VG484 FMSH 6–28V Analog IC DIP16

The FMSH VG484 is an analog ic. The FM484 is an integrated circuit designed for use with an NPN darlington in breakerless ignition systems with magnetic pickup sensors and high energy ignition coils. For the special design which has two input pins from the pickup, it can be used with a wide variety of magnetic sensors. The device drives an NPN external darlington to control the coil current providing the required stored energy with low dissipation. This circuit has many advantages: low power dissipation, stable, high ignition energy, self-protection, widely application conditions, long using life, etc. It’s compatible for overseas products of the same class.

Key Specifications

Features

• ‹ Direct driving of the external darlingto
• ‹ Operates with a wide range of magnetic pickup types
• ‹ Charging angle (dwell) contro
• ‹ Coil current peak limitatio
• ‹ Continuous coil current protectio
• ‹ Tachometer signal output
• ‹ External darlington overvoltage protectio
• ‹ Load dump and reverse battery protectio

Design Notes

• The trip threshold is specified over a tolerance band, not at a single point. Design the sense resistor against the worst-case ends of that band, or nuisance tripping will appear at temperature extremes.
• These circuits are usually supplied from a capacitive dropper or a resistive divider off the mains. Verify the supply current budget against the datasheet before adding load.
• Package choice drives creepage. For mains-referenced parts, use the widest package the layout allows and keep the specified clearance to the low-voltage side.
• Check the temperature coefficient of the threshold if the product must hold accuracy over an outdoor temperature range.

Common Questions

What is the trip threshold?

the threshold above. The threshold is specified over a tolerance band, so size the sense element against the band ends rather than the typical value.

What does this device do?

Magnetic pickup ignition controller. It integrates the control loop that would otherwise need a board of discrete parts.

Which packages are offered?

DIP16. For mains-referenced circuits choose the package that meets the creepage requirement of the layout.

How is it powered?

Typically from a capacitive dropper or resistive divider off the mains rail. Check the supply current budget in the datasheet before adding any load to that rail.