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Isolators Named to Hot 100 
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| Award-winning IL500 digital isolators |
| pack in as many as four channels |
| and operate as fast as 2 Mbps. |
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NVE's new IL500-Series digital isolators have been named a Hot 100 Product of 2008 in the latest issue of EDN.
According to EDN, the prestigious annual listing is compiled by its editors and highlights the electronics industry's most innovative and significant products.
Designed to be cost-effective optocoupler replacements, IL500-Series isolators operate at two megabits per second, offer a dc-correct design, and have an external synchronization option on certain models.
Key specifications are:
• 2 Mbps; 10 ns PWD
• DC Correct
• External Clock Option (IL510; IL515)
• Output Enable (IL510; IL514; IL515)
• 1, 2, 3, or 4 Channels
• -40°C to 85°C Temp. Range
• 2.5 kVrms Isolation (1 min.)
• UL1577 and IEC 61010-2001 Approved
• MSOP and SOIC Packages
<More About Award-Winning IL500 Isolators>
Current Sensor
The new AAV003-10E
is a highly linear, extremely low hysteresis GMR current sensor with an on-chip current strap. A GMR bridge sensor element close to the strap senses the current. The output of the bridge voltage is bipolar and proportional to the current through the strap over a -80 to +80 mA input range.
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AAV003-10E Current Sensor
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Typical sensitivity is a remarkable 1 mV/V with a 12 V supply and no amplification.
The parts come in an ultraminiature 2.5 mm by 2.5 mm 6-pin TDFN package.
AAV003-10E current sensors are targeted at circuit board current sensing for process control and instrumentation. Their sensitivity makes them ideal for 4-20 mA current loop detection.
<More About NVE's New Current Sensors>
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| Application Corner |
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Noncontact Current Measurement
Using Analog Sensors
By
Jay Brown
Vice President, Sensors
In addition to the new AAV003-10E covered above, AA-
or AAH-Series GMR magnetometers can determine ac or dc current by measuring the magnetic field from a circuit board trace without a direct connection. This method can be used to measure large currents, and the accuracy is generally adequate for
overcurrent protection.
The axis of magnetic
sensitivity is along the package, so the configuration
shown below is often used, with the current-carrying
trace on the opposite side of circuit board from the
sensor:
The magnetic field at the sensor element is approximated as:
Where I is the current in conductor, r is the distance of the sensor from the center of the conductor, and H is the magnetic field at the sensor element in A/m using SI units (1 A/m = 0.0126 Oe in air).
For example, with a SOIC-packaged sensor on a 1.6 mm thick PCB with 3 oz plated copper, r = 2.94 mm. If D1 = D2 = 10 mm, the critical field strength at the sensor for a 10 A overcurrent
would be 519 A/m or 6.54 Oe. A circuit can easily be designed with an AA002-2 sensor and a comparator to switch at 6.54 Oe or 10 A.
For more information on current measurement designs, including a detailed circuit for this example, see Application Bulletin No.
SA-1 (.pdf). You can also download the recently updated Current Field Calculator (.xls).
<More Sensor Applications>
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| Sensor Part Numbering |
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NVE sensor part numbers have five alphanumeric fields as summarized below:
AA H
004 - 00
E
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Base Part
AA = Analog output magnetometer
AB = Analog output gradiometer
AD = Digital switch
AF = Low-voltage digital switch
AG = Evaluation kit or PCB
AK = Digital output gradiometer
BA = Custom analog sensor
BD = Custom digital sensor
DB = Digital signal processing IC
DC = Voltage regulator
DD = Analog signal processing IC
GMR Material
Blank = Standard material
H = High-sensitivity, high-temp. multilayer
L = Low hysteresis, high-temp. multilayer
V = Spin-valve material |
Part Subtype
(meaning depends on Base Part)
Package Type
00 = MSOP8
01 = Bare die
02 = SOIC8
07 = Non-IC such as eval. kit or PCB
10 = 2.5 mm x 2.5 mm TDFN6
11 = 3 mm x 3 mm PLLP6
12 = 4.9 mm x 6.0 mm TDFN SO8
Part Package
Blank = Lead (Pb)
E = RoHS |
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An NVE distributor since 2001, Digi-Key has earned top industry ratings including #1 in availability of product and #1 in on-time delivery.
