Integrated Current Sensor FHS AH 600
Definition
The FHS AH field sensor is a contact-less, open loop surface mounted device based on the Hall effectprinciple. The device uses an Integrated Magnetic Circuit (IMC) combined with improved sensitivity, offset
and temperature stress compensation allowing high accuracy and low-noise current sensing. With 160
kHz bandwidth and fast delay time < 2 µs, the FHS AH sensor is highly suitable for DC, AC, pulsed andmixed current measurements. Contact-less current sensing solution allows no additional power losses andhigh dielectric insulation between the primary circuit and transducer electronics. By using an Integrated
Magnetic Circuit (IMC), the FHS AH removes the need for an external magnetic core, offers flexibility incompact design and makes it the perfect solution to measure current flowing through a conductor such asa PCB track.

Main features & advantages

Typical applications● Hall effect current sensor with Integrated Magnetic
Concentrator (IMC)● Small drives● Magnetic field measurement range ±3.3 mT● Motor control● Supply voltage 5 V

● BMS
● UPS

● Low power consumption● Operating temperature range : −40 ... 125 °C● High bandwidth: 160 kHz● HVAC● White goods● PCB track current sensing.

● Excellent linearity < 0.5 % Full Scale● Sensitivity error < 1 % from −40 ... 125 °C● Insulated current measurement● Small footprint with standard SOIC8 surface mount PCB● Low cost, Small size
● Internal reference voltage.

Figure 1: F
 HS AH package - SOIC-8

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FHS AH 600
Application circuit and pinout
R E ref
RE
UC

Cref

Uref

UE OCD

Uout

OCDI

GND

OCDE

UC

NC

R I_OCD

R E_OCD

Cout

CREF

CSupply

B
Figure 2: Application circuit

Table 1: Pin definition
Pin#

Name

Description

1

Uref

Rerence voltage

2

Uout

Output voltage

3

GND

Ground terminal

4UC

Supply voltage

5NC

Not connected or GND

6

OCDE

External OCD

7

OCDI

Internal OCD

8

UE OCD

External OCD threshold voltage terminal

Polarity
Uout − Uref is positive following the direction of the arrow.

Table 2: External circuit components
External circuit example#

Unit

Value

Comment

Csupply

nF

47

< 100

Cout

nF

4.7

<6

Cref

nF

4.7

RI OCD

kΩ

4.7

< 50

RE OCD

kΩ

4.7

< 50

RE

kΩ

100

RE refkΩ

100

Csupply, Cout and Cref should be mounted as close as to the pins.
Ideally, RE ref + RE should have a value around 200 kΩ due to current limitation on Uref.
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FHS AH 600
Absolute maximum ratings
Parameter

SymbolUnit

RatingAmbient operating temperatureTA°C−40 ... +125

Ambient storage temperature

TA st

°C

−55 ... +165

Maximum junction temperature

TJ max°C

165

Output sink current

mA

−50

Output source current

mA

25

T

±3

Magnetic flux density

Bmax

Absolute maximum ratings apply at 25 °C unless otherwise noted.
Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum ratings for extented periods may degrade reliability.

Environmental and mechanical characteristics
Parameter

Symbol

Unit

Value

Maximum supply voltage

UC maxV

8Electrostatic discharge voltage (HMB-Human Body Model)

UESD HBM

kV

2

m

g

0.08

Mass

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FHS AH 600
Electrical data
At TA = 35 °C, UC = +5 V, RL = 100 kΩ unless otherwise noted (see Definition of typical, minimum and maximum values paragraph).

