AMIS-30621-UGA 参数 Datasheet PDF下载

AMIS-30621 LIN Micro-stepping Motor Driver

8.0 Package Thermal Resistance

8.1 SOIC-20

Data Sheet

To lower the junction-to-ambient thermal resistance, it is recommended to connect the ground leads to a PCB ground plane layout as

illustrated in Figure 3. The junction-to-case thermal resistance is depending on the copper area, copper thickness, PCB thickness, and

number of copper layers. Calculating with a total area of 460 mm

2

, 35µm copper thickness, 1.6mm PCB thickness and 1layer, the

thermal resistance is 28°C/W, leading to a junction-ambient thermal resistance of 63°C/W.

Figure 3: PCB Ground Plane Layout Condition

SOIC-20

PC20041128.1

8.2 NQFP-32

The NQFP is designed to provide superior thermal performance. Using an exposed die pad on the bottom surface of the package is

partly contributing to this. In order to take full advantage of this, the PCB must have features to conduct heat away from the package. A

thermal grounded pad with thermal vias can achieve this. With a layout as shown in Figure 4 the thermal resistance junction – to –

ambient can be brought down to a level of 25°C/W.

NQFP-32

PC20041128.2

Figure 4: PCB Ground Plane Layout Condition

AMI Semiconductor

– Sept. 2007, Rev 1.5

5

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