V-Series Isolators

10

NVE Corporation

11409 Valley View Road, Eden Prairie, MN 55344-3617

Phone: (952) 829-9217

Fax: (952) 829-9189

www.IsoLoop.com

©NVE Corporation

Application Information

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.

Electromagnetic Compatibility

IsoLoop Isolators have the lowest EMC footprint of any isolation

technology. IsoLoop Isolators’ Wheatstone bridge configuration

and differential magnetic field signaling ensure excellent EMC

performance against all relevant standards.

These isolators are fully compliant with generic EMC standards

EN50081, EN50082-1 and the umbrella line-voltage standard for

Information Technology Equipment (ITE) EN61000. NVE has

completed compliance tests in the categories below:

EN50081-1

Residential, Commercial & Light Industrial

Methods EN55022, EN55014

EN50082-2: Industrial Environment

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)

ENV50204

Radiated Field from Digital Telephones (Immunity Test)

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 below:

Cross-axis Field Direction

Dynamic 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 mark-to-space ratio.

Thermal Management

IsoLoop Isolators are designed for low power dissipation and

thermal performance, providing unmatched channel density for

high-performance isolators. Nevertheless, package temperature rise

should be considered when running multiple channels at high

speed. Power consumption is higher at 5 volt operation than at

3.3 volts, and dynamic supply current is higher on the input side of

the isolators than the output side, so thermal management is more

important with five-volt input-side power supplies.

Based on the specifications contained in this datasheet, the derating

curve at typical operating conditions is as follows:

Power Supply Decoupling

Both power supplies to these devices should be decoupled with

low-ESR 47 nF ceramic capacitors. Ground planes for both GND1

and GND2 are highly recommended for data rates above 10 Mbps.

Capacitors must be located as close as possible to the VDD pins.

Maintaining Creepage

Creepage distances are often critical in isolated circuits. In addition

to meeting JEDEC standards, NVE isolator packages have unique

creepage specifications. Standard pad libraries often extend under

the package, compromising creepage and clearance. Similarly,

ground planes, if used, should be spaced to avoid compromising

clearance. The package drawing and recommended pad layout are

included in this datasheet.

Signal Status on Start-up and Shut Down

To minimize power dissipation, input signals are differentiated and

then latched on the output side of the isolation barrier to reconstruct

the signal. This could result in an ambiguous output state depending

on power up, shutdown and power loss sequencing. Unless the circuit

connected to the isolator performs its own power- on reset (POR), a

start-up initialization circuit should be considered. Initialization

consists of toggling the input either high then low, or low then high.

In CAN applications, the IL721V should be used with CAN

transceivers with Dominant Timeout functions for seamless POR.

Most CAN transceivers have Dominant Timeout options. Examples

include NXP’s TJA 1050 and TJA 1040 transceivers