Application Note
12
<Revision 1.0>
<2017-08-21>
EVAL-M1-099M-C User Manual
iMOTION™ Modular Application Design Kit
Schematics and Layout
5.2
Current feedback
Current Feedback Gain—the control on this board has an internal current feedback amplifier which has default
gain. The user can use this gain to count the current sensing range and Internal Itrip. An example is shown in
Figure 6. The sample resister is 0.25
Ω
.
𝑅17 = 𝑅13 ∗ 1.5,
𝑅16 = 𝑅13 ∗ 3
When input = 0V, IFBO = 601mV
Current Feedback 𝐺𝑎𝑖𝑛 =
𝑅13
𝑅14
=
7.68𝐾
5.9𝐾
= 1.302
Current sensing range is depending on current sample resister.
Current sensing range =
0.599
Current Gain ∗ Sample resister
Current sensing range =
0.599
1.302∗0.25Ω
= 1.84𝐴
The part of protect circuit, when using single shunt: Iu current feedback OPAMP internal Itrip can protect
overcurrent if the system response designed as demand.
Internal Itrip =
IC maximum specification Itrip level − 0.601V
Current Gain∗ Sample register
Internal Itrip =
1.306V−0.601V
1.302∗0.25Ω
=
2.17A
When using leg shunt. The gate kill signal from power module works. That is protected by outside IRMCK099.
When using single shunt. IV+ and IV- connect GND.
Figure 6 depicts the Eval-M1-099M evaluation board is suitable for single shunt and leg shunt for current
feedback.
Figure 6
The part of Current feedback on the Eval-M1-099M evaluation board