MX8681R IXYS, MX8681R Datasheet - Page 7

• Manufacturer Part Number: MX8681R
• Description: IC FLUX SENSOR 12BIT DGTL 8-DFN
• Manufacturer: IXYS
• Type: Unipolar Switchr

Specifications of MX8681R

• Voltage - Supply: 4.5 V ~ 5.5 V
• Current - Supply: 3mA
• Output Type: Digital, 12-Bit Serial
• Features: High Sensitivity
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-VFDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensing Range: -
• Current - Output (max): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MX8681
Application Example
This application example illustrates one method of incorporating the MX8681 into a power circuit board
design. The double-sided 8oz copper traces carry 20A (10 A on the top trace and 10A on the bottom
trace) around the center section of the planar E-core. The MX8681 is mounted on a small single layer
flex circuit that effectively adds a third layer. The flex also fans out the fine pitch DFN package to a pitch
compatible with the power board. The magnetic circuit consists of two ferrite E14 planar cores. The
center post of one of the cores is gapped to accommodate the MX8681 package thickness plus the flex
circuit thickness. For the 20A full scale application a gap of 47 to 52 mils is appropriate (1.2 to 1.32 mm).
The gain trim range of the MX8681 can accommodate even larger gaps if required.
This following example illustrates the MX8681 mounted directly on a 1oz PCB with a copper strap
positioned around the Hall element to carry the current being measured.
Design alternatives:
The use of an E-I core pair results in a lower profile than E-E however a thinner board must be used. A
thinner sensor can be obtained by FCOF (flip chip on flex) packaging of the MX8681 bumped die. The
maximum mounting height of the DFN package is 1.1 mm whereas the chip height is about 0.4 mm.
MX8681
Drawing No. 0868109
PCB top layer: (scale 1X)
Flex circuit
Cross Section (drawing not to scale)
PCB bottom layer: (top view, 1X)
Copper stamping, thickness as required
MX8681
MX8681
7
(2) E14 planar cores
Flex circuit: (component side, 1X)
IXYS
www.claremicronix.com
03/03/08