

(∆

+ ∆BRP) / 2

OP

Center of switching points:

B

(∆

+ ∆BRP) / 2

OP

Hysteresis ∆

Current rise time

I

S

I

son

I

SON

I

SOFF

∆

B

∆

B

t

r

m

hy

- I

3.1

8.1

5.0 6.4 8.3 mA 1

soff

/

22.43 1

4.1

10.5

5.3

13.6

mA mA

– 0.5 0 0.5 mT ∆B = 2.0 mT,

f = 200 Hz,

T

1) 2)

≤

j

– 40 °C< 150 °C

– 0.7 0 0.7 mT ∆B = 2.0 mT,

f = 200 Hz,

T

1) 2)

<

j

3)

150 °C< 190 °C

11.52.2mT∆B = 2.0 mT,

f = 200 Hz

0.5 µs2

1 1

2

Current fall time Delay time

4)

Filter input resistance Filter sensitivity to ∆

BS

Filter bias voltage Frequency Resistivity against

mechanical stress (piezo)

6)

t

f

t

dop

t

drp

t

dop

R

C

V f

∆B ∆B

0.5 µs2 25

10

- t

drp

C

35 43 52 kΩ 25 °C ± 2 °C1

15

µs µs µs

f = 10 kHz,

B = 5 mT

∆

2

8.5 mV/mT25 °C ± 2 °C1

C

m Hy

1.6 2.0 2.4 V ∆B = 0 1

5)

– 0.1 – 0.1

10000 Hz ∆B = 5 mT 2

0.1

mT mT

F = 2 N 2

Semiconductor Group 6 1998-04-29

TLE 4923

∆B

m

ILR

C

T()×

S

C

T()

---------------------

=

AC/DC Characteristics (cont’d) The device characteristics listed below are guaranteed in the full operating range.

Parameter Symbol Limit Values Unit Test Condition Test

min. typ. max.

Power Supply Rejection Ratio (PSRR)

V

PSRR

10 V VS modulated

with

f

PSRR

t

r,fPSRR

B =0,

∆

V

,

PSRR

=10kHz,

=1µs,

only 1 transition may occur

1)

For ∆B values larger than ± 10 mT this value may exceed the limits as follows: | ∆Bm | < | 0.05 × ∆B |

2)

Leakage currents at pin 3 sho uld be avoided. The bias shift of Bm caused by a leakage current IL can be

Circuit

7)

2

calculated by: . See also the typical curves on page 17.

3)

Differential pre-induction (e.g. by magnetic misalign m ent ) has t o be s m aller than 20 mT.

4)

For definition see Figure 6.

5)

Depends on filter capacit or CF. The cut-off frequency is given as . The switching points are guaranteed over the whole frequency range, but amplitude modification and phase shift have to be taken

into account due to the 1

6)

For definition see Figure 7.

7)

For definition see Figure 5.

st

order highpass filter.

f

=

1

--------------------------------------- -

2 π×

R

× CF×

C

Note: The listed characteristic s are ensure d over the operating ra nge of the integ rated

circuit. Typical characte ristics speci fy mean val ues expected over the prod uction

Tj

spread. If not o therwise specified, t ypical characteristic s apply at

= 25°C and

the given supply voltage.

Semiconductor Group 7 1998-04-29

TLE 4923

R

180

P

Ω

V

4.7 nF

∆

V

1)

R

C

=

C

Ι

∆

C

Figure 3 Test Circuit 1

V

SZ

Ι

S

1

V

S

1)

V

SLD

V

C

Ι

C

3

C

Ι

C

GND

2

AES01897

V

S

Figure 4 Test Circuit 2

1

V

S

3

C

F

1

µ

F

GND

2

AES01898

R

S

180

Ω

Semiconductor Group 8 1998-04-29

18 V

PSRR

8 V

TLE 4923

t

r f

t

AED02488

Figure 5

∆

B

∆

B

RP

∆

B

OP

t

drp

t

dop

Ι

t

Delay Time between:

drp

and

Ι

LOW to HIGH transient

S

t

Delay Time between

:

dop

S

Ι

and

HIGH to LOW transient

S

Figure 6 Definition of Delay Times (switching points related to initial

measurement @∆

B = 2 mT; f = 200 Hz)

