ACS704 Allegro Micro Systems, Inc., ACS704 Datasheet - Page 17

• Manufacturer Part Number: ACS704
• Manufacturer: Allegro Micro Systems, Inc.

The Effect of PCB Layout on ACS704 Electrical Performance
Eight different PC boards were fabricated to characterize the effect of PCB design on the operating junction temperature of the
Hall-effect IC inside of the ACS704. These PC boards are shown in the figure below.
were conducted with the following test conditions:
ACS704ELC005-DS, Rev. 7
Tests were conducted at ambient temperature, T
14 gauge wires were used to connect a power supply to a single PC board. These wires carry the 15 A dc primary current during
the tests.
A 15 A dc primary current was applied to a single PC board containing an ACS704 device. This current flowed from pins 1 and 2
to pins 3 and 4 of the ACS704 package.
A 1 mA current was forced from the GND pin to the VCC pin by a Fluke 179 True RMS Multimeter. This was the only power
applied to pins 5-8 of the ACS704 package during testing.
The voltage required to force the 1 mA current from the GND pin to the VCC pin was measured after applying the 15 A primary
current for approximately 25 minutes. A graph similar to the graph below was used to determine the junction temperature of the
ACS704.
An ACS704 device was soldered onto each PC board before beginning the thermal testing. Thermal management tests
Voltage vs. Temperature Curve used to Determine Die Junction Temperature
2 oz. Cu on one side of board
ACS704ELC-005
A
= 20°C. All tests were conducted in still air.
2 oz. Cu on both sides of board
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
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