Parameter

Symbol

Unit

Min

Typ

Max

DC supply voltage

UC

V

4.5

5

5.5

−40 °C ... 125 C

Current consumption

IC

mA

12

14

19

−40 °C ... 125 C;
without RL

Magnetic flux density measuring
range

BM

mT

Output voltage in a flux density B

Uout

V

0.5

4.5

Linearity error 0 … BMεL

% of BM−0.5

0.5

Nominal sensitivity

SN

mV/mT

Sensitivity error

εS

%

−1

Temperature coefficient of S

TCS

ppm/K

−200

Lifetime sensitivity drift

SL%Internal reference voltage @ B = 0 T

UI ref

V

2.48

2.5

2.52

Output internal resistance of Uref

RI ref

Ω

120

200

333

−40 ° C... +125 °C

Electrical offset voltage

UO E

mV

−10

10

Uout − Uref

Lifetime offset drift

UO E LmV

Remanent field/Magnetic offset

UO M

mV

−9

9

After ±BM, on FS

Temperature coefficient of Uref

TCUref

ppm/K

−150

150

−40 ° C ... +125 °C;
referred to 35 °C

Temperature coefficient of UO E

TCUO E

mV/K

−0.1

0.1

−40 ° C... +125 °C;
referred to 35 °C

Output internal resistance of Uout

Rout

Ω

5

DC

Noise voltage spectral density

UnoµV/Hz 1/2

Delay time to 10 % of the final output
value for BN step

tD 10

µs

1.6

Input signal rise time 2 µs

Delay time to 90 % of the final output
value for BN step

tD 90

µs

1.4

Input signal rise time 2 µs

Frequency bandwidth

BW

kHz

±3.3

Conditions

UC > 4.6 V
Uref + UO E + (SN × B)
−40 °C ... 125 C

600
±0.5

1
200

−40 °C ... 125 °C,
referred to 35 °C

±1.5

±15

Uout − Uref

17

160

@ −3 dB100@ −1 dB

Definition of typical, minimum and maximum values
Unless otherwise stated (e.g. “100 % tested”), the LEM definition “min” and “max” is that the probability for values of samples to lie
in this interval is 99.73 %. For a normal (Gaussian) distribution, this corresponds to an interval between −3 sigma and +3 sigma.
The definition of “typical” is that the probability for values of samples to lie in this interval is 68.27 %, corresponding to an interval
between −sigma and +sigma for a normal distribution.
Typical, maximal and minimal values are determined during the initial characterization of the product.

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FHS AH 600
Overcurrent detection (OCD)
Overcurrent detection is a feature included on FHS AH product in order to detect high peaks of currents happening during
operation.
Two overcurrent detection types are included in this product: Internal OCD and External OCD.
At TA = 35 °C, UC = +5 V, RL = 100 kΩ unless otherwise noted.

Parameter

Symbol

Unit

Min

Typ

Max

Comment

INTERNAL OCD
Internal OCD detection threshold

BI OCD Th

mT

4.8

Internal OCD threshold error

εI OCD Th%−10Internal OCD output on resistance

Ron I OCDΩ70

Internal OCD output hold time

thold I OCDµs

7

Internal OCD delay time

tD I OCDµs

1.31.45 × BM, −40 ° C... +125 °C
10Referred to B @Uout − Uref = 0.8 V

95

150

Open drain output, active low

10

14
2.1

EXTERNAL OCD
Calculated from external
resistors - see formula below

External OCD detection threshold

BE OCD Th

T

External OCD threshold error

εE OCD Th%−5External OCD output on resistance

Ron E OCDΩ

35

External OCD output hold time

thold E OCDµs

10External OCD delay time

tD E OCD

µs

10

200

5

Referred to
B @ Uout − Uref = 0.8 V

280Open drain output, active low

Setting External OCD threshold:
The external Over-Current-Detection threshold is directly set by user with the external resistors RE and RE ref using the following
formula:U E OCD=RE⋅ U ref
RE + RE ref

The corresponding sensed magnetic field threshold is defined by the external voltage threshold and device sensitivity using thefollowing formula:=
BE OCDU ref − UE OCD
with 0.5 < UE OCD < U ref − 0.5
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FHS AH 600
Terms and definitions
Sensitivity and linearity
To measure sensitivity and linearity, the primary current (DC) is cycled from 0 to BM, then to −BM and back to 0
(equally spaced BM /10 steps).
The sensitivity S is defined as the slope of the linear regression line for a cycle between ±BM.
The linearity error εL is the maximum positive or negative difference between the measured points and the linear regression line,
expressed in % of BM.

Thermal coefficient of Sensitivity

Thermal coefficient of Uref
U
− U ref at RT 
1=
× 106 ppm/K
TCU ref (T )  ref at T
×
U
T
−
RT )
(
ref at RT

RT: Room Temperature
T: temperature which TCS is calculated.

