AAV003-10E

Data Sheet AAV003-10E Current Sensor Key Features • For Low Current Detection • On-Chip Current Strap for Precise Operation • −80 mA to +80 mA Linear Range • Sensitivity up to 2 mV/mA • AC or DC Measurement • Ultraminiature TDFN Package Description The AAV003-10E is a high linearity, extremely low hysteresis GMR current sensor with an on-chip current strap. A GMR bridge sensor element close to the current strap senses the magnetic field created by the current. The GMR sensor element uses a unique, bipolar output, low hysteresis GMR material for excellent accuracy. The four terminals of the bridge sensor are available externally. The output terminals of the bridge provide a bipolar voltage signal proportional to the current through the strap. V+ (Pin 1) GMR Bridge V- Out+ Out- AAV003-10E I+ I- AAV003-10E Functional Diagram NVE Corporation • 11409 Valley View Road, Eden Prairie, MN 55344-3617 • (952) 829-9217 • www.nve.com AAV003-10E Current Sensor Operation A representative transfer curve is shown below: A AV003-10E B ridg e O utput vs Input C urrent 5V S upply Voltag e, 25C 0.175 0.15 0.125 0.1 0.075 0.05 B ridg e Output (V) 0.025 0 -0.025 -0.05 -0.075 -0.1 -0.125 -0.15 ‐0.175 -0.6000 -0.5000 -0.4000 -0.3000 -0.2000 -0.1000 0.0000 0.1000 0.2000 0.3000 0.4000 0.5000 0.6000 Input C urrent (A) Operating Specifications: Parameter Nominal Bridge Resistance Sensitivity Frequency Response Linear Range of Current Measurement Output Linearity Bridge Electrical Offset Offset Drift over Full Temperature Range Bridge Supply Voltage Isolation Voltage On-Chip Current Strap Resistance On-Chip Current Strap Resistance Temperature Coefficient Temperature Range of Operation Bridge Resistance Temperature Coeff. Bridge TCOV2 Test Conditions 25°C Operating; 5 V Supply, 25°C Operating; Full Voltage and Temperature Range Over Linear Current Range; Full Oper. Temperature Range 25°C Zero Current See Note 1 25°C Min. 5500 0.06 100 −80 99% −4 −1.0 240 0.25 +0.6 Operating Operating Operating −40 +0.1 −0.21 85 +4 1.0 24 0.35 mV/V mV/V |Volts| VRMS Typ. 7000 0.08 Max. 8500 0.10 80 Units Ohms mV/V-mA KHz mA Ohms %/°C °C %/°C %/°C Notes: 1. For isolation measurement, the sensor is considered a two terminal device: I+ and I- pins (pins 3 and 4) are shorted, and bridge pins (pins 1, 2, 5, and 6) are shorted. 2. TCOV is the percent change in output signal over temperature, with a constant voltage source powering the part. Absolute Maximum Ratings: Parameter Absolute Maximum Current Bridge Supply Voltage Storage Temperature Ambient Magnetic Field Min. −600 −40 Typ. Max. 600 30 170 Unlimited Units mA Volts °C Note: Exceeding Absolute Maximum Ratings may cause permanent damage. NVE Corporation • 11409 Valley View Road, Eden Prairie, MN 55344-3617 • (952) 829-9217 • www.nve.com AAV003-10E Current Sensor External Magnetic Fields and Hysteresis Effects The AAV003-10E sensor elements are shielded to make them insensitive to external magnetic fields, however, shielding is not 100% effective, so external fields applied to the sensor should be avoided for the most repeatable, accurate operation. When exposed to magnetic fields over 50 Oe (5 mT), the characteristic of the sensor can be disturbed, causing a hysteresis effect that will produce a non-linear response. A magnetic field of 50 Oe is a large field that should not be encountered during normal operation. However, in case the sensor is exposed to such a field, a degauss pulse train can be applied to the sensor to restore the original response. The sensor cannot be permanently damaged by any magnetic field, no matter how large and it can always be restored after exposure to a large field with a degauss signal. This same effect can be observed when a large constant current (>200 mA) is applied to the on-chip current strap, or a smaller constant current (>100 mA) at high temperatures (>85°C). Again in these cases, correct operation of the sensor is restored with a degauss signal. The degauss signal should consist of at least four current pulses of alternating polarity, with a pulse width of at least 50 µs and an initial current pulse of 600 mA: Typical Degauss Pulse 900 750 600 450 Minimum Duration at Peak 50 μs Current (mA) 300 150 0 -150 -300 -450 -600 Time (μs) 100 200 300 400 500 Temperature Characteristics Typical output over temperature is shown in the graph below: A AV003-10E O utput over Temperature - Typic al 0.200 0.150 0.100 0.050 O utput S ig nal (V) 0.000 -0.050 -0.100 -0.150 -0.200 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 O n-C hip S trap C urrent (A) -50 -20 25 C 85 C 125 C NVE Corporation • 11409 Valley View Road, Eden Prairie, MN 55344-3617 • (952) 829-9217 • www.nve.com AAV003-10E Current Sensor Pinout The AAV003-10E pinout is as follows: Pin 1 2 3 4 5 6 Terminal V+ Out+ I+ I− Out− V− Description Supply Voltage Positive Differential Bridge Output Current Terminal 1 Current Terminal 2 Negative Differential Bridge Output Ground Notes: 1. Pins are numbered counterclockwise around the package. 2. Current entering the chip via terminal I+ and leaving the chip via terminal I− produces a positive bridge output. Package Drawing – TDFN6 2.5 mm x 2.5 mm Notes: • • • • Dimensions in mm. TDFN6 package has thermal power dissipation of 320°C/Watt in free air. Attaching the package to a circuit board improves thermal performance, especially if the center pad is also soldered to the board. The center pad may be left floating or connected to ground. SB-00-022; Jan. 26, 2009 NVE Corporation • 11409 Valley View Road, Eden Prairie, MN 55344-3617 • (952) 829-9217 • www.nve.com