il3522 NVE Corp., il3522 Datasheet - Page 6

• Manufacturer Part Number: il3522
• Description: Isolated Rs485/rs422 Interface
• Manufacturer: NVE Corp.

Electrostatic Discharge Sensitivity
This product has been tested for electrostatic sensitivity to the limits stated in the specifications. However, NVE recommends that all integrated
circuits be handled with appropriate care to avoid damage. Damage caused by inappropriate handling or storage could range from performance
degradation to complete failure.
Power Consumption
IsoLoop Isolators achieve their low power consumption from the way they transmit data across the isolation barrier. By detecting the edge
transitions of the input logic signal and converting these to narrow current pulses, a magnetic field is created around the GMR Wheatstone
bridge. Depending on the direction of the magnetic field, the bridge causes the output comparator to switch following the input logic signal.
Since the current pulses are narrow, about 2.5 ns, the power consumption is independent of mark-to-space ratio and solely dependent on
frequency. This has obvious advantages over optocouplers, which have power consumption heavily dependent on frequency and time.
Power Supply Decoupling
Both V
operation. Additionally, V
DC Correctness
The IL3585 incorporates a patented refresh circuit to maintain the correct output state with respect to data input. At power up, the bus outputs
will follow the Function Table shown on Page 1. The DE input should be held low during power-up to eliminate false drive data pulses from the
bus. An external power supply monitor to minimize glitches caused by slow power-up and power-down transients is not required.
Electromagnetic Compatibility
The IL3522 is fully compliant with generic EMC standards EN50081, EN50082-1 and the umbrella line-voltage standard for Information
Technology Equipment (ITE) EN61000. The IsoLoop Isolator’s Wheatstone bridge configuration and differential magnetic field signaling
ensure excellent EMC performance against all relevant standards. NVE conducted compliance tests in the categories below:
EN50081-1
EN50082-2: Industrial Environment
ENV50204
Immunity to external magnetic fields is even higher if the field direction is “end-to-end” (rather than to “pin-to-pin”) as shown in
the diagram at right.
Application Information
Receiver Features
The receiver includes a “fail-safe if open” function that guarantees a high level output if the receiver inputs are unconnected (floating). The
receiver output “R” has tri-state capability via the active low RE input.
Driver Features
The RS-422 driver is differential output and delivers at least 1.5 V across a 54 Ω load. Drivers feature low propagation delay skew to maximize
bit width and minimize EMI. Drivers have tri-state capability via the active-high DE input.
Receiver Data Rate, Cables and Terminations
The IL3522 is intended for networks up to 4,000 feet (1,200 m), but the maximum data rate decreases as cable length increases. Twisted pair
cable should be used in all networks since they tend to pick up noise and other electromagnetically induced voltages as common mode signals,
which are effectively rejected by the differential receivers.
Residential, Commercial & Light Industrial
Methods EN55022, EN55014
Methods EN61000-4-2 (ESD), EN61000-4-3 (Electromagnetic Field Immunity), EN61000-4-4 (Electrical Transient Immunity),
EN61000-4-6 (RFI Immunity), EN61000-4-8 (Power Frequency Magnetic Field Immunity), EN61000-4-9 (Pulsed Magnetic
Field), EN61000-4-10 (Damped Oscillatory Magnetic Field)
Radiated Field from Digital Telephones (Immunity Test)
NVE Corporation
DD1
and V
DD2
must be bypassed with 47 nF ceramic capacitors. These should be placed as close as possible to V
11409 Valley View Road
DD2
should be bypassed with a 10 µF tantalum capacitor.
Data Rate (Mbps)
Eden Prairie, MN 55344-3617 USA
10
20
40
1
Table 2. Typical Dynamic Supply Currents.
100 μA
1 mA
2 mA
4 mA
I
DD1
6
Telephone: [phone]
100 μA
1 mA
2 mA
4 mA
I
DD2
Fax [phone]
Internet: www.isoloop.com
DD
IL3522
pins for proper