Delay times
The delay time tD 10 @ 10 % and the delay time tD 90 @ 90 % with respect to the primary are shown in the next figure.
They are measured at nominal cuurent with a current rise time of 2 µs.
I
100 %
90 %

IS

IP
tD 90
10 %

tD 10

t

Figure 3: Delay time tD 10 @ 10 % and delay time tD 90 @ 90 %Page 6/17
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FHS AH 600
Internal OCD behavior
0
5

10

15

20

25

30

35

40

45

Ip current remains higher than OCD threshold levelIp(A)Internal OCD Threshold level
OCD delay
time

Internal OCD output hold time: min 10 µs (TYP), no max duration

OCD_INTIp current stays close to OCD threshold levelIp(A)Internal OCD Threshold level
OCD delay
time

Internal OCD output hold time is not always respected

OCD_INT

Short Ip current peak
Ip(A)Internal OCD Threshold levelPeak< 1.3 µs

OCD response
timeInternal OCD output hold time:min 10 µs (TYP), no max duration

No OCD activation if current peak < 1.3 µs

OCD_INT

Figure 4: Internal OCD behaviour

External OCD behavior
0
5

10

15

20

25

30

35

40

45

Ip current remains higher than external OCD threshold level
OCD_EXT delay time:
10 µs + reaction time

OCD_EXT delay time:
10 µs + reaction time

Ip(A)External OCD Threshold level
Set with voltage on VOCExternal OCD output hold time:
10 µs (TYP), no max duration

OCD_EXT

Ip current stays close to OCD threshold level (noisy up & down signal)
OCD_EXT delay time:
10 µs + reaction time

Ip(A)OCD_EXT delay time:
10 µs + reaction time

External OCD Threshold level
Set with voltage on VOCExternal OCD output hold time:
10 µs (TYP), no max duration

OCD_EXT

Short Ip current peak
Ip(A)

Peak
< 10 µs

OCD_EXT delay time:
10 µs + reaction time

OCD_EXT delay time:
10 µs + reaction time
External OCD Threshold level
Set with voltage on VOCExternal OCD output hold time:
10 µs (TYP), no max duration

OCD_EXTNo OCD activation if current peak < 10 µs

Figure 5: External OCD behaviour
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FHS AH 600
Accuracy

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FHS AH 600

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FHS AH 600
Frequency response

Phase (°)

uno (V RMS /Hz (1/2))

Noise			Figure 6: Noise voltage spectral density		

Figure 7: Gain and phase over frequency

Linearity

Figures 8, 9: Linearity error @ 35 °C and @ 125 °C

di/dt

Figure 10: delay time to current step (di/dt)

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FHS AH 600
Application information
Basic operation: example with a long thin conductor
FHS AH is a galvanically insulated current transducer.
It senses the magnetic field generated by the measured current and transforms it into an output voltage.
If the current is bidirectional, FHS AH will sense the polarity of the magnetic field and generate a positive or negative output voltage
relative to the reference voltage.
A simple case is presented which illustrates the current to magnetic field and then to output voltage conversion.
A current flowing in a long thin conductor generates a flux density around it:With:
IP the current to be measured (A)r the distance from the center of the wire (m)μ0 the permeability of vacuum (physical constant, μ0 = 4.π. 10-7 (H/m)

Figure 11: FHS AH orientation to measure the magnetic field generated by a current along a conductor
If FHS AH is now placed in the vicinity of the conductor (with its sensitivity direction colinear to the flux density B),
it will sense the flux density and the output voltage will be:where SN is the FHS AH sensitivity (600 V/T).
The transducer sensitivity to current is therefore:S=

U out 1.2 ⋅ 10−4
V/A
=
IP
r

The next graph shows how the output voltage decreases when r increases.
Note: that the sensitivity also depends on the primary conductor shape.

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FHS AH 600
Sensitivity function of distance(thin and long conductor)

Sensitivity (mV/A)

250
200
150
100
50
0
0

1

2

3

4

Conductor to sensor distance (mm)Figure 12: Sensitivity versus the distance between the conductor and the FHS AH sensing elements
The example above is of limited practical use as most conductors are not round and thin but explains the principles of FHS AH
operation.
The measuring range limit (IP M) is reached when the output voltage (Uout − Uref) reaches 2 V.
This limit is due to electrical saturation of the output amplifier.
The input current or field may be increased above this limit without risk for the circuit.
Recovery will occur without additional delay (same delay time as usual).
The maximum current that can be continuously applied to the sensor (IP M) is only limited by the primary conductor carrying
capacity.
Single track on PCB
The main practical configuration for FHS AH is to measure current flowing directly through a PCB track (single or multi-layers),
offering the following advantages:● Insulation is guaranteed by PCB design. Very high insulation can be achieved by placing the primary (current carrying) trackon the opposite side of the PCB.
● Cost effective solution● Wide input current range (up to 100 A)● Compact solution● No added power losses● No change on current track impedance