B

∆ = ∆

∆

AED02509

B

RP

∆B=

B

OP

F = 2N

r = 0.5 ± 0.05 mm

IC

4 x d = 1.5

AEA02508

Figure 7 Setup for Piezo Measurements

Semiconductor Group 9 1998-04-29

TLE 4923

Application Notes

Two possible applications are shown in Figure 10 and Figure 11 (Toothed and Magnet Wheel).

Two-wire ap plication i s shown in Figure 12.

Gear Tooth Sensing

In the case of ferrom agnetic too thed wheel a pplicat ions the IC has to be biase d by the south or north pole of a permanent magnet (e.g. SmCo the dimensions 8 mm × 5mm× 3 mm) which should cover both Hall probes.

The maximum air gap depends on:

– the magnetic field strength (magnet used; pre-induction) and – the tooth wheel that is used (dimensions, material, etc.; resulting differential field).

(Vacuumschmelze VX170) with

5

a centered distance

of Hall probes

b Hall probes to

IC surface

L IC surface to

tooth wheel

a=2.5mm b = 0.3 mm

Figure 8 Sensor Spacing

T

d

AEA01260

DIN

d diameter (mm) z number of teeth m module m = d/z (mm) T pitch T = π × m (mm)

N S

b

L

a

AEA01259

Conversion DIN – ASA

m = 25.4 mm/p T = 25.4 mm CP

ASA

p diameter pitch p = z/d (inch)

PD pitch diameter PD =

z/p (inch)

CP circular pitch CP = 1 inch × π/

p

Figure 9 Tooth Wheel Dimensions

Semiconductor Group 10 1998-04-29

Gear Wheel

TLE 4923

Hall Sensor 1

Signal Processing

Circuitry

(N)S

Hall Sensor 2

Permanent Magnet

(S)N

AEA01261

Figure 10 TLE 4923, with Ferromagnetic Toothed Wheel

Magnet Wheel

S

N

Hall Sensor 1

Signal Processing

Circuitry

AEA01262

Figure 11 TLE 4923, with Magnet Wheel

Semiconductor Group 11 1998-04-29

Hall Sensor 2

Two-wire-application

TLE 4923

3

C

F

1

µ

F

Ω

180=

R

typical :

S

Figure 12 Application Circuit

Line

1

V

S

C

1

C

4.7 nF

S

V

S

GND

2

V

SIGNAL

R

S

Sensor Mainframe

AES01899

Semiconductor Group 12 1998-04-29

TLE 4923

N(S)

S(N)

13

B1 B2

Missing ToothWheel Profile

Magnetic Field Difference

B = B2-B1

∆

B

∆

RP

= 0.75 mT

Output Signal

Ι

S

Small Airgap

Large Airgap

B

∆

HY

B

= -0.75 mT∆

OP

Operate point : B2-B1< Release point : B2-B1>

∆∆∆

B

RP

switches the output ON

∆

B

OP

∆

B

switches the output OFF

RP

=

+

B

HYOP

(

high low

current

(

The magnetic field is defined as positive if the south pole of the magnet shows towards the rear side of the IC housing.

AED01900

Figure 13 System Operation

Semiconductor Group 13 1998-04-29

TLE 4923

If not otherwise specified, all curves reflect typical values at Tj = 25 °C and

V

=12V.

