Datasheet MLX90217L Datasheet (MELEXIS)

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 1

MLX90217

Hall-Effect Cam Sensor

Description

The MLX90217 is a self adjusting digital output ro­tary position gear tooth sensor designed for use in
automotive camshaft sensing as well as other speed
sensing applications. It is designed to be used with a
bias magnet south facing the back (non-marked) side
of the IC. The device has an open collector output
which is short circuit protected.

The MLX90217 is a sophisticated IC featuring an
on-chip 10-bit A/D Converter and logic that acts as a
digital sample and hold circuit. A separate 4-bit A/D
converter provides a fixed hysteresis. The 90217 does
not have a chopper delay. The 90217 uses a single Hall
plate which is immune to rotary alignment problems.
The bias magnet can be from 50 to 400mT.

As the signal is sampled, the logic recognizes an in­creasing or decreasing flux density. The output will
turn on (BOP) after the flux has reached its peak and
decreased by an amount equal to the hysteresis. Simi­larly the output will turn off (BOP) after the flux has
reached its minimum value and increased by an
amount equal to the hysteresis.

Functional Diagram

Pin 1 - VDD (Supply)
Pin 2 - VSS (Ground)
Pin 3 - Output

Amplifier

Voltage

Regulator

ADC

ADC

Logic

Protected

Output

1 2 3

Hall

Plate

10-Bit

4-Bit

Features and Benefits

n Rotary Position Gear Tooth Sensor
n Short Circuit Protection
n On-chip 10 bit A/D Converter
n Self-Adjusting Magnetic Range
n High Speed Operation
n No Chopper Delay
n Zero Speed Detection
n No Rotary Orientation Concerns

Applications

n Camshaft Sensor
n Geartooth Sensor
n Linear Encoder
n Rotary Encoder
n Direction Detection*

*See applications example

Ordering Information

Part No. Temperature Suffix Package Temperature Range

MLX90217 L UA -40oC to 150oC Automotive

Note: Static sensitive device, please observe ESD precautions.

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 2

MLX90217

Hall-Effect Cam Sensor

MLX90217 Electrical Specifications

DC Operating Parameters TA = -40oC to 150oC, VDD = 3.5V to 24V (unless otherwise specified).

Parameter Symbol Test Conditions Min Typ Max Units

Supply Voltage VDD Operating 3.5 - 24 V
Supply Current IDD VDD = 12V 1.5 3.0 4.5 mA
Supply Current IDD VDD = 3.5V to 24V 1 - 6 mA

Leakage Current I

LEAK

V

OUT

= 3.5V to 24V - - 10 µA

Output Current I

OUT

Operating - - 25 mA

Output Saturation Voltage V

SAT

VDD = 12V, I

OUT

= 25mA - - 600 mV

Output Short Circuit Current I

FAULT

Fault 50 100 150 mA

Output Short Circuit Shutdown T

FAULT

Fault 100 - 200 µS

Clock Frequency f

CLK

Operating 300 500 800 kHz
Output Rise Time tr VDD=12V R1 = 880W C1 = 20pf - 400 nS
Output Fall Time tf VDD=12V R1 = 880W C1 = 20pf - 400 nS
Bandwidth BW Operating - - 15 kHz
Thermal Resistance RTH Operating - - 200

o

C/Watt

MLX90217 Magnetic Specifications

DC Operating Parameters TA = -40oC to 150oC, VDD = 3.5V to 24V (Unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Units

Back Bias Range B

BIAS

Operating -30 - 400 mT
Linear Region VDD = 12V 50 - 500 mT
Hysteresis B

hys

VDD = 3.5V to 24V 1.8 3.5 10 mT

Notes: 1 mT = 10 Gauss

Melexis Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Melexis does
not assume any liability arising from the use of any product or application of any product or circuit described herein.

Melexis Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Melexis does
not assume any liability arising from the use of any product or application of any product or circuit described herein.