1

Ip

B
PCB

B

B
PCB

PCB

Primary Conductor (Track)
Primary Conductor(Track)Figure 13: Principle of FHS AH used to measure current in a PCB track
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FHS AH 600

Figure 14: Sensitivity versus track width and versus distance between the track and the FHS AH sensing elements (TBC).
The sensitivity depends on the track width and distance, as shown in above figure.
The maximum current that can be safely applied continuously is determined by the temperature rise of the track.
The use of a track with varying width gives the best combination of sensitivity and track temperature rise.
Multi-turns
For low currents (under 10 A), it is advisable to make several turns with the primary track to increase the magnetic field generated
by the primary current.
BusbarFor very large currents (> 50 A), FHS AH can be used to measure the current flowing in a busbar.
The position of FHS AH relatively to the conductor has to be stable to avoid sensitivity variations.

B

PCB

Ip

BusbarFigure 15: Example with busbar
Accuracy considerations
Several factors influence the output accuracy of FHS AH as a current sensor:● The sensitivity of the FHS AH● The distance and shape of the primary conductor● The circuit output offset● The circuit non-linearity● Stray fields.
The sensitivity of the FHS AH is calibrated during production at 600 V/T.
As mentioned above, the distance and shape of the primary conductor also influence the sensitivity.
For best performance, no relative mouvement of the primary conductor to FHS AH should be possible.
Mechanical tolerances on device position and primary conductor design can have an impact on performance and part-to-partdeviation and should therefore be minimized.
The magnetic fields generated by neighboring conductors, the earth’s magnetic field, magnets, etc. are also measured if they havea component in the direction to which FHS AH is sensitive.
As a rule, the stronger the field generated by the primary current, the smaller the influence of stray fields and offset.
The primary conductor should therefore be designed to maximize the output voltage.
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FHS AH 600
PCB footprint & dimensions (in mm)

Notes:All dimensions are in millimeters (angles in degrees)* Dimensions do not include mold flash, protrusions or gate burrs (shall not exceed 0.15 per side)** Dimension does not include interleads flash or protrusion (shall not exceed 0.25 per side)*** Dimension does not include dambar protrusion.
Allowable dambar protrusion shall be 0.08 mm total in excess of the dimension at maximum material condition.
Dambar cannot be located on the lower radius of the foot.
Soldering:
Recommended reflow soldering profile as standard: IPC/JEDEC J-STD-020 revision C.

Typical connection diagram and ground plane
Good EMC practice requires the use of ground planes on PCBs. In drives where high dv/dt transients are present, a ground plane
between the primary conductor and FHS AH will reduce or avoid output perturbations due to capacitive currents. However, theground plane has to be designed to limit eddy currents that would otherwise slow down the delay time.
The effect of eddy currents is made negligible by cutting the copper plane under the package as shown in bellow figure.

cut in the plane
under the circuit

Figure 16: Top side copper plane has a cut under the IC to optimize delay time
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FHS AH 600
Tape & Reel

Tape on Reel Specification SOIC8 150 mil
Live Bug Taping (standard)

Packing
Pin 1

Carrier Tape

Cover Tape

Label

Dead Bug Taping (optional)
Pin 1

Carrier Tape

Cover Tape

Plastic Reel 13’’
Remark:Pay attention to the marking orientation because it is used for component(pin1) orientation. Some devices may have different marking orientation.
Plastic 13’’ Reel:
Made by antistatic high-impact molded polystyrene. The mechanicalintegrity of the reel is not affected by humidity.

*Dry-Pack
Label Sample
Moisture Barrier Bag (MBB):
Made in 5 different layers with total thickness of 0.18 mm.
At the core is a layer of polyester sandwiched between aluminum
shields. The outside layer: dissipative polyester, innermost layer:
static dissipative polyethylene.