S

Supply Current and Supply Current Difference versus Supply Voltage

12

mA

Ι

S

Ι

SON

10

8

Ι

SON

SOFF

6

Ι

SOFF

4

AED02473

Minimum Switching Field versus Frequency

1.2 mT

T

B

min

= 190 C

j

1.0

T

= 150 C

j

0.8

T

= 25 C

j

T

= -40 C

j

0.6

0.4

AED02475

2

0

5

10

15 25

20

V

S

Supply Current and Supply Current Difference versus Temperature

12

mA

Ι

S

Ι

SON

10

8

ΙΙ

SON

SOFF

6

Ι

SOFF

4

2

AED02474

0.2

0

1

10

100 10000

1000

Hz

f

Mean Value of Switching Induction

1.2 mT

∆

B

m

1.0

0.8

0.6

0.4

0.2

∆

B

=

m

f

= 200 Hz

∆

B

OP

2

AED02476

RP

typ

0

400-40

80 200

120

C

T

j

0

400-40

80 200

120

C

T

j

Semiconductor Group 14 1998-04-29

TLE 4923

Hysteresis versus Temperature

1.6 mT

∆

B

HY

1.4

1.2

∆

HY

B

=

RP

∆

B

f

= 200 Hz

1.0

0.8

0.6

0.4 400-40

80 200

B

120

OP

AED02477

typ

C

T

j

Delay Time1) versus Temperature

8

µ

s

t

d

7

6

5

4

3

2

1

0

500-50

100

AED02479

t

dop

t

drp

150

C

T

j

200

Delay Time1) versus Differential Field

6.0 s

µ

5.9

t

d

5.8

5.7

5.6

5.5

5.4

5.3

5.2

5.1

5.0

0

6

42

AED02478

= 10 kHz

f

8

mT

∆

t

dop

t

drp

12

B

Rise and Fall Time versus Temperature

AED02480

150

C

T

j

200

t

140

ns

120

100

80

60

40

20

t

f

t

r

0

500-50

100

1)

Switching points related to init ial m easurement

B = 2 mT, f = 200 Hz

@∆

Semiconductor Group 15 1998-04-29

TLE 4923

Capacitor Voltage versus Temperature

2.5

V

C

2.0

typ

1.5

1.0

0.5

0

500-50

100 200

AED02481

150

C

T

j

Filter Input Resistance versus Temperature

60

k

Ω

R

C

50

typ

40

30

20

10

0

500-50

100 150

AED02483

C

T

j

200

Filter Sensitivity versus Temperature

0

mV/mT

-2

S

C

-4

-6

-8

-10

-12

-14

-16

-18

-20 500-50

typ

100 150

AED02482

= 12 V

V

S

T

j

200

C

t

Delay Time

for Power ON versus

pon

Temperature

0.8

ms/nF

k

0.7

t

= k (nF)

pon

C

F

0.6

0.5

0.4

0.3

0.2

0.1

0

500-50

100

1)

Calculated values for minimum and maximum filter resistance, at room temperature.

C

F

AED02484

1)

max.

min.

150

T

j

1)

200

C

Semiconductor Group 16 1998-04-29

Threshold Shift versus Filter Leakage

8

mT

∆

B

7

m

6

5

4

AED02485

TLE 4923

3

2

1

0

20

40 60 80 100M

+190˚C +100˚C +25˚C

-40˚C

Ω

R

C

Semiconductor Group 17 1998-04-29

Package Outline

P-SSO-3-6

(Plastic Single Small Outline Package)

±0.08

5.16

±0.05

5.38

0.2

max.1.9 1 x 45˚

12.7

±1

0.15 max.

±0.1

1.2

1

-0.1

TLE 4923

±0.05

0.25

±0.08

3.71

±0.06

3.38

±0.1

0.65

(0.25)

1 max.

0.87

±0.05

0.6 max.

±0.05

0.4 123

3.81

±0.4 ±0.3

6.35

±0.3

12.7

d

Branded Side

1.9 max.

±0.05

1.67

4

+0.759-0.5

±0.5

23.8

max.38

±0.5

18

+0.1

0.2

-1

1

±0.5

6

Adhesive Tape

0.25

-0.15

Tape

±0.1

0.5

GPO05960

Hall-Probe

d : Distance chip to upper side of IC

P-SSO-3-6 : 0.3

±0.08

mm

AEA02510

Sorts of Packing

Package outlines for tubes, trays etc. are contained in our

Data Book “Package Information”.

Dimensions in mm

Semiconductor Group 18 1998-04-29