IL711/IL712/IL721

11

NVE Corporation

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

(952) 829-9217

www.nve.com

YouTube.com/NveCorporation

iso-apps@nve.com

80 ns

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 IEC 61000-6-1 and

IEC 61000-6-2 standards for immunity, and IEC 61000-6-3,

IEC 61000-6-4, CISPR, and FCC Class A standards for emissions.

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.

Power Supply Decoupling

Both power supplies should be decoupled with 0.1 µF typical

(0.047 µF minimum) capacitors as close as possible to the VDD

pins. Ground planes for both GND1 and GND2 are highly

recommended for data rates above 10 Mbps.

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. Package drawings

and recommended pad layouts 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 IL712 or IL721 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.

Data Transmission Rates

The reliability of a transmission system is directly related to the

accuracy and quality of the transmitted digital information. For a digital

system, those parameters which determine the limits of the data

transmission are pulse width distortion and propagation delay skew.

Propagation delay is the time taken for the signal to travel through

the device. This is usually different when sending a low-to-high

than when sending a high-to-low signal. This difference, or error, is

called pulse width distortion (PWD) and is usually in nanoseconds.

It may also be expressed as a percentage:

PWD% = Maximum Pulse Width Distortion (ns)

x 100%

Signal Pulse Width (ns)

For example, with data rates of 12.5 Mbps:

PWD% = 3 ns

x 100% = 3.75%

This figure is almost three times better than any available

optocoupler with the same temperature range, and two times better

than any optocoupler regardless of published temperature range.

IsoLoop isolators exceed the 10% maximum PWD recommended

by PROFIBUS, and will run to nearly 35 Mb within the 10% limit.

Propagation delay skew is the signal propagation difference between two

or more channels. This becomes significant in clocked systems because it

is undesirable for the clock pulse to arrive before the data has settled.

Propagation delay skew is especially critical in high data rate parallel

systems for establishing and maintaining accuracy and repeatability.

Worst-case channel-to-channel skew in an IL700 Isolator is just 3 ns—

ten times better than any optocoupler. IL700 Isolators have a maximum

propagation delay skew of 6 ns— five times better than any optocoupler.