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 3

MLX90217

Hall-Effect Cam Sensor

500

Flux Density at Hall Plate (mT)

Time

Switch Points
versus
Analog Magnetic Signal
(Cam Lobe)

MLX90217

100

200

300

400

Output
Signal

500

Flux Density at Hall Plate (mT)

Time

Switch Points
versus
Irregular Magnetic Signal
(Worn Gear)

MLX90217

100

200

300

400

Output
Signal

500

Flux Density at Hall Plate (mT)

Time

Switch Points
versus
Regular Magnetic Signal
(New Gear)

MLX90217

100

200

300

400

Output
Signal

Performance Graphs

Absolute Maximum Ratings

Supply Voltage (Operating), VDD 30V
Supply Current (Fault), IDD 50mA
Output Current (Fault), I

OUT

30mA

Output Current (Fault), I

fault

50mA

Output Voltage, V

OUT

30V
Power Dissipation, PD 100mW
Operating Temperature Range, TA 40°C to 150°C
Storage Temperature Range, TS 65°C to 150°C
Maximun Junction Temp, TJ 175°C
ESD Sensitivity +/- 7KV

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 4

MLX90217

Hall-Effect Cam Sensor

Application Notes

Maximum dynamic range is 500 mT. The hysteresis is
fixed at 5.0 mT. Best angular accuracy will be ob­tained when the magnetic circuit provides peak mag­netic flux at the chip near the high end of the linear
range of 500 mT. EMC protection using external com­ponents are recommended. Two possibilities are
shown on the following page. Normally the South pole
faces the unbranded side of the device. A North pole
will enable a test sequence used in factory testing.

Unique Features

The output is reset to the high state at power on
(output driver is off) whatever the field is. The output
only changes after the first min is detected. The reset
state holds no information about the field. If the supply
of the chip is raised slowly, the reset state is not stable.
This has been observed at 0 field but it should be the
same with small and large fields.

Gear tooth sensors often need to be adjusted after the
module is assembled to align the magnet with differen­tial Hall plates or orient with teeth. However the
MLX90217 is “self adjusting” over a wide range of
back bias flux eliminating the need for any trimming
in the application. The magnet may be glued to the
back surface (non branded side) of the IC using a
cyanoacrylate adhesive or suitable epoxy.

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 5

MLX90217

Hall-Effect Cam Sensor

Applications Examples

Edge Sensing (unidirectional)

S N

S N

Lobe Sensing (bidirectional)

Clockwise

Counter Clockwise

CW

CCW

B

RP

B

OP

B

RP

B

OP

B

RP

B

OP

B

OP

Flux Concentration - Tooth Position

Flux Concentration - Valley Position

S N

S N

Severe Environment and

Automotive Protection Circuit

V

DD

In severe cases it may be necessary to include a Zener diode to clamp positive
interference and Schottky diodes to clamp negative excursions.

C2

R2

R1 = 5.6kΩ
R2 =332Ω
C1 = 10nF
C2 = 2.2nF

MLX

90217

V

DD

C1

R1

Output

MLX

90217

Recommended Wiring and
Minimum Protection Circuit

V

DD

C1

R1

Output

R1 = 5.6kΩ
C1 = 10nF

MLX90217 Hall-Effect Cam Sensor Rev 1.7 18/December/00 Page 6

MLX90217

Hall-Effect Cam Sensor

Physical Characteristics

17AB

4936

21 3

17AB

4936

1 2 3

All Dimensions in millimeters

2.13

1.87

0.45

0.41

Marked
Surface

1.53

1.27

UA Hall Plate / Chip Location

UA Marking and Pinout

First line (17) = part number of 90217.
First Line (AB) = series & die revision.

Pin 1 - VDD (Supply)
Pin 2 - VSS (GND)
Pin 3 - Output (open collector)

1.60

1.40

45

o

Typical

4.30

3.90

2.64

2.34

0.84

0.63

3.20

2.80

1.75

1.55

0.48

0.43

0.20

0.00

0.41

0.35

1.30

1.24

2.57

2.51

5

o

Typical

45

o

Typical

0.38

Typical

(see note 3)

15.5

14.5

0.41

0.35

NOTES:
1-Controling Dimension: mm
2-Leads must be free of flash and
plating voids
3-Leads must not arc toward
the rear of package

UA Package Dimensions

Second Line: Lot & Date Code.
(4) = Lot Identification.
(9) = Year 1999.
(36) = Week of Year.

For more information, please contact:

Melexis, Inc.

41 Locke Road
Concord, NH 03301
Phone: [phone] Fax: [phone]
E-mail: [e-mail]
Web: www.melexis.com