DIGITAL HALL-EFFECT SENSORS

VHEDCS-XX

Vertical Hall-Effect Digital Current Sensors

- Output voltage is isolated from the input
- Open Collector 25mA Output
- Senses DC or AC current
- Excellent temperature stability
- Operation -40 to +125°C
- Operates with an unregulated Supply of 4.5 to 24Vdc

DESIGN NOTES

The current sensors described in this brochure are manufactured of the highest quality raw materials utilizing gapped ferrite cores and digital hall effect sensors. These current sensors can sense either DC or AC current. When sensing zero current, the output voltage is equal to the supply voltage (Vcc). The output voltage remains equal to Vcc as long as the sensed current level is less than the "operate current" level (IOP). When the sensed current level is increased to above IOP the output voltage falls to approximately .2 volts. The output voltage remains at .2 volts until the sensed current is decreased to below the "release current" level (IREL). When the sensed current level is decreased to below IREL the output voltage rises to Vcc.

These current sensors are designed to provide accuracy and versatility for applications in automobile and transportation diagnostics, power supplies, motor controls, overload protection circuits, and energy management systems. They are provided as rectangular vertical standing units to minimize mounting space. They are designed for printed circuit board applications and incorporate standoff feet on the toroid carrier to allow solder fillet formation and flush cleaning of solder-flux residue from under the component after the soldering operation.

These current sensors are designed and manufactured in the smallest possible package sizes. The toroid and sensor are secured to the housing with epoxy resin. Leads are tin-plated per MIL-P-81728, semi-bright. Carriers are molded of a liquid crystal polymer (LCP) plastic exhibiting excellent mechanical strength and dimensional stability, high dielectric strength and a low coefficient of thermal expansion. Provided in an off-white color, the material can be used continuously at 280°C (536°F), has a melt point above 335°C (635°F), is inherently flame retardant and meets the flammability requirements of UL 94V-0.

These current sensors are designed for -40 to +125°C operation. Current sensors are capable of withstanding 500 V DC @ 50 microamps applied between the input coil leads and the output voltage lead.

The current to be sensed is applied to the sensor coil leads which are marked with a "+" and a "-" on the front of the case. A dot on the front of the case designates the output voltage lead. The two leads next to the output voltage lead are the common lead (next to the output voltage lead) and the supply voltage lead. The VHEDCS-46 does not have a sensor coil. A single wire passed through the center of the core provides a single turn coil with an "operate current" of approximately 46 amps and a "release current" of approximately 36 amps. Passing the wire through the center of the core a second time reduces the "operate current" to 23 amps and the "release current" to 18 amps, etc. The VHEDCS-46 is provided with two 8-32 mounting studs in place of the sensor coil leads.

Marking consists of manufacturer's logo (EC2), part number, terminal identification and date code of manufacture. All marking is applied by silk-screen process using blue epoxy paint in accordance with MIL-STD-130, to meet the permanency of identification required by MIL-STD-202, Method 215.

OPERATING SPECIFICATIONS

Supply Voltage (Vcc).............. 4.5 to 24 Vdc
Supply current.................... 4.4mA typ., 9mA max.
Maximum Output Current............ 25mA
Vout (on)......................... .2 Vdc typ.
Vout (off)........................ Vcc
Rise Time Out(R=820 ohms/C=20 pf). .04us typ.
Fall Time Out(R=820 ohms/C=20 pf). .18us typ.
                      

PART NUMBER TABLE

Special modules can be manufactured to provide customer specified trip currents.