Datasheet ACS724 (Allegro) - 28
| Manufacturer | Allegro |
| Description | Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package |
| Pages / Page | 33 / 28 — Automotive-Grade, Galvanically Isolated Current Sensor IC. ACS724 |
| File Format / Size | PDF / 1.7 Mb |
| Document Language | English |
Automotive-Grade, Galvanically Isolated Current Sensor IC. ACS724
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Automotive-Grade, Galvanically Isolated Current Sensor IC ACS724 with Common-Mode Field Rejection in a Small-Footprint SOIC8 Package Thermal Rise vs. Primary Current ASEK724/5 Evaluation Board Layout
Self-heating due to the flow-off current should be considered dur- Thermal data shown in Figure 2 was collected using the ing the design of any current sensing system. The sensor, printed ASEK724/5 Evaluation Board (TED-85-0740-003). This board circuit board (PCB), and contacts to the PCB will generate heat includes 1500 mm2 of 2 oz. copper (0.0694 mm) connected to as current moves through the system. pins 1 and 2, and to pins 3 and 4, with thermal vias connecting The thermal response is highly dependent on PCB layout, copper the layers. Top and bottom layers of the PCB are shown below in thickness, cooling techniques, and the profile of the injected cur- Figure 3. rent. The current profile includes peak current, current “on-time”, and duty cycle. While the data presented in this section was collected with direct current (DC), these numbers may be used to approximate thermal response for both AC signals and current pulses. The plot in Figure 2 shows the measured rise in steady-state die temperature of the ACS724 versus DC input current at an ambi- ent temperature, TA, of 25 °C. The thermal offset curves may be directly applied to other values of TA.
Figure 3: Top and Bottom Layers Figure 2: Self Heating in the LA Package for ASEK724/5 Evaluation Board Due to Current Flow
Gerber files for the ASEK724/5 evaluation board are available for The thermal capacity of the ACS724 should be verified by the download from our website. See the technical documents section end user in the application’s specific conditions. The maximum of the ACS724 device webpage. junction temperature, TJ(MAX) (165°C), should not be exceeded. Further information on this application testing is available in the DC and Transient Current Capability application note on the Allegro website. 28 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
Automotive-Grade, Galvanically Isolated Current Sensor IC ACS724 with Common-Mode Field Rejection in a Small-Footprint SOIC8 Package Thermal Rise vs. Primary Current ASEK724/5 Evaluation Board Layout
Self-heating due to the flow-off current should be considered dur- Thermal data shown in Figure 2 was collected using the ing the design of any current sensing system. The sensor, printed ASEK724/5 Evaluation Board (TED-85-0740-003). This board circuit board (PCB), and contacts to the PCB will generate heat includes 1500 mm2 of 2 oz. copper (0.0694 mm) connected to as current moves through the system. pins 1 and 2, and to pins 3 and 4, with thermal vias connecting The thermal response is highly dependent on PCB layout, copper the layers. Top and bottom layers of the PCB are shown below in thickness, cooling techniques, and the profile of the injected cur- Figure 3. rent. The current profile includes peak current, current “on-time”, and duty cycle. While the data presented in this section was collected with direct current (DC), these numbers may be used to approximate thermal response for both AC signals and current pulses. The plot in Figure 2 shows the measured rise in steady-state die temperature of the ACS724 versus DC input current at an ambi- ent temperature, TA, of 25 °C. The thermal offset curves may be directly applied to other values of TA.
Figure 3: Top and Bottom Layers Figure 2: Self Heating in the LA Package for ASEK724/5 Evaluation Board Due to Current Flow
Gerber files for the ASEK724/5 evaluation board are available for The thermal capacity of the ACS724 should be verified by the download from our website. See the technical documents section end user in the application’s specific conditions. The maximum of the ACS724 device webpage. junction temperature, TJ(MAX) (165°C), should not be exceeded. Further information on this application testing is available in the DC and Transient Current Capability application note on the Allegro website. 28 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com