.

Specifications subject change without notice2016 Melexis Semiconductors*Label images are for illustration purpose only. They could differ depends on MSL level.

-1-

July 2016/Rev. 006

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Leader and Trailer

Carton Box A

Carton Box B**

Carton Box A

Carton Box B**

Carton Box A

Carton Box B**

Box Size (mm)460 x 420 x 320

460 x 420 x 230

450 x 420 x 260

450 x 420 x 160

450 x 400 x 300

450 x 400 x 200

QTY/Reel

3000pcs

3000pcs

3000pcs

3000pcs

3000pcs

3000pcs

Reel Size

13’’

13’’

13’’

13’’

13’’

13’’

Reels/Box

14pcs

10pcs

11pcs

6pcs

15pcs

10pcs

QTY/Box

42 000pcs

30 000pcs

33 000pcs

18 000pcs

45 000pcs

30 000pcs

Weight/Box
12
9
9
5
15
10
(kg)
* The packing type depends on product. For more information ask your Melexis contact person.
** Carton box B is used as last box in shipment, or when the shipping reel quantity is lower, or equal than 6 /10 reels (depending on the packing type).

FHS AH 600

Leader and Trailer

Components
Trailer Tape
400 mm50 empty pockets

Carrier
Tape
Data
Carrier
Tape
Data.
2016 Melexis Semiconductors

User direction of feed

Leader Tape
1000 mm
125 empty pockets

Specifications subject change without notice

Carrier Tape Data

-2-

July 2016/Rev. 006

Carrier Tape Data

Component
Rotation
andandLateralMovement
Component
Rotation
LateralMovement

Component
Rotation andLateral Movement
Component
Rotationand Lateral Movement

Plastic Reel Data
Plastic Reel Data

Plastic
Reel
Data
Plastic
Reel
Data

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Specifications subject change without notice2016 Melexis Semiconductors-3-

July 2016/Rev. 006

FHS AH 600
Safety⚠

CautionIf the device is used in a way that is not specified by the manufacturer, the protection provided by the device may be compromised.
Always inspect the electronics unit and connecting cable before using this product and do not use it if damaged.
Mounting assembly shall guarantee the maximum primary conductor temperature, fulfill clearance and creepage distance,
minimize electric and magnetic coupling, and unless otherwise specified can be mounted in any orientation.

Caution, risk of electrical shock
This transducer must be used in limited-energy secondary circuits SELV according to IEC 61010-1, in electric/electronic equipmentwith respect to applicable standards and safety requirements in accordance with the manufacturer’s operating specifications.
Use caution during installation and use of this product; certain parts of the module can carry hazardous voltages and high currents(e.g., power supply, primary conductor).
Ignoring this warning can lead to injury and or/or cause serious damage.
De-energize all circuits and hazardous live parts before installing the product.
All installations, maintenance, servicing operations and use must be carried out by trained and qualified personnel practicing
applicable safety precautions.
This transducer is a build-in device, whose hazardous live parts must be inaccessible after installation.
This transducer must be mounted in a suitable end-enclosure.
Besides make sure to have minimum 30 mm between the primary terminals of the transducer and other neighboring components.
Main supply must be able to be disconnected.
Always inspect the flexible probe for damage before using this product.
Never connect or disconnect the external power supply while the primary circuit is connected to live parts.
Never connect the output to any equipment with a common mode voltage to earth greater than 30 V.
Always wear protective clothing and gloves if hazardous live parts are present in the installation where the measurement is carriedout.
This transducer is a built-in device, not intended to be cleaned with any product. Nevertheless, if the user must implement cleaning
or washing process, validation of the cleaning program has to be done by himself.
When defining soldering process, please use no cleaning process only.

ESD susceptibility
The product is susceptible to be damaged from an ESD event and the personnel should be grounded when handling it.
Do not dispose of this product as unsorted municipal waste. Contact a qualified recycler for disposal.
Although LEM applies utmost care to facilitate compliance of end products with applicable regulations during LEM productdesign, use of this part may need additional measures on the application side for compliance with regulations regarding EMC andprotection against electric shock.
Therefore, LEM cannot be held liable for any potential hazards, damages, injuries or loss of life resulting from the use of thisproduct.

Version history
Date
8 June 2023

Version0

Comments
New datasheet

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